Site 503: Eastern Equatorial Pacific

3. SITE 503: EASTERN EQUATORIAL PACIFIC1

Shipboard Scientific Party2

HOLE 503

Date occupied: 6 September 1979Date departed: 7 September 1979Time on hole: 16 hr.Position: 4°03.04'N, 95°38.21'WWater depth (sea level; corrected m; echo-sounding): 3672Water depth (rig floor; corrected m; echo-sounding): 3682Penetration (m): 4.78Number of cores: 1Total length of cored section (m): 4.78Total core recovered (m): 4.78Core recovery (Vo): 100Oldest sediment cored:

Depth sub-bottom (meters): 4.78Nature: Siliceous marlAge: QuaternaryMeasured velocity (km/s): 1.5206

HOLE 503A

Date occupied: 7 September 1979Date departed: 11 September 1979Time on hole: 88.3 hr.Position: 4°04.04'N, 95°38.21'WWater depth (sea level; corrected m; echo-sounding): 3672Water depth (rig floor; corrected m; echo-sounding): 3682Penetration (m): 235.0Number of cores: 54Total length of cored section (m): 235.0Total core recovered (m): 138.16

1 Prell, W. L., Gardner, J. V., et al., Init. Repts. DSDP, 68: Washington (U.S. Govt.Printing Office).

2 Warren L. Prell (Co-Chief Scientist), Department of Geological Sciences, Brown Uni-versity, Providence, Rhode Island; James V. Gardner (Co-Chief Scientist), Pacific-ArcticBranch of Marine Geology, U.S. Geological Survey, Menlo Park, California; Charles Adel-seck, Deep Sea Drilling Project, Scripps Institution of Oceanography, La Jolla, California(present address: McClelland Engineers, Ventura, California); Gretchen Blechschmidt, La-mont-Doherty Geological Observatory, Columbia University, Palisades, New York (presentaddress: Exxon Production and Research Corp., Houston, Texas); Andrew Fleet, Depart-ment of Earth Sciences, Open University, Buckinghamshire, United Kingdom (present ad-dress: Geochemistry Branch Explor. and Prod. Division British Petroleum Research Center,Sudbury-on-Thames, Middlesex TW16 7LN United Kingdom); Lloyd Keigwin, Jr., GraduateSchool of Oceanography, University of Rhode Island, Kingston, Rhode Island (present ad-dress: Woods Hole Oceanographic Institution, Woods Hole, Massachusetts); Dennis Kent,Lamont-Doherty Geological Observatory, Columbia University, Palisades, New York; Mi-chael T. Ledbetter, Department of Geology, University of Georgia, Athens, Georgia; UlrichMann, Institut fur Sedimentforschung, Universitàt Heidelberg, Heidelberg, Federal Republicof Germany; Larry A. Mayer, Graduate School of Oceanography, University of Rhode Is-land, Kingston, Rhode Island; William R. Riedel, Geological Research Division, Scripps In-stitution of Oceanography, La Jolla, California; Constance Sancetta, Lamont-Doherty Geo-logical Observatory, Columbia University, Palisades, New York; Dann Spariosu, Lamont-Doherty Geological Observatory, Columbia University, Palisades, New York; Herman B.Zimmerman, Department of Geology, Union College, Schenectady, New York.

Core recovery (%): 58.8Oldest sediment cored:

Depth sub-bottom (meters): 234.74Nature: Siliceous nannofossil oozeAge: late MioceneMeasured velocity (km/s): 1.5567Shear strength (g/cm2): 1119.75

HOLE 503B

Date occupied: 11 September 1979Date departed: 13 September 1979Time on hole: 52.0 hr.Position: 4°03.02'N, 95°38.32'WWater depth (sea level; corrected m; echo-sounding): 3672Water depth (rig floor; corrected m; echo-sounding): 3682Penetration (m): 112.8Number of cores: 26Total length of cored section (m): 112.8Total core recovered (m): 94.17Core recovery (%): 83.5Oldest sediment cored:

Depth sub-bottom (meters): 111.12Nature: Siliceous nannofossil oozeAge: Lower PlioceneMeasured velocity (km/s): 1.5002Shear Strength (g/cm2): 247.5

BACKGROUND AND OBJECTIVESOur primary objective at Site 503 (Fig. 1) was to re-

cover a complete, undisturbed Neogene and Quaternarysection in the eastern equatorial Pacific. Site 503 is lo-cated near Site 83 in an area that contains an almostcontinuous pelagic record of the past 10 m.y. (Hays etal., 1972). Unfortunately, Site 83 was only spot-cored,and the recovered sediment is so badly disturbed by ro-tary drilling that most of the detailed record is lost. Thesection has an average sedimentation rate of 2.0 to 2.5cm/k.y. with good-to-moderate preservation of all themajor microfossil groups. We returned to Site 83 to corethe same section, using the Hydraulic Piston Corer(HPC) to obtain an undisturbed, continuous section forhigh-resolution stratigraphic studies.

The quality of these HPC cores, together with thedata already collected at Site 502, should allow a high-resolution intercalibration of the Neogene and Quater-nary magnetostratigraphy with both Atlantic and Pa-cific equatorial biostratigraphy. In addition, the evolu-tion of equatorial microfossils throughout the late Neo-gene and Quaternary are now available for study in onesection, with excellent time control. The detailed history

163

SITE 503

15'

10c

75°Figure 1. Location of Site 503 and Site 83 (Leg 9) in the eastern equatorial Pacific. Both sites lie on the north flank of the Galapagos Ridge within the

symbol for Site 503.

of Oceanographic conditions in this area, revealed byfluctuations in isotopes, calcium carbonate and opal con-tents, and faunal and floral assemblages, can now bestudied. Sediment at Site 503, in combination with thedata from Site 502, should also record changes in sur-face circulation and trade wind intensity. These sitesalso contain information on the timing of the closing ofthe Isthmus of Panama and initiation of Northern Hemi-sphere glaciation.

OPERATIONSWe departed Balboa, Panama, at 0012 hr. on 3 Sep-

tember 1979, deployed the geophysical gear at 0015 hr.,and steamed toward the vicinity of Site 503 (Fig. 1). Ourcourse paralleled that of Glomar Challenger Leg 9(GC-9) from Site 83 (our destination) to Balboa, so wewere able to follow our progress by referring to the GC-9profiles (Fig. 2). Speed was reduced to 5 knots at 0305hr. on 7 September because the seismic reflection profileclosely resembled the profile over Site 83 (Fig. 2). Wedropped the beacon at 0332 hr., retrieved the geophys-ical gear, and by 0400 hr. were stationed over the bea-

con. Site 503 is located at 4°04.4'N, 95°38.21'W at awater depth of 3672 meters (corrected), about 11 kmeast of Site 83. The track line of our approach and de-parture is shown in Figure 3. A summary of the drillingdata is given in Table 1.

Core 1 from Hole 503 was retrieved on 7 Septemberat 1430 hr. and was a full core. We raised the drill string3.0 meters and started again so that the sediment/waterinterface would be recovered. We designated this secondcore Core 503A-1 and commenced coring Hole 503A.The operation was plagued with core catcher failures,especially with the flapper type, and core liner fractur-ing. We cored Hole 503A to a total depth of 235 meters(Core 54), then stopped to avoid piston coring basaltcalculated to be at 240 meters. Recovery for Hole 503Awas only 58.8%, principally because of core catcherfailures. Rust contamination from the drill pipe was ob-vious once we started using pipe that had not been usedat Site 502. This contamination caused a severe degrada-tion of the paleomagnetic data.

Hole 5O3B was offset 100 meters to the southwestof Hole 5O3A and was cored continuously, again from

164

SITE 503

East West

Site 83

EüüE*Sk,^:i,£

% 8

- 1

- 2

0930Z 0900Z 0830Z 0800Z0736Z c/s to 10 kts 080° 20 Jan 1979

0730Z

- 4

0130Z2330Z

Figure 2. Seismic profiles across Site 503 (GC-68), filtered at 80/640 Hz, and Site 83 (GC-9).

0230Z 0332Z 0400ZDrop Beacon

the sediment/water interface. Two modifications to theHPC were made for Hole 503B: (1) We reversed thebevel on the flapper-type core catchers so that the forceof the sediment on the flapper would tend to close it,and (2) we chose to use only one small shear pin ratherthan three. This latter change allowed the HPC to"fire" at 800 to 1000 psi rather than 1800 to 2000 psi.We felt that the shock of the HPC striking the sedimentat a high velocity and its rapid deceleration at the end ofthe stroke may have caused some of the disturbance inHole 5O3A.

These modifications were significant. The recovery atHole 5O3B, both in amount and quality, was greatly im-proved compared with Hole 5O3A. However, contami-nation by rust continued to be a problem. Hole 5O3Bwas continuously cored from the sediment/water inter-face to 112.8 meters sub-bottom, with a recovery of83.5%. We terminated coring at 0354 hr. on 13 Sep-tember because of time constraints on our arrival in Sa-linas, Ecuador.

The geophysical gear was deployed by 1704 hr. on 13September. We steamed to the northwest, then came

165

SITE 503

4°20'

4°00'

3°40'

Table 1. Coring summary for Site 503.

96°00' 95°30' 95°05'

Figure 3. Approach and departure of GC 68 (solid line) from Site 503.Dashed track line is GC 9 departure from Site 83.

about and crossed over the beacon at Site 503 and con tinued on to the port of Salinas.

LITHOSTRATIGRAPHYThe section at Site 503 consists of one major litho

logic facies that can be divided into three units. Theseunits are defined on the basis of oxidation state and claycontent of the sediment. The lithostratigraphic divisionof Site 503 and the ages of the units are given in Table 2.Smear slide summaries for major and minor lithologiesare given in Table 3 (see Appendix, this chapter). •

Major LithofaciesThe section at Site 503 is composed of three sediment

types: (1) siliceous bearing nannofossil marl, (2) calcar eous siliceous ooze, and (3) siliceous nannofossil ooze.Slight variations in composition and microfossil pres ervation occur throughout the section but are not usefulfor subdivision. Color cycles, apparently with a uniformperiodicity, are marked and occur throughout.

Unit A (0 8.45 m sub bottom)Unit A is composed of intervals of very dark grayish

brown iron oxide and silica bearing nannofossil marland calcareous bearing siliceous ooze that alternates withlight yellowish brown and very pale brown silica bearingnannofossil marl and silica bearing nannofossil ooze.Gradations between these sediment types are common.Burrows and mottles are common. Most color bounda ries are gradational and/ or burrowed, but some sharpboundaries occur near the base of darker lithologies.

Sedimeηt in Unit A is uniform in composition. Clayis commoh (5 25%) to abundant (25 75%), but varia tion in clay content does not appear to correlate withcolor cycles. Foraminifers are common (5 25%) andmoderately to poorly preserved. Nannofossils are abun dant (25 75%), and diatoms and radiolarians are com mon (5 25%). Iron oxides are rare (1 5%) in the lighter colored sediment and common (5 25%) in the darker colored material. Sponge spicules, silicoflagellates, andvolcanic glass sporadically occur in rare (1 5%) to trace(< 1%) amounts.

DateCore (SeptemberNo.

Hole 503

1

Hole 5O3A

123456789

101112131415161718192021222324252627282930313233343536373838404142434445464748495051525354

Total

Hole 5O3B

123456789

1011121314151617181920212223242526

Total

1979)

7

7777788888888888888879999999999999999

1010101010101010101010101011111111

1111111111111111111212121212121212121212121212131313

Time(hr.)

164218232022220323330123025404170536070508250947112813051432160517351850201223152315004702230342045906300809095311141300141615291655192721032240235701260301042005370954123213541524165218101940211823040059021503400508

10481220134215201702181619252105223102210356053607070828095911341252140916301908202921472330010602300354

Depth fromDrill Floor

(m)Top Bottom

3678.8 3083.0

3679.9 3680.63680.6 3685.03685.0 3689.43689.4 3693.83693.8 3698.23698.2 3702.63702.6 3707.03707.0 3711.43711.3 3715.83715.8 3720.23720.2 3724.63724.6 3729.03729.0 3733.43733.4 3737.83737.8 3742.23742.2 3746.63746.6 3751.03751.0 3755.43755.4 3759.83764.2 3768.63764.2 3768.63768.6 3773.03773.0 3777.43777.4 3781.83781.8 3786.23786.2 3790.63790.6 3795.03795.0 3799.43799.4 3803.83803.8 3808.23888.2 3812.63812.6 3817.03817.0 3821.43821.1 3825.83825.8 3830.23830.2 3824.63834.6 3839.03839.0 3843.43843.4 3847.83844.8 3852.23852.2 3856.63856.6 3861.03861.0 3865.43865.4 3869.83869.8 3874.23874.2 3878.63878.6 3883.03883.0 3887.43887.4 3891.83891.8 3896.23896.2 3900.63900.6 3905.03905.0 3909.43909.4 3913.8

3678.8 3681.63681.6 3686.03686.0 3690.43690.4 3694.83694.8 3699.23699.2 3703.637O3.6 37O8.O3708.0 3712.43712.4 3716.83716.8 3721.23721.2 3725.63725.6 3730.03730.0 3734.43734.4 3738.83738.8 3743.23743.2 3747.63747.6 3752.03752.0 3756.43756.4 3760.83760.8 3765.23765.2 3769.63769.6 3774.03774.0 3778.43778.4 3782.83782.8 3787.23787.2 3791.6

Depth belowSeafloor

(m)Top Bottom

0 4.4

0 1.81.8 6.26.2 10.6

10.6 15.015.0 19.419.4 23.823.8 28.228.2 32.632.6 37.037.0 41.441.4 45.845.8 50.250.2 54.654.6 59.059.0 63.463.4 67.867.8 72.272.2 76.676.6 81.081.0 85.485.4 89.889.8 94.294.2 98.698.6 103.0

103.0 107.4107.4 111.8111.8 116.2116.2 120.6120.6 125.0125.0 129.4129.4 133.8133.8 138.2138.2 142.6142.6 147.0147.0 151.4151.4 155.8155.8 160.2160.2 164.6164.6 169.0169.0 173.4173.4 177.8177.8 182.2182.2 186.6186.6 191.0191.0 195.4195.4 199.8199.8 204.2204.2 208.6208.6 213.0213.0 217.4217.4 221.8221.8 226.2226.2 230.6230.6 235.0

0.0 2.82.8 7.27.2 11.6

11.6 16.016.0 20.420.4 24.824.8 29.229.2 33.633.6 38.038.0 42.442.4 46.846.8 51.251.2 55.655.6 60.060.0 64.464.4 68.868.8 73.273.2 77.677.6 82.082.0 86.486.4 90.890.8 95.295.2 99.699.6 104.0

104.0 108.4108.4 112.8

LengthCored

(m)

4.4

1.84.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.4

235.0

2.84.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.44.4

112.8

LengthRecovered

(m)

4.78

1.733.76

3 . 154.150.024.12—3.483.644.213.854.233.263.973.061.450.062.934.354.20—2.664.10

_0.99—4.172.864.47 r0.70 ?1.183.560.773.382.710.063.051.014.213.993.543.97—1.151.003.651.904.355.233.863.834.15

138.16

2.642.944.354.234.194.364.204.350.344.214.574.073.654.074.294.273,984.433.712.864.714.671.172.602.602.72

94.17

Recovery

108.6

97.285.5_

71.694.3

cc only93.6_

79.182.795.787.5096.174.190.269.533.0

1.466.698.996.8—

60.093.4

—33.0—

93.669.3

103.417.036.888.220.578.664.8

1.673.630.996.491.180.590.2

26.122.783.044.598.973.487.789.094.358.8

94.366.899.6196.1495.2399.0995.4598.86

7.7295.68

103.892.583.8692.597.597.0490.45

100.6884.3265.00

107.05106.1426.5959.0959.0961.8283.5

166

SITE 503

Table 2. Lithostratigraphy summary for Site 503.

Unit

A

B

C

Hole

5035O3A5O3B

5O3A5O3B

5O3A

Core/Section

1-1 to 1,CC1-1 to 2,CC1-1 to 3,CC

4-1 to S2.CC3-1 to 26.CC

53-1 to 54,CC

DepthSub-bottom

(m)

0-8.45

8.45-226.2

226.2-235.0

Age(m.y.)

0-0.4

0.4-7.5

7.5-7.8

Description

Oxidized dark brown and orange silica-bearing-nannofossil marl alternatingwith calcareous-bearing siliceousooze with manganese and ironoxides-hydroxides.

Reduced dark greenish to very palegreenish yellow silica-bearingnannofossil marl alternating withcalcareous siliceous ooze gradationalfrom dark at the top to light at thebase. Clay content decreases down-section.

Reduced dark greenish to pale greenishyellow siliceous nannofossil marlalternating with calcareous-silica-bearing clay. Contains pyrite andgreater than 25% clay.

The yellowish brown to brown silica-bearing nanno-fossil marl of Unit A overlies a pale olive silica-bearingnannofossil marl. We use this color change as the bound-ary between Units A and B.

Unit B (8.45-226.20 m sub-bottom)Unit B is composed of silica-bearing nannofossil marl,

calcareous siliceous ooze, and siliceous nannofossil oozethat contains small amounts of pyrite and has colorscharacteristic of reduced oxidation states. The unit hassmall-scale variations of both color and compositionthat have a range similar to the overall gradationaltrends in the section.

Color cycles in the uppermost part of the unit are inthe green hue—from greenish black to light greenishgray. The colors lighten downsection, hues of yellowand yellow green beginning below 30 meters sub-bot-tom. Brownish hues appear below 170 meters sub-bot-tom as minor constituents of the total range in color;however, the overall aspect of the colors continues tolighten downsection.

Clay content in Unit B decreases with depth. Claycomprises less than 10% of the sediment in the domi-nant lithologies. Below 220 meters, clay content in-creases and exceeds 25% abundance below 226.2 me-ters, which marks the boundary with Unit C. Calciumcarbonate content exhibits high-frequency fluctuationsthroughout the unit (see Gardner, this volume). Silicacontent is variable and does not show a consistent trendwithin the unit.

We chose the boundary between Units B and C wherethe clay content rapidly increased to more than 25%.The transition to over 25% clay abundance occurs be-tween Cores 52 and 53 of Hole 5O3A at 226.2 meterssub-bottom.

Unit C (226.20-234.75 m sub-bottom)Unit C is composed of siliceous nannofossil marl, sil-

ica-bearing nannofossil marl, and calcareous- and silica-bearing clay, all of which are enriched in clay in com-parison to the overlying sediment. The colors of Unit Care somewhat darker than those of the overlying sedi-ment. Clay is abundant (25-75%) but varies greatly.The proximity of the base of this unit to basement (weestimate the bottom of Hole 5O3A is within 10 m of oce-

anic crust) suggests that the clay may reflect a hydro-thermal or thermal alteration of the sediment (see Ba-ker, this volume). These basal clays are composed pre-dominantly of smectite minerals (see Zimmerman, thisvolume). Foraminifers are rare (1-5%) to absent. Nan-nofossils are common (5-25%) to abundant (25-75%),and unspecified carbonate is common. Diatoms andradiolarians are uniformly common (5-25%). Minoramounts of pyrite, ash, and silicoflagellates make up theremainder of the sediment.

DiscussionThe lithofacies at Site 503 have several interesting

aspects. The abrupt change from reduced to oxidizedsediment at 8.45 cm sub-bottom (see Frontispiece, thisvolume, and core photographs) is similar to that at Site502 in the western Caribbean. The significance of thisevent is not well understood, but it apparently representspostdepositional reduction of the sediment. Clay miner-als throughout the section are dominated by smectitesthat probably reflect halmyrolytic formation of the claysby convection of pore waters that are thermally driven.The large increase in clay mineral content in Unit C mayreflect the proximity of altered basaltic rocks. Unit Bhas trace amounts of illite and rare amounts of chloriteand kaolinite, whereas abundant occurrences of chloriteand kaolinite and rare amounts of illite occur in Unit A.Smectite is still the dominant clay mineral; however, thesmall increase in detrital clay input may reflect a changein Oceanographic current patterns in the Holocene.

Several horizons of dispersed ash occur throughoutthe section (see Ledbetter, this volume). The Mioceneand lowermost Pliocene sections contain only traceamounts of ash at infrequent intervals. However, sev-eral lower Pliocene through Quaternary horizons con-tain abundant dispersed ash, with the greatest incidencein the uppermost Quaternary. The ash in the lowermostsection is dominantly dark glass, whereas the upper sec-tion is dominated by light glass (see smear slide sum-mary, Table 3).

Large nodules of microcrystalline rhodochrosite,MnCO3, (Fig. 4) occur within Units B and C from 19.4meters to the base of the section (last occurrence in Sam-ple 5O3A-53-2, 13 cm at 227.8 m sub-bottom) (see Cole-man et al., this volume). Semiindurated carbonate oc-curs around burrows at about 13 meters. The nodulesare most abundant in the interval from 19.4 to 80 meterssub-bottom and appear to have formed around bur-rows. This relationship suggests that either the burrow-ing organism or the burrows themselves created a geo-chemical microenvironment favorable to the subsequentprecipitation of rhodochrosite. Several nodules shownot only the major burrow but additional burrows inter-secting the major one.

Biogenic parts (briefly discussed and figured in theSite 502 chapter, this volume) appear scattered through-out the section in trace abundances. The most commonelement found is probably a hook from a squid arm (C.B. Miller, personal communication).

Bioturbation is common to abundant throughout thesection (Figs. 5 and 6). Mottles commonly are "reaction

167

SITE 503

581—

59

60

61

62

63

64

V *f •

"

65cm

Figure 4. Rhodochrosite nodule from Sample 503B-2, 58-65 cm. Thenodule apparently formed around a burrow.

rims" around burrows. In some instances, concentricmillimeter-thick dark laminae enriched in pyrite encircleburrows. Intense bioturbation occurs in numerous inter-vals. Burrows are most evident at sharp color changesand they are very often pyritized. Zoophycus are com-mon throughout the section. Open burrows are com-mon in Unit B (Fig. 6) from 9.3 to 64 meters sub-bot-tom. These burrows have cemented walls that are gener-ally pyritized. Fecal pellets occur in one burrow at 9.3meters (Fig. 6).

Color cycles are a dominant feature of this section.The color changes reflect lithologic composition, espe-

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

1001-

<A V

m

:f

Figure 5. Example of undisturbed burrows in Sample 24A-2, 80-100cm at approximately 100 meters sub-bottom. Little to no distor-tion occurs along the sides of the core.

dally carbonate content. We measured the lengths of thecolor cycles as the distance between the tops of consecu-tive layers of the same shade (Fig. 7). The lengths of thecycles in Hole 5O3A show a wide range that may reflecta change in sedimentation rates. A shift to longer cyclesoccurs at the bottom of Hole 503A (Fig. 7). A singlestrong mode occurs at 80 to 100 cm per color cycle downto 110 meters depth. This corresponds to a periodicityof 32 to 40 k.y. per cycle if we use an estimate of a 2.5

168

SITE 503

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73 L_cm

Figure 6. Open burrows and a burrow filled with fecal pellets in Sam-ple 503B-3-2, 53-73 cm (approximately 9 m sub-bottom). Thesestructures illustrate the undisturbed nature of HPC cores. Seefrontispiece, this volume, for a color photograph of these features.

cm/k.y., for the sedimentation rate. This estimate isslightly biased to shorter periodicities, because we ig-nored the layer at the top and the bottom of each coreand the change of the longer rather than the shorter cy-cles straddling core breaks is greater. Carbonate contentalso shows a cyclic variation (Fig. 8) (Gardner, this vol-ume), with periodicities similar to those of color cycles.

Our lithostratigraphic subdivision differs from thatat Site 83 (Hays et al., 1972). The lithostratigraphy atSite 83 is subdivided into three formations (ClippertonOceanic Formation, San Bias Oceanic Formation, andLine Island Oceanic Formation), and the San Bias Oce-anic Formation is further subdivided into three units.Our subdivision of the section is compared to that ofSite 83 in Table 4. Our Unit A can be correlated with theClipperton Oceanic Formation. Unit B correlates roughlywith the San Bias Oceanic Formation but differs insome aspects. We do not recognize the increased carbon-ate content in the upper section of our Unit B that wasnoted by Hays et al. (1972) in their Unit 1 of the SanBias Oceanic Formation. We also did not detect a changein the frequency of burrowing in our Unit B that hadbeen noted in Unit 3 of the San Bias Oceanic Forma-tion. The carbonate nodules that are so abundant at Site503 apparently were not found at Site 83. We believethese differences are simply the result of the differencesin quality of HPC versus rotary-drilled samples. OurUnit C correlates to an unrecovered interval above theLine Islands Oceanic Formation at Site 83. Site 503 didnot penetrate a facies that correlates to the Line IslandsOceanic Formation at Site 83.

PHYSICAL PROPERTIESStandard DSDP methods (Boyce, 1976, 1977) were

used for the analyses of physical properties at Site 503(see Introduction and Explanatory Notes for details).Zones of obvious sediment disturbance were not sam-pled or analyzed. Vane shear and penetrometer mea-surements were made on split cores. One sample percore (usually from Section 2) of known volume was takenand sealed with rubber cement. A 2-minute GRAPE countwas run on these subsamples. They were then refrig-erated in sealed containers to await additional analysisashore. A detailed discussion of the results appears inMayer (this volume).

Low values of shear strength occur in the uppermostsection at Site 503 (Fig. 9). The expected increase ofshear strength with depth, however, occurs only to adepth of about 15 meters, where a value of about 400gm/cm2 occurs. Shear strength below this depth re-mains fairly constant but with small variations down toabout 210 meters sub-bottom. Shear strength rapidly in-creases at about 210 meters to a maximum of 1686g/cm2 at 224 meters. The lack of an increase in shearstrength with depth in the upper 200 meters of the sedi-ment column implies that the sediment is extremely un-dercompacted. This is consistent with the associatedhigh porosities and water contents. The cause of theundercompaction may be the high percentage of bioge-nous silica. The spiney biogenous tests may mechan-ically interlock to form a supporting framework. Thesmall variations about the mean in shear strength maybe due to subtle lithologic changes. The rapid increase inshear strength at 210 meters probably reflects the in-crease in the clay content (see Lithostratigraphy) to-gether with the collapse of the interlocking frameworkdue to the weight of the overburden, the dissolution and

169

SITE 503

50

100

a.ΦQ

150

200

235

I23456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354

bO3A

Cycle Length (cm)100 200 300 503B

X5 0 3 AΦ 5 0 3 B

119 139 159 179Cycle Length (cm)

199 219 239 259 279 299

Figure 7. The distribution of the length (cm) of color cycles versus sub bottom depth (m) in Holes 5O3A and 5O3B. A histogram of cy cle length is also shown. Note the strong mode at 80 100 cm for the combined data at depths less than 110 meters.

170

SITE 503

CaCO3%503A

50.0 100.0 0.0

503B

50.0

Shear Strength (g/cm )O O o O O CIn in o in cCN in r

o o o o o oin o m o m oCM in r~ o CM inCN CN CN C3 CJ CO

2 2 5 •

Figure 8. The variation of calcium carbonate content with sub bottomdepth in Holes 5O3A and 5O3B. (From Gardner, this volume.)

Table 4. Correlation of lithostratigraphic units between Site 83 andSite 503.

Site 503Lithostratigraphic

Unit

Unit AUnit B

U nitC

Depth(m)

0 8.58.5 226.2

226.2 235

Site 83Lithostratigraphic

Unit

Clipperton Oceanic Fm.San Bias Oceanic Fm.

Unit 1Unit 2Unit 3

Line Islands Oceanic Fm.

Depth(m)

0 12.612.6 22212.6 49.649.6 150.0

150.0 222.0232.9 234.4

20

40

60

80

o 120ü

Q 140

160

180

200

220

240

503A - o503B - 0

Figure 9. The variation of shear strength (g/cm2) with sub-bottomdepth in Holes 5O3A and 5O3B.

reprecipitation of silica, or possibly a thermal effectcaused by proximity to basement. Biostratigraphy vir-tually eliminates a major hiatus at this depth.

In order to place the vane shear measurements in theproper perspective, shear strengths were determined onseveral calibration samples. Each sample was run tentimes with the utmost of care. The shear strength ofday-old Jewish rye bread dough (without seeds) wasfound to be 47.53 g/cm2. Cream cheese proved to havea strength of 66.13 g/cm2. Ginger cookie dough hadvalues of 70.26 g/cm2. A value could not be determinedfor lime jello, probably because of the large pineappleinclusions interspersed throughout the host material. Sev-eral attempts were made to measure the shear strengthof chocolate chip cookie dough, but in each case thecookies were eaten before a measurement could be made.

The penetrometer data (Fig. 10) also indicate that thesection is undercompacted, although the data seem to beslightly more sensitive to small amounts of compactionthat have occurred. The general trend shows a very gen-tle decrease in penetration down to about 210 metersafter a rapid decrease from very high (>4.4 cm) values

171

SITE 503

1.00

Penetration (cm)

2.00 3.00 4.00

20

40

60

80

100

120

140

160

180

200

220

1.40 1.500

Velocity (km/s)1.60 1.70 1.80 1.90

503A O503B O

o o

Figure 10. The variation in penetrometer penetration (cm) with sub bottom depth in Holes 5O3A and 5O3B.

in the uppermost sediment. Very large scale, high fre quency fluctuations in penetration are superimposed onthis trend. These fluctuations appear to be the result oflithologic variations. High frequency fluctuations endbelow 210 meters sub bottom, and penetration valuesdrop below about 1.4 cm. This drop in values coincideswith the zone of increased shear strength.

P wave velocities were measured both through theliner and on chunk samples. The velocity values are ex tremely low (Vp = 1.515 km/ s) and are typical of highlysiliceous sediment. The velocity curve (Fig. 11) is char acterized by high frequency, low amplitude fluctuations.The total range in values (1.495 1.570 km/ s) is onlyslightly greater than the precision of any one measure ment (5%), and we thus conclude that the velocity fluc tuations are insignificant. This constant velocity may inpart explain the absence of sub bottom reflections onthe 3.5 kHz profiles. The velocity baseline appears to in crease to 1.54 km/ s below 210 meters sub bottom. Thisincrease coincides with the increase in shear strengthand clay content discussed earlier.

Density, water content, and porosity were determinedby gravimetric analyses and continuous and 2 minuteGRAPE counts. Low densities (Fig. 12) and high poros

20503A o503B 0

60

80

100

S.120

140

160

180

200

220

240

Figure 11. The variation in seismic velocity (km/ s) with sub bottomdepth for Holes 503A and 5O3B.

ities and water contents occur throughout the section(Fig. 13). These data are also consistent with the ex tremely undercompacted nature of the section. Mini mum densities of 1.13 g/ cm3 are found between 30 and50 meters sub bottom, and maximum densities of 1.37g/ cm3 are found between 205 and 220 meters sub bot tom. Interestingly, the densities decrease in the deepestsamples, where shear strength and velocity increase. Thelack of a coincident increase in density in the bottom tenmeters of the section may imply that the shear strengthand velocity increases are due to a small increase in claycontent or a thermal effect.

SEISMIC CORRELATIONOn the approach to Site 503, the Glomar Challengers

seismic array consisted of a 40 in.3 and a 5 in.3 airgunthat were fired at 10 s intervals. Records were made at10 s sweep filtered at 80/160 Hz and at 5 s delayed sweepfiltered at 80/640 Hz. The 3.5 kHz profiler was in oper ation, but the record is of such low quality that it cannotbe used for high resolution studies of the section.

P wave velocities on individual samples from Site 503give an average velocity of 1.510 km/ s. No intervals ofhigh velocity or even a gradual increase in velocity occur

172

SITE 503

Bulk Density (g/cm3)30 40

1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80

220-

240 L

Figure 12. The variation in saturated bulk density (g/cm3) with sub-bottom depth for Holes 503A and 5O3B.

with depth in the section (Fig. 11). Therefore, we use aconstant 1.510 km/s to convert the time record to adepth section (Fig. 14).

Four acoustic units can be defined on the seismic pro-files. Acoustic Unit 1, from 0 to 16 meters, is an acous-tically transparent section that contains one reflector.Acoustic Unit 2, from 16 to 178 meters, is uniformlystratified with almost no variation in the distances be-tween internal reflectors. Acoustic Unit 3, from 178 to240 meters, differs from Acoustic Unit 2 in that the in-terval reflectors are not so uniformly spaced. AcousticUnit 4 is basaltic basement, based on the results fromSite 83 (Hays et al., 1972).

A rough correlation is observed between the acousticunits and the lithostratigraphic units (Fig. 14). How-ever, the boundary between Acoustic Units 2 and 3 doesnot coincide with the boundary between Lithostrati-graphic Units B and C.

BIOSTRATIGRAPHYSediment recovered at Site 503 represents a relatively

complete section from the Quaternary through the up-per part of the upper Miocene. The sediment containsboth calcareous and siliceous microfossils that are suffi-

20

40

60

80

100

120

g• 140Q

160

180

200

220

240

Water Content (%)50 60 70

- i r*— j -80 90

8

503A - o503B - 0

°o

Figure 13. The variation of water content (°7o) with sub-bottom depthin Holes 503A and 5O3B.

ciently numerous and well preserved to permit us tocompare the biostratigraphy of all major planktonicgroups. However, several problems became apparent.Nannofossils are affected by dissolution in the Quater-nary section. Reworking obscures some of the strati-graphically significant events near the Pliocene/Pleisto-cene boundary, in the lower Pliocene, and throughoutthe Miocene. Foraminifers are rarely well preserved orabundant and require the treatment of large samples toobtain sufficient number of specimens. Diatoms are rareand poorly preserved in the Quaternary section but aresomewhat better preserved in the Pliocene and becomeabundant and very well preserved in the Miocene sec-tion. This good preservation and an assemblage domi-nated by forms characteristic of the present Peru-ChileCurrent implies high silica productivity during the Mio-cene. Radiolarians are somewhat corroded and sparse inseveral cores near the Pliocene/Pleistocene boundaryand show some reworking of Miocene species into theentire section.

The Pliocene/Pleistocene boundary occurs in the up-per part of Core 503A-9 and the upper part of Core5O3B-1O if it is defined by the extinction of Discoasterbrouweri. But the boundary is higher (Cores 503A-7 and503 B-7) if it is defined by foraminifer al, radiolarian, or

173

SITE 503

SITE 503

o•16

178

2 4 0 •

1

2

3

B

C

Lithological Descript ion

Quasiperiodic alternations ofsilica-bearing nannofossilmarl and calcareous-bearingsiliceous ooze. Averagecarbonate content and clay con-tent increase with depth.

BASALT (Leg 9 results)

Figure 14. Seismic profile (GC68) was filtered at 80/640 Hz. The correlation with acoustic and litho-stratigraphic units at Site 503.

diatom datums. Poor sediment recovery and scarcity ofvarious marker species combine with reworking to makethe precise determination of the Pliocene/Pleistoceneboundary difficult. We subdivided the Pliocene into earlyand late intervals at the last appearance of the plank-tonic foraminiferal genus Sphaeroidinellopsis (Samples503A-20-2, 50 cm and 503B-19-2, 75 cm). The Miocene/Pliocene boundary at Site 503 is defined by the first ap-pearance of Globorotalia tumida in Sample 503-37,CC.Details of the diatom, radiolarian, calcareous nannofos-sil, and foraminiferal zonations are given in the follow-ing and are summarized in Figures 15 and 18.Calcareous Nannofossils

The section at Site 503 contains most of the nanno-fossil zones from early late Miocene to Quaternary age.Marked variations in abundance and preservation ofnannofossils occur throughout the section, so that sev-eral datums cannot be precisely determined. Reworkingof Miocene and Pliocene forms was noted throughoutthe section. A detailed discussion of the distribution ofPlio-Pleistocene calcareous nannofossils at Site 503 isfound in Rio (this volume). Here, we summarize theshipboard biostratigraphy of the calcareous nannofos-sils, with emphasis on epoch boundaries (Figs. 15 and18).

Biostratigraphic subdivision of the Quaternary sec-tion is hampered by poor preservation of nannofossils.However, all zones except the Emiliania huxleyi Acmeand the small Gephyrocapsa Zones (Gartner, 1977) arerecognized at Site 503. A short interval just above theuppermost occurrence of Helicopontosphaera sellii (Sam-ples 503A-5-2, 108 cm to 5O3A-5-3, 48 cm; Cores 5O3B-2, 40 cm to 5O3B-3, 40 cm) in which no large G. oce-anica were found may represent the small GephyrocapsaZone. A few reworked discoasters of Miocene and Plio-cene age are found near the base of the Quaternary.

The Pliocene/Pleistocene boundary as defined by thelast occurrence of the nannofossil Discoaster brouweriis somewhat difficult to determine in this section be-cause of reworking. Therefore we defined the boundaryby the first consistent downcore occurrence of D. brou-weri, which is located between Samples 503A-9-1, 108cm and 503A-9-2, 48 cm and between Samples 5O3B-1O-1, 40 cm and 5O3B-1O-2, 40 cm. The succession of dis-coaster extinctions in the upper Pliocene was easily de-termined (see Fig. 15). However, in the lower Pliocene,the top of the D. tamalis Zone (Samples 5O3A-13-3,48-108 cm; 503B-13-2, 40 cm to 5O3B-13-3, 40 cm) isdifficult to determine because of the sparsity of thisspecies at the top of its range. The Reticulofenestrapseudownbilica and D. asymmetricus zones could not

174

SITE 503

be differentiated in this section because of the rarity ofAmaurolithus tricorniculatus, which is used to definethe top of the D. asymmetricus Zone. However, thebase of the D. asymmetricus Zone occurs between Sam-ples 503A-26,CC and 503A-27,CC in Hole 5O3A and be-tween 5O3B-21,CC and 503B-22.CC in Hole 5O3B.

The Miocene/Pliocene boundary is placed at the lastconsistent occurrence of D. quinqueramus (Core 5O3A-33) at a sub-bottom depth of approximately 138 meters.Considerable reworking of nannofossils is apparent atthis boundary, as shown by specimens of D. quinque-ramus that occur as high as Core 5O3A-31.

Almost all of the Miocene sequence falls into the D.quinqueramus Zone (see Fig. 15). A. primus is found in-termittently to Core 503A-49, at a depth of approxi-mately 208 meters. We found a moderately well-pre-served flora at the base of Hole 5O3A that includes D.neorectus. D. neorectus was also found at about 185-190meters sub-bottom but is probably reworked. A down-ward decrease in abundance and preservation also char-acterizes this interval.Planktonic Foraminifers

Planktonic foraminifers are present in nearly all sam-ples but are rarely abundant because of carbonate disso-lution and dilution by siliceous microfossils. For thesereasons, examination of large samples (about 30 cc) ofcore catcher material was often necessary. Despite thisdifficulty, important zonal marker species are sufficient-ly abundant and well preserved to use a modified ver-sion of the foraminiferal zonation developed for theeastern equatorial Pacific (Jenkins and Orr, 1972). Asummary of the foraminiferal biostratigraphy is shownin Figures 15 and 18. A detailed discussion of the Neo-gene biostratigraphy, including the precise location ofspecific datums and zonal boundaries and the biogeog-raphy of planktonic foraminifers, is given in Keigwin(this volume).

The Pliocene/Pleistocene boundary at Site 503, asplaced by the first appearance of Globorotalia truncatu-linoides, is found between Samples 5O3A-7,CC and503A-9,CC in Hole 5O3A and in Sample 5O3B-8.CC inHole 503B. Jenkins and Orr (1972) defined the Pliocene/Pleistocene boundary by the last occurrence of Globi-gerinoides fistulosus, but we found this datum to be in-consistent and difficult to locate precisely. We place theearly/late Pliocene boundary at the last appearance ofgenus Sphaeroidinellopsis at Core Sample 503A-20-2,50 cm in Hole 5O3A and at 503B-19-2, 75 cm in Hole5O3B. Jenkins and Orr (1972), however, appear to definetheir early/late Pliocene boundary by the last occurrenceof Sphaeroidinellopsis subdehiscens (several meters lowerthan the last appearance of S. seminuliná). The last ap-pearance of Sphaeroidinellopsis at Site 503 is close tothe first appearance of G. fistulosus (Samples 5O3A-20-1, 100 cm; and 503B-19-1, 75 cm). Consequently, theearly/late Pliocene boundary is actually marked by twodatums.

The Miocene/Pliocene boundary at Site 503 is basedon the first appearance of Globorotalia tumida (Sample5O3A-37,CC), which has been shown to be a reliable

marker (Saito et al., 1975). The Miocene/Plioceneboundary at Site 83 is based on the boundary betweenthe nannofossil zones Ceratolithus rugosus and C. tri-corniculatus (Hays et al., 1972) and is about 30 metersshallower than the Miocene/Pliocene boundary definedby planktonic foraminifers at Site 503.

Several planktonic foraminiferal datums that may beuseful for subdividing the upper Miocene occur at Site503 (see Keigwin, this volume). The last appearance ofGloboquadrina dehiscens (Sample 5O3A-33,CC), whichis rare at Site 503, occurs near the Miocene/Plioceneboundary and is a useful marker for that boundary. Thegenus Pulleniatina first appears in Hole 503A, Sample5O3A-38,CC, preceded by an interval of sinistral Neo-globoquadrina acostaensis between about 187-191 me-ters. These datums appear more distinct and stratigraph-ically useful in the Pacific than they are in the Carib-bean. The last occurrence of Globigerinoides bulloideusfound in Panama Basin DSDP Sites 84 and 158 (Keig-win, 1976) occurs in Hole 5O3A in Sample 503A-40.CCat 169.90 meters sub-bottom. This extinction may pro-vide an important horizon for correlating Caribbeanand eastern equatorial Pacific sequences. The age ofbasal sediments is estimated to be about 8 m.y.

SilicoflagellatesNeogene silicoflagellates at Site 503 are especially

abundant and well preserved in Miocene Cores 5O3A-3Oto 54, but Pliocene assemblages in Cores 503A-12 to 30are less abundant and contain increased numbers of dis-solution-thinned specimens. A full description of the sil-icoflagellate Neogene zonation, evolution, and system-atics appears in Bukry (this volume). Here, we sum-marize the biostratigraphy, with emphasis on epoch andzonal boundaries.

The base of the Dictyocha stapedia Zone occurs inthe upper lower Pliocene at Sample 503A-19-2, 124-125cm. The base of the late Miocene-early Pliocene D.fibula Zone is defined by the Asperoid/Fibuloid rever-sal of Dictyocha. Unfortunately, the detailed countsmade possible by the HPC sediments reveal six reversalsof the Asperoid/Fibuloid ratio through the previouslydescribed interval of the D. fibula Zone. Hence the ratiois not a consistent criterion for the zonal boundary. Like-wise, the top of the D. brevispina Zone cannot be estab-lished because reversals of the Asperoid/Fibuloid ratioindicate that the D. fibula Zone occurs as deep as Core5O3A-54. The assemblages are diverse, and several newspecies are found (Bukry, this volume). The increaseddetail of the HPC record suggests that the upper Mio-cene zonation is not unique and that the Asperoid/Fibu-loid ratio is quite variable.

DiatomsDiatoms are rare and poorly preserved throughout

the Quaternary section at Site 503 (Cores 503A-1 through5O3A-8 and 5O3B-1 through 5O3B-8), common and wellpreserved in the Pliocene section (Cores 503A-9 through503A-32 and 503B-9 through 503B-26), and abundantand very well preserved in the upper Miocene section(Cores 5O3A-32 through 503A-54). The upper Miocene

175

SITE 503

Hole 503A Foraminifera Calcareous Diatoms Radiolaria Hole 503B_ _ _ _ _ _ _ _ _ _ _ Nannofossils and __^___^__^___

Silicoflagellates

è f ~ -I > | & s s * f * £! ; |s s ii 2 1 2 2 2 -|s i IQ < S S) o LU Events N Events ^ Events N Events N O S t/> < Q

5- E c 2 - J - (G. ocean ica) | 2 B l 5W/J^• — " - T P. acunosa •p • E

10- m _ S I I . 12P—o 73 100.91 _ 4 σ | ^ " ^ T M. elliptica . % A m

1 5 W — | ^ TN. reinholdii m— ° 97• 15

20 ~ M •» " § P)— 206 m "§ I. L neoheteroporos < p 6

25 • ^ | 1 " 1 « 25? 1 Trf,,/ oc,/ c TCmβc / n t yw/ ^ ^ L T R. praebβrgonii > T ft prismatium' η\

3 5 • i. 8 9 lf_β j I I i T f 1 • 35

4 0 . S 1 0 ^ / TD.broumri – | 1 0 40" VT G. mutticamerata « (D.brouweri) | — ]

1 1 / s Λ II , 45 _ ^ 8 ^ ^ g 1 1 45

"3 ^ T T. conve×a ^ δ —2.49— 12 .a " T D. pentaradiatus 4; I

50 ~ | — S T D • mrmπutriαa ' _ { D pentaradiatus) — • 2 " 4 ? "5°TD.surculus TS. peregrina ' : ^ H

55 — ^ \ " ~ ~ _ 5514 T ,~ / • * 1 \ T N. jouseae14 Tb.a/f/sp/ra _ T D. t a m a l i s ' ~ \ \ M

60 \ y& R. praebergonii — • 60Λ \ 1 r.H w

— \ Sphaeroidinellopsis \ HD65 16 \ ^ ^ ^ (D.surculus) — P ^ 2.91 . 6 5

_ B G. fistulosus' % 6lZ 3 1 8

70 1 7 * • ' 70r T A. doliolum. ' ' • _ __

BG. rwöer^ « ra ^ \ i d 7 5

80- & - T Ft. pseudoumbilica '•δ \ 19 •80„, S 1 S. penras fefras V

20 £ P. primal is ° ^85 _ | λ L R ^ | 2 0 8 5

21 ° \ ^\ Qc 2 1 **

90 — ^BS.dehiscens. > 1 ^3 . 8 6 9 022 \ 3 ~~l=_ \ S 22 °

95" N S _ 9523 I

ioo 2 4 ^ | .100— BD. asymmetricus . o. 24

1 0 5 . (C.rugosus) \ B P. prismatium «> — 1 Q 5

_ T C. acutus ^ ^ ~ 1 2 5

110 2 6 . § J A. primus g _^ T /V. cylindrica * | . ~~ 1 1 0

"~ 1 1 1 _27 S U

1 1 5 _ C3 BC. acufus N. jouseae 115120 " / / / / . ' 120

29125 — 125

"^ W/ T D quinqueramus " IT. miocenica!30 ~ ^ 130

3 1 β B G. twm/ctó —

Figure 15. Biostratigraphic summary of Site 503.

176

SITE 503

Hole 503A Foraminifera

Events

CalcareousNannofossils

Events

DiatomsandSilicoflagellates

Events

Radiolaria

Events

Hole 503B

§>««

135

140-

145

150-

155-

160-

165-

170-

175-

180

185^

190

195-1

200

2051

210

215-

220"

225

230

235

B P. primalis

~ T "D. navicula"

• B "D. navicula"

T N. miocenica

- T T. praeconve×a

S. berminghamipentas

N. acostaensis(Left coiling)

S. delmontensisperegrina

B A. primus

T 0. hughesi

T D. neorectus

135

140

145

150

155

160

165

170

175

180

185

190

195

-200

205

•210

215

220

225

230

235

T (for " top") indicates upper limits of ranges, and B (for "bot tom") lower limits. Substantial ranges of uncertainty (longer than the length of one core)are indicated in the "Events" columns by braces ( } ), and elsewhere by hachuring. Positions indicated on the left side of each " Event" column refer toHole 503A, and indications on the right side refer to Hole 503B.

Figure 15. (Continued).

177

SITE 503

interval is dominated by the genera Thalassionema andThalassiothrix. This group is the major diatom compo-nent in Holocene sediment that underlies the Peru-ChileCurrent (Burckle, personal communication). The abun-dance of this group in upper Miocene sediment may im-ply significant upwelling and productivity during thelate Miocene. A summary of the diatom biostratigraphyis shown in Figures 15 and 18. Here, we define only theepoch boundaries at Site 503. A detailed study of thediatom biostratigraphy, including the location of speciesdatums and zonal boundaries in Holes 503A and 5O3B,is given in Sancetta (this volume).

The Pliocene/Pleistocene boundary as defined byBurckle (1977) occurs between the last appearance ofRhizosolenia praebergonii Samples (503A-7-3, 48 cmand 503B-7-2, 40 cm) and the first occurrence of Pseu-doeunotia doliolus (503A-9-2, 102 cm and 5O3B-1O-1,40cm). The Miocene/Pliocene boundary as defined by Bur-ckle (1978) coincides with the last appearance of Thalas-siosira miocenica (Sample 5O3A-33,CC). Slight but con-sistent reworking (10% of stratigraphically useful spe-cies) appears in the lower Pleistocene, and significant re-working (up to 80% of stratigraphic markers) appearsin the lowermost Pliocene (Cores 503A-30 and 5O3A-31).The reworked flora in both intervals is composed of lateMiocene species.Radiolarians

Radiolarians are well preserved and common through-out the sediment from Holes 5O3A and 5O3B but are lesscommon and somewhat corroded in some samples fromCores 503A-4 to 503A-9 and 503B-6 to 5O3B-1O. Re-working of Miocene radiolarians occurs in Cores 5O3A-1 through 503A-29 and 5O3B-1 through 5O3B-13. Theamount of reworking is generally small but approaches20% in samples from Cores 503A-4, 5, 7, 10, and 11 and5O3B-3, 6, and 7. Reworked faunas represent more than50% of the assemblage in Cores 503A-7, 9, and 5O3B-8.

A summary of the radiolarian biostratigraphy isshown in Figures 15 and 18. Here, we present only theepoch boundaries at Site 503. A detailed summary ofthe Neogene radiolarian biostratigraphy, including thespecific location of radiolarian events and zones, is giv-en in Riedel and Westberg (this volume).

The top of the Pterocanium prismatium Zone, whichis considered to be approximately the Pliocene/Pleisto-cene boundary, is placed between Core Samples 5O3A-7-2, 50-54 cm, and 5O3A-7-3, 50-54 cm. This boundaryoccurs in the same interval in Hole 503 B. The PlioceneP. prismatium Zone occurs between Samples 5O3A-13-3,50-54 cm and 503A-7-3, 50-54 cm in Hole 503 A and be-tween 503B-14-2, 50-54 cm and 503B-7-3, 50-54 cm inHole 5O3B. The Pliocene Spongaster pentas Zone oc-curs between Samples 5O3A-31-2, 50-54 cm and 15-2,66-70 cm in Hole 5O3A and from the base of Hole 5O3Bto Sample 503B-14-2, 50-54 cm.

We place the Miocene/Pliocene boundary near theevolutionary transition from S. berminghami to S. pen-tas that takes place between Samples 5O3A-31-3, 50-54cm and 503A-34-2, 50-54 cm. Hole 5O3A penetrated thelate Miocene Didymocyrtis penultima Zone (Samples

503A-44-3, 50-54 cm to 503A-34-2, 50-54 cm) andreached the top of the D. antepenultimus Zone (Samples503A-54-3, 52-55 cm to 503A-48-2, 50-54 cm).

PALEOMAGNETISMThe paleomagnetic measurements at Site 503 fol-

lowed the procedure described in the paleomagneticsdiscussion of the Site 502 chapter (this volume). Eachcore was measured with the long-core spinner magne-tometer at 10-cm intervals, and one or more discretesamples were taken from each 1.5-meter section for mea-surement on the small-sample spinner magnetometer.

We encountered several problems at Site 503 thatdegraded the quality of the magnetic data. The mostserious problem is the presence of rust scale from thedrill pipe. The dark scales of rust are concentrated at thetop of each core but also are smeared inside the liner toseveral meters depth even in otherwise undisturbed por-tions of the core. The rust scale is highly magnetic andconsequently, when present, obscures the magnetic prop-erties of the sediment.

The rust scale is a serious problem in Hole 5O3A butless so in Hole 5O3B. Site 503 was deeper than 502, anddrill pipe was deployed that had not been used for sev-eral months. The relative contribution of the rust con-tamination to the magnetic measurements is accentu-ated at Site 503 because of remanent intensities of about40 (10 ~5) emu. Generally, long-core magnetic data fromat least the topmost 1.5-meter section of most corescould not be used because of the high noise level.

In contrast to these difficulties, various modifica-tions to the corer between Sites 502 and 503 greatly im-proved core-to-core orientation. There was also greaterattention to handling cores on deck to minimize relativerotation between core sections as well as disturbance ofthis less cohesive sediment. These improvements in partoffset the problem of the rust scale, particularly in Hole5O3B. The combination of long-core and discrete sam-ple measurements allows us to recognize the gross fea-tures of magnetostratigraphy to the middle of the Gil-bert Chron, approximately the top 100 meters of thesection. Sediment magnetism below approximately 130meters sub-bottom (near the Miocene/Pliocene bound-ary) becomes very weak and difficult to measure.

The depths of the magnetic reversals in the two holesare given in Table 5 and plotted with respect to thegeomagnetic polarity reversal timescale (modified fromMankinen and Dalrymple, 1979) in Figure 16. We ten-tatively identify most of the recognized paleomagneticchrons and subchrons to the Gauss Chron. We empha-size that many of the boundaries are based on discretesamples spaced 0.5 meter or more apart. Core recoveryis poor in the Gilbert Chron, and we have not been ableto refine the level of reversal boundaries in this interval.Magnetization of sediment below about 130 meters is soweak as to make the determination of a polarity stratig-raphy for the upper Miocene section almost impossible.

ACCUMULATION RATESWe used 12 horizons to generate sedimentation rate

and accumulation rate data for Site 503 (Table 6). These

178

SITE 503

Table 5. Location in each hole and the sub bottom depths of thepaleomagnetic boundaries found at Site 503.

PaleomagneticChrons and Subchrons

Bruπhes/ Matuyamatop of Jaramillobottom of Jaramillotop of Olduvaibottom of Olduvai

Matuyama/ Gausstop of Kaenabottom of Kaenatop of Mammothbottom of Mammoth

Gauss/ Gilberttop of Cochiti

Hole 5O3ASample

(interval in cm)

4 2, 100 120

9 2, 100 130a

12 2, 60 9014 3, 30 40

———

21A 3, 10 40a

Sub bottomDepth (cm)

12.17

35.1247.9557.15

88.65

_± 0.05

_± 0.15± 0.15± 0.05

—

± 1.15

Hole 5O3BSample

(interval in cm)

3 3, 60 70

4 2, 30 40b

7 3, 110 to 8 2, 20a

_12 2, 60 100

15 3, 80 10016 2, 75 14017 3, 80 10021 3, 25 45

Sub bottomDepth (cm)

10.82 ± 0.05

13.33 ± 0.0529.9 ± 0.90

_49.20 ± 0.10

63.55 ± 0.1066.84 ± 0.3072.51 ± 0.1089.70 ± 0.10

a The paleomagnetic record is not definitive at these levels.b Selection of this level assumes correct orientation between Cores 503B 7 and 503B 8.

horizons represent the eight best magnetostratigraphicboundaries, the three best dated biostratigraphic datumlevels, and an assumed zero age for the sediment/ waterinterface. The age and thickness of the 11 time intervalsbounded by these horizons is given in Table 6. The thick ness of each interval was computed in holes that containthe inclusive age boundaries so that differences in sub bottom depth between holes are eliminated.

A sedimentation rate for each interval was calculatedfrom the age versus depth relationship. Sedimentationrate is a function of both sediment influx at the timeof deposition and postdepositional compaction, so bulkaccumulation rates were calculated in order to removesome of the compaction effect. The calculated accumu

o

10

20

30

40

50

60

70

f 80

90

100

110

120

130

140

150

160 h

170

Age(10 6y. )Brunhes 1 Matuyama 2 Gauss 3

Quaternary1.5 cm/k.y.

1.3cm/k.y.

4 Gilbert. I i . .

I • IPliocene XCDO

2.0 cm/k.y.

2.6 cm/k.y.

2.7 cm/k.y.

3.5 cm/k.y.

1.5 cm/k.y.2.2 cm/k.y.

4.0 cm/k.y.

* ages corrected for latest decay constant

Figure 16. Age versus sub bottom depth for magnetostratigraphic boundaries at Site 503.

179

SITE 503

Table 6. Measured and calculated parameters used to determine sedimentation and accumulation rates.

Time Interval

1. 0 to Brunhes/ Matuyama

2. Brunhes/ Matuyama tobottom of Jaramillo

3. Bottom of Jaramillo totop of Olduvai

4. Top of Olduvai toG auss/ Matuyama

5. G auss/ Matuyama totop of Kaena

6. Top of Kaena tobottom of Mammoth

7. Bottom of Mammoth toGauss/ Gilbert

8. Gauss/ Gilbert totop of Cochiti

9. Top of Cochiti toLAD T. miocenica

10. LAD T. miocenica toLAD T. praeconvexa

11. LAD T. praeconvexa toFAD A. primus

Age(m.y.)

0 0.73

0.73 0.98

0.98 1.66

1.66 2.48

2.48 2.92

2.92 3.18

3.18 3.40

3.40 3.86

3.86 5.0

5.0 5.7

5.7 6.5

Deptha

(m)

0 70 10.87 13.5

10.8 13.313.5 713.3 29.9

7 48.029.9 49.148.0 57.149.1 63.657.1 763.6 66.8

?66.8 72.5

7 88.672.5 89.888.6 127.089.8 7127 160

?160 208

?

M eanThickness*5

(m)

10,8

2.516.6

19.2

11.8

3.2

5.7

16.9

38.4

33

48

SedimentationRate

(cm/ k.y.)

1.5

1.02.4

2.3

2.7

1.2

2.6

3 7

3.4

4,7

6.0

Mean δJ•g/ cm^

1.41.4

:

.35

.30

.3

.3,3.3.3.35.3.4,3.3.3.35.4

—1.4_1.3—

W.C.%

7172_80737479807878—72—75757671

65_66—

Mean δ d

g/ cm^

0.80

0.70

0.75

0.70

0.70

0.80

0.70

0.75

0.80

0.85

0.80

BulkAccumulation

Ratee

(g/ cm2/ k.y.)

1.20

0.70

1.80

1.60

1.90

1.00

1.80

2.80

2.70

4,00

4.80

MeanCaCO3

(%)

54—35—43—33—34—44——3535—46_53

53—

Accumulation Rate*"CaCO3

(g/ cm2/ k.y.)

0.65

0.24

0.77

0.53

0.65

0.44

0.63

0.98

1.24

2.10

2.54

Non CaCθ3(g/ cm / k.y.)

0.55

0.46

1.03

1.07

1.25

0.56

1.17

1.82

1.46

1.90

2.26

* Depths for each time interval for Holes 5O3A and 5O3B." Mean thickness computed using boundaries of a time interval recovered in either hole.c Wet bulk density from GRAPE data.d Calculated dry bulk density: δ<j = δw/ ( l + we).c Bulk accumulation rate = sedimentation rate × δ j.* Accumulation rate of carbonate = bulk accumulation rate × % carbonate; non-carbonate rate = bulk - carbonate rate.

LAD = last occurrence datumFAD = first occurrence datum

lation rate provides a better approximation of sedimentinflux rate, particularly in older, more compacted sedi-ment (van Andel and others, 1975).

Sedimentation rates at Site 503 range from 1.0 to 6.0cm/k.y., with an average of 2.9 cm/k.y. We found thehighest sedimentation rates in the upper Miocene andlower Pliocene sections and the lowest rates in the Pleis-tocene sequence. A short interval in the mid-Pliocene ischaracterized by low sedimentation rates. Because onlyslight changes in age or thickness will result in variationsof the same order of magnitude, fluctuations about thistrend may be due to the resolution of the time scale.

The wet-bulk density (GRAPE) and water contentdata were used to calculate bulk accumulation rates foreach time interval used in the sedimentation rate curve(Table 6). Trends in bulk accumulation rates (Fig. 17)decrease throughout the section, with highest values inthe upper Miocene and a sharp decrease in the mid-Plio-cene similar to the trend of sedimentation rates. The de-crease in rates is consistent with the trends for the equa-torial Pacific (van Andel and others, 1975) and may bedue to several factors, including reduction of sedimentinflux from terrigenous sources, decreased biogenic pro-ductivity, and reduced carbonate preservation. In orderto distinguish among these components the carbonateand noncarbonate accumulation rates were calculatedfrom bulk density and average carbonate content (Table6 and Fig. 16). Carbonate accumulation rates decreasethrough the section, with highest rates in the upper Mio-cene and lower Pliocene interval (>4 m.y.) and lowestin the Pleistocene sequence. The trend is consistent withthe equatorial Pacific pattern shown by van Andel andothers (1975). The mid-Pliocene and Quaternary (4 Mato Holocene) are characterized by a uniformly low car-

bonate accumulation rate, with values less than 1.0g/cm2/k.y. The decrease in carbonate accumulation ratesin this interval may reflect the deepening of the site asthe plate moved from the spreading center.

Noncarbonate accumulation rates also decreasethroughout the section. The decrease in noncarbonaterates throughout the equatorial Pacific (van Andel andothers, 1975) may be due to a reduction in the siliceousbiogenic component (see Sancetta, this volume) ratherthan to a reduction in the influx of terrigenous material(see Rea, this volume).

SUMMARY AND CONCLUSIONSOur objective at Site 503 was to recover an undis-

turbed, complete upper Neogene and Quaternary sec-tion using the Hydraulic Piston Corer (HPC). Our ma-jor objective was met by coring two holes to a totaldepth of 235.0 meters sub-bottom, and we recovered areasonably complete section that represents approxi-mately the past 8 m.y. We recovered 58.8% of the coredinterval in Hole 503A and 83.5% in Hole 5O3B, withabout 81% and 86%, respectively, of the sediment un-disturbed. After modifications to the core catcher andshear pins, the HPC performed well. The value of theHPC in obtaining undisturbed sediment can be appreci-ated when Site 503 is compared to Site 83 (see Frontis-piece, this volume). A summary of recovery, lithology,Paleomagnetism, biostratigraphy, and bulk accumula-tion rate is given in Figure 18.

Hays et al. (1972) indicated that Site 83 was on theeast flank of the East Pacific Rise. However, total fieldmagnetometer data recorded on our approach to anddeparture from Site 503 indicate that both Site 503 and83 are actually located on the north flank of Galapagos

180

SITE 503

I 2

Quaternary Pliocene Miocene1 3 4

Age (m.y.)

Figure 17. Plots of bulk, carbonate, and noncarbonate accumulation rates (g/cm2/103y.) versus time forSite 503. The data points are midpoints of each time interval from Table 6.

Ridge, not the east flank of East Pacific Rise (see Gard-ner^ Underway Geophysics, this volume).

The section at Site 503 is rather uniform and is com-posed of pelagic sediment with only minor composition-al changes. Cycles of carbonate and color changes areapparent throughout the entire section, with periodici-ties on the order of 40 k.y. per cycle. Curiously, very lit-tle volcanic glass and no zeolites were found. The sedi-ment changes from an oxidized to a reduced oxidationstate at 8.45 meters and is reduced throughout the re-mainder of the section. The lack of sediment distur-bance is illustrated by open burrows that occur from 9.3to 64.0 meters sub-bottom. Nodules formed of rhodo-chrosite around burrows occur from 13.5 to 235 metersand are common from 13.5 to 50 meters. Clay contentremains fairly constant at low percentages from 0 to 226meters but then abruptly increases to greater than 25%.This increase occurs within 10 meters of the oceanicbasement and may be caused by an increase of clay pro-duced by seafloor weathering of the basement.

Detailed measurements of shear strength, sonic ve-locity, bulk density, water content, porosity, and cohe-sion show that the entire section is undercompacted.Shear strengths average about 400 g/cm2 from 15 toabout 210 meters. Although similar values were obtainedat 25 meters depth at Site 502, they increased withdepth. The maximum value of shear strength at Site 503is only 1686 g/cm2 and occurred below 210 meters.Porosities are approximately 90%, and water contentsare about 80% down to a depth of 210 meters. Sonic

velocities average 1.510 km/s down to a depth of 210meters. The change in all physical properties at about210 meters may indicate a "collapse" of the section atthis level. One explanation may be that the siliceousmicrofossils, especially radiolarians, hold the sedimentin a highly porous state until some threshold lithostaticload is applied. The section collapsed at loads above thethreshold and became less porous, which results in highervelocities and shear strengths and lower water contents.

The sediment contains microfossil assemblages thatrange in age from Quaternary through the latter part ofthe late Miocene. Calcareous and siliceous microfossilsare sufficiently numerous and well preserved for detailedstratigraphic interpretation. Cyclic zones of carbonatedissolution appear to occur throughout the sequence.Reworked assemblages of nannofossils and a monospe-cific diatom assemblage appears in the late Miocene.Radiolarians and diatoms are poorly preserved in Qua-ternary sediment, but preservation is good in the Ter-tiary section.

We were able to identify most magnetostratigráphicchrons and subchróns above the Gauss/Gilbert bound-ary, even though rust contamination was a serious prob-lem, especially in Hole 5O3A. Most magnetostratigráph-ic datums are located to the nearest meter, becausediscrete sample measurements were needed to avoid rustcontamination. We observed distinct cycles of NRM in-tensity with wavelengths comparable to the carbonatecycles. This covariance implies a direct correlation of in-tensity with lithology. Unfortunately, the rust problem

181

Biostratigraphic Zones

503A 503BLITH.UNITS MAGNETICS AGE

150

200

Indicates no recovery

HO< O

PLANKTONICFORAMINIFERS

Pulleniatinaobliquiloculata

Globigerinoidesfistulosus

Sphaeroidinelladehiscens

Globorotaliaturn id a

Globorotaliaplesiotumida

CALCAREOUSNANNOFOSSILS

Emiliani hu×leyiGephyrocapsa oceanica |Ps udoemiliania lacunosaHelicopontosphaerasellii |Cyclococcolithus macintyrei

Discoaster brouweri

Discoaster pentaradiatusDiscoaster surculus |~

Discoaster tarn al is

Reticulofenestra pseudoumbilica/Discoaster asymmetricus

I Cerotolithus rugosa

Ceratolithus acutus

Amaurolithus primus

Discoaster berggreni

RADIOLARIA

Lamprocyrtisheteroporos

Pterocaniumprismatium

Spongaster pentas

Ommatartuspenultimus

Ommatartusan tepenultimus

DIATOMS

Pseudoeunotiadoliolus

Rhizosoleniapraebergonii

Nitzschia jouseae

Thalassiosiracon vex a

Nitzschiamiocenica

Nitzchia porteri

AGE

Bulk Accumulation Rate(g/cm2/k.y.)

and Sedimentation Rate(cm/k.y.)

1 2 3 4 5 6' I

1.0

2.0 bulk ace. rate

3.0

4 . 0

5.0

6.0

7 .0

Figure 18. Summary of the recovery, lithostratigraphy, magnetostratigraphy, biostratigraphy, and sediment accumulation rates for Site 503.

SITE 503

obscures many of paleomagnetic trends, but a decreasein the NRM intensity does occur during the lower Gil bert Chron.

Bulk accumulation rates at Site 503 steadily decreasefrom late Miocene (4.0 g/ cmVk.y.) to late Quaternary(1.2 g/ cm2/ k.y.) with a distinct interval of low ac cumulation rates (1.2 1.6 g/ cm2/ k.y.) in the mid Plio cene. The rate of both carbonate and noncarbonate ac cumulation mimics the trend of bulk accumulation, andnoncarbonate components (silica and clay) generally re flect the carbonate pattern.

REFERENCES

Boyce, R. E., 1976. Definitions and laboratory techniques of com pressional sound velocity parameters and wet water content, wet bulk density, and porosity parameters by gravimetric and gammaray attenuation techniques. In Schlanger, S. O., Jackson, E. D ., etal., Init. Repts. DSDP, 33: Washington (U .S. G ovt. Printing Of fice), 931 958.

, 1977. Deep Sea Drilling Project procedures for shear strengthmeasurement of clayey sediment using modified Wykeham andF arrance laboratory vane apparatus. In Barker, P. F ., Dalziel, I .W. D ., et al., Init. Repts. DSDP, 36: Washington (U .S. G ovt. Print ing Office), 1059 1068.

Burckle, L. H ., 1977. Pliocene and Pleistocene diatom datum levelsfrom the equatorial Pacific. Quat. Res., 7:330 340.

, 1978. Early Miocene to Pliocene diatom datum levels forthe equatorial Pacific. Spec. Publ. Geol. Res. and Develop. Centre,Republic of Indonesia, pp. 25 44.

G artner, S., 1977. Calcareous nannofossil biostratigraphy and revisedzonation of the Pleistocene. Mar. Micropaleontol., 2:1 25.

H ays, J. D ., et al., 1972. Init. Repts. DSDP, 9: Washington (U .S.G ovt. Printing Office).

Jenkins, G . D ., and Orr, W. N ., 1972. Planktonic foraminiferal bio stratigraphy of the eastern equatorial Pacific, Leg 9. In Hays et al.,Init. Repts. DSDP, 9: Washington (U .S. G ovt. Printing Office),1059 1205.

Keigwin, L. D ., Jr., 1976. Late Cenozoic planktonic foraminiferalbiostratigraphy and paleoceanography of the Panama Basin. Micro paleontology, 22:419 442.

Mankinen, E. A., and Dalrymple, G . B., 1979. Revised geomagnetictimescale for interval 0 5 m.y.B.P. J. Geophys. Res., 84:615 626.

Saito, T., Burckle, L. H ., and H ays, J. D ., 1975. Late Miocene toPleistocene biostratigraphy of equatorial Pacific sediments. LateNeogene Epoch Boundaries: Micropaleontol. Spec. Publ. 1: NewYork (Micropaleontology Press), 226 244.

van Andel, Tj. H ., H eath, G . R., and Moore, T. C , Jr., 1975. Ceno zoic history and paleoceanography of the central equatorial PacificOcean. Geol. Soc. Am. Mem. 143.

APPENDIX

Table 3. Smear slide summary of major and minor lithologies for Site 503. The estimates are qualitative, using < 5 % estimate = rare, 5 25%= common, 25 75% = abundant, and > 7 5 % = dominent.

SMEAR SLIDE SUMMARY: Dominant Lithology HOLEJ>03_

TRACE< 5 % RARE

5 2 5 % COM M ON2 5 7 5 % ABUNDANT

> 75% DOM INANT

SAMPLEINTERVAL

i I2 S α><S £ I1 1,42

1 1,801 2,751 3,100

BIOGENIC COMPONENTS

Fora

ms

I:

Nann

ofos

sils

1

Radi

olar

ians

Diat

oms

Ii

Spon

geSp

icules

Fish

Deb

ris

Silic

o fla

gella

tes

NON BIOGENIC COMPONENTS

Quar

tz

Felds

pars

Heav

yM

inera

lsLig

htGl

ass

ttII

Dark

Glas

s

Glau

coni

te

i

Clay

Mine

rals

1

Othe

r(s

pecif

y)

AUTHIGENIC COMPONENTS

Palag

onite

Zeol

ites

Amor

phou

sIro

n Ox

ides

Fe/M

n M

icro

Nodu

les

TI1Py

rite

4jT

Recr

ysta

l.Si

lica

jCa

rbon

ate

(uns

pecif

ied)

ICa

rbon

ate

Rhom

bsOt

her

(spe

cify)

183

SITE 503

Table 3. (Continued).TRACE t

< 5 % RARE5 2 5 % COMMON

SMEAR SLIDE SUMMARY: Dominant Lithology M n , p 503A 2 5 " 7 5 % A B U N D A N T

π U U C >75% DOMINANT

Table 3. (Continued).TRACE t

<5% RARE5-25% COMMON

SMEAR SLIDE SUMMARY: Dominant Lithology wni P 503A 25"75% A B U N D A N TM U L t >75% DOMINANT

SITE 503

TRACE t<5% RARE

5-25% COMMONSMEAR SLIDE SUMMARY: Minor Lithology H O L E 5 0 3 A 25-75% ABUNDANT

>75% DOMINANT

SITE 503

Table 3. (Continued).

TRACE t<5% RARE

5-25% COMMON

SMEAR SLIDE SUMMARY: Dominant Lithology H n | P 503B 2 5 " 7 5 % ABUNDANTm J I - t >75% DOMINANT | |

SITE 503

Table 3. (Continued).

TRACE t< 5 % RARE

5 2 5 % COM M ON

SMEAR SLIDE SUMMARY: Minor Lithology HΠ I F 503B 2 5 " 7 5 % A B U N D A N T

M U L t >75% DOMINANT

SITE 503 HOLE CORE (HPC) 1 CORED INTERVAL 0.0-4.4 r

Xi i

IME L

ts3

u

ATIC

ZCN

JE

BIO

3ü j

J(F

)

••

nica

(r

8o

FOSS LCHARAC

s

|

CP

(Λ

SS

2

CM

CM

1

TER

I

CG

SF

ri

o

o

o

4.5

8*r

4.69

z

CTI

O

<Λ

2

3

4CC

CA

rε

•

0.5 —

_

__

_

_

GRAPH CLITHOLOGY

I _ _ _r _r _

_ _ _ _ _ :' _ _ _ _ ;

—_"_ J

—jr^ r T

111 j 111111111

1 1

1 1

11

II

II

11

II

II

ill 111 1 ill

/ _ t

:

Q.

:

\_r= =

= =

s =

ür-ü^'-

/^-±

J ^

z

is-I 32 Q

F^

/ )

K S S

-–

•

•

LITHOLOGIC DESCRIPTION

5YR 2/2Cyclic alternation of IRON OXIDE-BEARING SILICEOUS NANNO

10YR 5/4 MARL, which is dark reddish brown (5YR 2.5/2) in color; CALCARE•H)YR 6/4 0 U S C I - A Y • w π i c h i s d a r k VβHowis" brown (10YR 4/4) in color; and

— SILICEOUS CALCAREOUS MARL, which is light yellowish brown(10YR 6/4) in color. Burrowing and mottling is abundant. The sedi ment types alternate dowπcore with common gradation between

5YR 2.5/2 endtypes in color and composition.

SMEAR SLIDE SUM M ARY1 42 1 80 2 75 3 100D D D D

Pyrite 1/T Clay minerals 25/ A 15/C 67/ A 49/ AVolcanic glass (It) 15/C Zeolites 1/TMicroπodules 10/CCarbonate unspec. 5/C 10/C 2/R 5/C

1 0 YR4 / 4 Foraminifers 15/C 5/C 5/CCalcareous nannofossils 25/ A 5/C 5/C 15/CDiatoms 10/C 10/C 10/C 10/CRadiolarians 5/C 5/C 5/C 57CSponge spicules 10/C 10/C 10/C 10/CFe oxides 5/C

Smectite 50%Illite 14%

5YR 3/4 Chlorite & 10YR5/ 6 Kaolinite 36%

_5 YR3 / 4 CARBON CARBONATE: 1,CC% Carbonate 39

10YR4/ 4 % Organic carbon 0.3

SYR 3/4

10YR4/ 4

~IOYR 6/4

~10YR 4/410YR6/ 4

7.5YR 4/4

SITE 503 HOLE A CORE (HPC) 1 CORED INTERVAL 0 . 0 1 . 81


5YR 3/3

5YR 3/3 to10YR 6/6

10YR4/ 4

5YR 3/3

Cycles icolor fπ6/61. Bu

SMEAR

Clay mirVolcanicCarbonaForaminCalcareoDiatomsRadiolarSoonαe!

Df CALCAREOUS BEARING SILICEOUS OOZE ranging inDm dark reddish brownrrowing and mott ling are

SLIDE SUM M ARY1 80D

lerals 50/ A: glass (It)te unspec. —ifers 10/Cus nannofossils 10/C

15/Cians 5/Cioicules 10/C

(5YR 3/3) to brownish yellow (10YR: common.

1 145D45/ A10/C10/C

5/C10/C5/C10/C

CARBONATE BOMB;

29 c 39% 49 c 59 c 64 c

n = 66%= 64%n 7 4 %Ti 7 0 %•n = 78%

1 1 1 1

.

0 919293 94 9

m • 43%m = 36%

:m 37%: m 3 1 %:m 34%

CLAY MINERALOGY (<2 m): 1 71 c

CARBON CARBONATE: 1.CC

SITE 503 HOLE A CORE (HPC) 2 CORED INTERVAL 1.8-6.2 m SITE 503 HOLE A CORE (HPC) 3 CORED INTERVAL 6.2-10.6 m

0 0


: Graphic lithology represents avera• slides and does not reflect the del

:ional changes between smetual lithologic trends. Color

Cycle alternation of CALCAREOUS AND MICRONODULE•BEARINGSILICEOUS OOZE, which is dark grayish brown (10YR 3/2) in color,and SILICEOUS MARL, which is white (5Y 8/2) and light olive gray(5Y 6/2) in color. Gradations between endtypes in color and composi•

lSeci the t of the

10YR 4/3

5Y 8/2, 6/210YR4/3

10YR 3/2

10YR 4/3

SMEAR SLIDE SUMMARY

Amorphous iron oxicClay mineralsVolcanic glass (It)MicronodulesCarbonate uspec.ForaminifersCalcareous nannofosiDiatomsRadiolarians

1-80D

le28/A_15/C10/C_

àls 4/R15/C25/A

1-130D-30/A5/C_10/C3/R20/C15/C7/C

CC, 10D5/C35/A_-3/R7/C25/A10/C5/C

I/T 5/C 5/C2/R 5/C 5/C

CARBONATE BOMB:OYR 3/2

10YR 3/2,10YR 4/3

-59 = 58%-69 cm-79 cm-89 cm-99 cm-109 err-119 err-129 err-139 err•149 err

2-9 cm -

= 37%- 3 6 %»53%- 6 3 %

- 56%- 5 3 %- 6 1 %- 2 9 %= 32%

42%

CARBON-CARBONATE% Carbonate% Organ c carbon

2-19 cm2-29 cm2-39 cm2-49 cm2-59 cm2-69 cm2-79 cm2-89 cm2-99 cm2-109 c2-119c

2, CC77

0.1

= 53%= 49%= 69%= 70%- 3 9 %- 50%= 48%- 4 6 %- 4 0 %

n - 42%n » 4 1 %

2-1292-1392-1493-193-293-393-493-593-693-99


;red. (Biostratigraphy based upon mud streaked c

CARBON-CARBONATE: 3, CC% Carbonate 57% Organic carbon 0.2

SITE 503 HOLE A CORE (HPC) 4 CORED INTERVAL 10.6-15.0 r

f 2

TIM

E

£

ë

oI

ATI

GR

/ZO

NEBI

OST

R

! _

5; z~ aH °

|

1

I I1 §,

f'a.'5

ihol

dii [

V (N) <

1

Small

(D)

' I2.

1

I

CP

FOSS LCHARACTER

%

zz

FM

FM

CM

FM

FM

1

5

C G

FM

RP

|

FG

.a

' α

• s

11TFG

FG

dii

rein

hol

FG

1ε

I<FM

1 .

S.i

ito10.

oCO

o

•

2.52

14.0

1 13

.8!

CTI

ON

1

2

3

4

ETER

S

S

0.5 —

__

_

GRAPHICL THOLOGY

VOID" ~~ T

HT I

r

u / "

= ( ^

)\ _r1 .

l '

VOID

_r_

ri:

1 3 I ~

—I: z

~ I

— 1 'J _ l _ •i — . I

1 —*~_ 1 _

1 •

1

J — . •

1

VOID jr. I~Z

• JT

r_r _

>

~ L

j _ .

['11

oQooo

[STR

UCT!

iT.

9 «

–

1

#


Cyclic alternation of NANNO RADIOLARIAN OOZE, which is darkgreenish gray (5G 6/1 and 5G 5/1) in color, and SILICEOUS M ARL,which is light greenish gray (5G 8/1) in color. The sediment is burrowedand mott led with some areas of pyrite enrichment (Smear Slide 2 100

5G6/ 1 and 3 31).& SMEAR SLIDE SUM M ARY5G 5/ 1 1 60 2 100 3 20 3 31

D M D M— Pvrite 10/C 1/T 10/C

Clay minerals 30/ A 20/C 21/C 22/ CVolcanic glass (It) 5/C 3/R 4/R Carbonate uπspec. 8/C 15/C 20/C 10/ CForaminifers 2/R 3/R 10/C 3/RCalcareous nannofossils 20/C 7/C 15/C 20/ CDiatoms 5/C 5/C 10/C 10/CRadiolarians 30/ A 20/C 15/C 20/ CSponge spicules — 2/R Fish debris 5/C 5/C

CARBONATE BOMB:1 19 c m 3 9 % 2 99 cm = 1 7 % 3 49 cm = 37%

5 G4 / 1 1 29 c m 4 5 % 2 109 c m 4 0 % 3 59 cm = 27%& 1 39 cm = 49% 2 119 c m 4 5 % 3 69 cm = 48%5 G6 / 1 1 49 cm = 37% 2 129 cm = 39% 3 79 cm = 63%

~ 1 59 cm = 20% 2 139 cm = 4 1 % 3 89 cm 65%1 69cm = 28% 2 1 4 9 c m 5 6 % 3 1 1 9 c m 6 2 %2 29 c m 2 9 % 3 9 cm = 67% 3 129 cm = 57%2 39 cm = 32% 3 19cm = 62% 3 139 cm = 54%2 49 cm = 2 1 % 3 29cm = 5 1 % 3 149 cm = 62%

_ 6G 3/1 2 59 cm = 17% 3 39 cm = 35%

5 G4 / 1 , CLAY M INERALOGY ( < 2 m ) : 2 121 cm5G 6/ 1,8, Smectite 93%5G 8/1 C m o r i , e &

Kaolinite 7%

5 G 8 / 1 CARBON CARBONATE: 4, CC~ 6 G2 / 1 t o % Carbonate 50—5G8/ 1 % Organic carbon 0.3

5G4/ 1

_5G8/ 1

5G 8/1 with5G 6/1

> > SITE 503 H 0 L E A CORE (HPC) 5 CORED INTERVAL 15.0 19.4 m SITE 503 HOLE A CORE (HPC) 7 CORED INTERVAL 23.8 28.2 m GO

)S, T i T FOSSIL 1 T FOSSIL HC5 * £ CHARACTER * £ CHARACTER t f l

g 5 u | « | c | 1 2 „ g 2 » | «; 1 g I I z </> ,. IΛ

T^ | § l i l „ ° ë 5 1 ^HoloGY ] H LITHOLOβlC DESCRIPTION ? | | g | § | ^ 1 _ P | LS S I S S GV „ | | | „ LITHOLOGIC DEiCRIPTION

lD fN I 1 H ° i * ^ t i l l i i 3 f e N I i ^ I § | 8 ^ 3 i i | I

I 1 1 1 1 ü f i l l I "~ I 1 1 1 i si i i i l su> £rvtr- ~> _ i _ " - r - - C Λ J L O Cyclic alternation of SILICEOUS MARL, light greenish gray (5G 8/1),

_r_ _ : f l . • 5G8/ 1 Cyclic alternation of SILICEOUS MARL, which is light greenish gray _ _ _ = Q _ | _ Q in color, and CALCAREOUS BEARING SILICEOUS OOZE, olive (5Y Hhrt: O"l ' 5 G 8 / " i n c o l o r • a n d C A L C A R E O U S SILICEOUS OOZE, which is ~JTjT. ^ : j _ . O 4/3) and light olive gray (5Y 6/2) in color. Gradations between the end _ Tir~s~— J~ | — 1 — dark greenish gray (5G 4/1) in color. Gradations between endmembers _ —J~— z^• , —*— x types in color and composition are common. Beds enriched in pyrite,

CM F P _ — _ _ " : K . L . in color and composition are common. Mottling and burrowing are F G o g _ _ T ^ _ 1 O grayish black (N2) in color, are at 0 3 cm in Section 2 and 73 76 cm

çc r z H M ^ «L_ * common. Black (N2) burrows and rones enriched in pyrite arecommon. FM CM • ---^r~^^-L^ Q in Section 3, A large mottle with concentric millimeter rings enriched| " ü - I -C - =( •*"_!_ * * 5G4/1 β" ~~ ~ rλ• H I O in pyrite is at 72 90 cm in Section 2. The sediment is highly mottled| 1 " ^Hr 3 "v i — , SMEAR SLIDE SUMMARY 3 1 § β n d b u r r o w β d •• ~ ~ ~ " j • I 5BG7/2 1 " 5 6 1 9 β 2 " 3 0 M 3 2 7

"* U I _r { ^ J _ J " _ D M D D M VOID SMEAR SLIDE SUMMARY_ : — _ J , A. ^ 5G2/1 Pyrite 2/R 15/C 30/A 2 113 3 40 3 5

_ _ ^_ _ v _, . t o Clay minerals 35/A 35/A 30/A 30/A 10/C _ RP S ' _ ^ ^ _ _ _ _ _ ^ D D DS C M

R P " l ~ . > • J j , – _5Y5/ 1 Volcanic glass (It) 1/T 2/R 5 3" " ^ F r n Clay minerals 27/A 30/A 17/C a ~ ~ H : = ( • 5Y6/2 Carbonate unspec. 15/C 20/C 20/C 30/A 10/C § N " > _ _ " v J _ . ^ Volcanic glass (It) 3/R H& h^HJ^jJ* " — Foraminifers B/C 2/R 5/C 4/R K B >" £ !=• = j_ « J t Volcanic glass (dk) 4/R1 8 _" _ _ _ _ ' L L 5G6/1 Calcareous nannofossils 10/C 15/C 20/C 4/R 1 ^ . _£_ _ =Q= _1_ Carbonate unspec. 10/C 10/C 30/A

– f • è 5 •-"-I-C? • 1 - Diatoms 10/C 10/C 10/C 16/C 10/C 5 ~ J T = = - l _ " ~ N2 Foraminifers 8/C 2/R 3/R| f " - 1-1-5 O -L. - – - Radiolarians 15/C 3/R 10/C 20/C 20/C " _ --_"_: _ri_ J - • _ Calcareous nannofossils 25/A 5/C 6/CS= "Sirzr —>. —*—_,_ 5 G 8 / 1 Sponge spicules 2/R . H H r ^ - t - - 5G 7/1 Diatoms 10/C 20/C 16/CS',1 " - I - X ^ ' - 1 — Fish debris 2/R - g . =^=-F^~1 — " – Radiolarians 10/C 20/C 20/C

F M - - I - I - I - =C-L. * Silicoflagellates 5/C - 5/C 5/C 3/R jri _ - ^ V O J D _ Sponge spicules 5/C 5/C 1/T£ - - ~ - ~ - " O_ _ ! _ - * - - – - Carbonaceous material 5/C „ . - • • | ' - ^ VOID Silicoflagellates 2/R 8/C 4/R

1 ~ H ~ JS-1-, * " 5 G 6 / 1 CARBONATE BOMB: - - " _ - ^ 3 > C - ! - " ! " . - - ~ CARBONATE BOMB:£• | " I I I [>α. 1 9 cm 77% 1 139cm 37% 2 119 cm = 46% fe ^ I~I Λ • 5 G 1 19 cm = 43% 2 139 cm = 35%E I 2 H I — =(_!_""" – 1 19 cm 78% 1 149 cm 47% 2 129 cm 32% E | ^ 2 . ~ • u . J ~N2rinαson 1 49 cm 38% 3 19 cm = 20%S | : _ _" n _ J 6 G 8 / 1 1 29 cm 69% 2 9cm 36% 2 139cm=18% S | | f ~_ _ = = j _ • 9 1 139cm = 31% 3 49cm 7%1 °• R P I I : ^ _L 1 39 cm 49% 2 19 cm 63% 2 149 cm 22% = | j O i " ~ 2 19 cm = 63% 3 79 cm 30%° ~~ I I r • C• L 1 49 cm 54% 2 29 cm = 67% 3 9 cm =13% t i t _ _ _ j _ _ J 5 G 7 / 1 2 49 cm 49% 3 109 cm = 14%

> _ ! > r I 5 Q 6 / , 1 59 cm = 35% 2 39 cm = 61% 3 19 cm =16% S _ : _ _ " l _ . _ 2 79 cm 45% 3 139 cm 19%ü Z- I - I - = C l - . 1-69 cm = 30% 2-49 cm = 54% 3-29 cm - 33% 1 B - - _ - - ^ – _ l _ . 2-109 cm-43%1 CM " - I - I - I L > 1 _ - – - 1-79 cm = 47% 2-59 cm - 45% 3-39 cm = 57% ™ % " ! " " - _ : r = j l °G S /

I -h~ . - r , -» • 1-89 cm = 62% 2-69 cm = 46% 3-49 cm = 51% •i " r l I - O •1- . • _ CARBON-CARBONATE: 7, CC•* - - - - - - - - < - C " - 1 - 5G4/1 1-99 cm-68% 2-79 cm 62% 3-59 cm-29% „ " IHH : = = 1_ . B G 6 / 1 % Carbonate 40— P. Hrr-ld-LJ. 1-109 cm-65% 2-89 cm = 62% 3-69 cm = 56% 3 ™ - - ~ - _r\. . - 1 - to % Organic carbon 0.3

2 __-_-_-T ~ ^ 1 - * 1•119cm-59% 2-99cm = 62% 3-79 cm = 62% ~ " _ - ~ - ^ - ~V _ 1 _ ' 5 ^ _ 5Y 4/1~ £HHI ^ " * " 1-129 cm = 54% 2-109 cm = 47% § ErEH: = = J ~ I '" I-I-2- ^ - L = rN2 f— - I - I - ~^~i- i 5Y 6/2,- r-_T-^ O_ ~_L CLAY MINERALOGY (<2µml: 2-71 cm : ; 5 ~\r- - - i-i 5Y 4/3- -I-I-I- "O - j . 5 G 6 / 1 & S m e c t i t θ 9 6 % 1 1 R M FM b I a < > L r • . * N2,and

I CM FM _ r 2 Z i ; ^ – _, _ _5G8/ 1 Chlorite & | | RP y H H ^ a J L* ^ 5G 4/1

3 3 I I r 2 V j r " —_i 5G4/1 Kaolinite 4% J8 ^ _ _ ^ L.

j : " r lHrp y C" ~ L 5G8/1 CARBON CARBONATE: 5, CC * ü 3 " ZT--£. = = * - j _ = N2

»" _ % Organic carbon 0.4 - ryj? 2 ^ _->-_ 5 Y β / 2

VOID _ _: _~X" J " «o ~6Y4/ 3," =—1 rr— n " f ™ I ~ I = s . " 1 N2,and

CP FP FM g CC " I I _^ V ~J1 O 6 G 6 / 1 § ' I I ~^~ ~ I *

SITE 503 HOLE A CORE (HPC) 6 CORED INTERVAL 19.4 23.8 m °" F p " ^ Cc[ [ i l ^ j F , 5 ^ • ~l I | f~5Y6/2andN2

FOSSIL ™J CHARACTER I I I I , I I ^ I

% 2 l l s l 1 z «T i P l ^ i I _ P r LfTHOPLθ§Y ^ < S L.THOLOGIC DESCRIPTION SITE 503 HOLE A CORE (HPC) 8 CORED INTERVAL 28.2 32.6 m

a= «N I * 5 ! t i » 5 i l l ? IS FOSSIL! j ; < ! S 0 J 1 " ^ S E M Ö I E CHARACTER

" I £ 11 i ll iül i 1 1 -hig 1 1 z "t l ^ ~ ^ ~ Z -"-I =T<>VF1- " ~ ~ Ti p i I I 1 , 1 I S S v -111 LITHOLOGiCDESCR.PTiON

t ' ^ "-*—~-—^—^ '—J No core recovered. A residue of sediment found in the Core-Catcher P w ^ z 5 t ~ ' ' l ~ ^ H - ^ S2 - ' £ was used for biostratigraphy. I S l S s I l § δ S S Sg | _ I I_ΛJJ — ~ "» ^ ^ CARBON CARBONATE: 6, CC >. FP B CC ~ ~ Λ I ^ I I ~*~1 l i % Carbonate 51 I I _ l H J' 1 L l | No core recovered. (Biostratigraphy based upon sediment streaked onO g % Organic carbon 0.3 S _ C the core liner.)£ I ft

2"S CARBON CARBONATE: 8, CC_ I S_ % Carbonate 6

• ~ | ü E % Organic carbon 0.4^ Note: Graphic lithology represents average composition derived from c |^ smear slides and does not reflect the detailed alternation of sediment « 'S types. Gradational changes between smear slides are arbitrary and do µ |

logic changes. | ^ ^

SITE 503 HOLE A ÇQRE (HPC) 9 CORED INTERVAL 32.6-37.0 r


6G3/1

~5G 4/1

Cycles of CALCAREOUS BEARING SILICEOUS OOZE ranging incolor from greenish black (5GY 2/1) to grayish green (5G 5/2). Grada-

highly mottled. A zoophycus is at 103-105 cm in Section 1. A car-bonate nodule (light gray [2.5Y 7/2]), which is formed around aburrow is at 70 cm in Section 2.

SMEAR SLIDE SUMMARY

Volcanic glass (dk>

1-4 1-90 2-14 2-75M D M D

10/C 2/R- - - I/T10/C 35/A 33/A 62/A

3/R 2/R 5/C82/Da 15/C 15/C 15/C3/R 2/R -

5/C 5/C -5/C 10/C 10/C

5/C 20/C5GY 6/2Si5GY4/1

5GY 3/1

5GY2/1

5GY 4/1

RadiolaSpongeSilicons

a Mien

spiculesigellates

ox-allineCaCO3

CARBONATE BOMB:1-49 err1-79 err1-109 c1-139C2-19 err2-49 err

i = 36%i = 24%m = 28%m - 25%i - 24%i = 22%

CLAY MINERALOGY

5/C-

2-79 c21393-19 c3 49 c3-79 c

(<2µm):

25/A 15/C 55/C 5

m = 5%cm - 22%m = 26%m - 33%m = 25%

2-73 cm


SITE 503 HOLE A CORE (HPC) CORED INTERVAL 37.0-41.4 m

! °

V.*1

I:


EC 0 !&BC, 4/1

Cyclic alternation of SILICEOUS-BEARING MARL, whichgreen (5G 6/2) in color, and SILICEOUS MARL, which is di

70 and 103 cm in Section 2 are highly burrowed. Beds of pyrimeπt, grayish black (N2) in color, are at 114 117 cm in Sect

burrow is at 85 90 cm in Section 1.

grayish

5G6/ 2

N2

6G4/ 1,5G6/ 1,with N2streaks

N2

5G6/ 2

5G4/ 1

5G 6/2

SMEAR SLIDE SUMMARY

Clay mineralsVolcanic glass (It)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellate!

CARBONATE BOMB:1 19 c m 55%1 49 cm =• 46%1 79 cm = 43%1 109 cm = 26%1 139 c m 23%2 19 c m 47%

1 20D35/A_25/A5/C15/C5/C10/C •5/C

2 49 cπ2 79 en2 109 c2 139 c3 19 en3 49 en

CARBON CARBONATE: 10, CC% Carbonate% Orαanic carbon

350.5

2 90 1 50D M37/A 8/C 2/R20/C 98/ [

_10/C 10/C 10/C 5/C

^ = 35%T = 20%m 55%:m = 48%T = 42%i = 50%

SITE

1 z

TIM

E U

c

I—S

503

4TIG

R/

?ONE

1 BIO

STR,

π:z

8 |S gS •°<i Q

S

2

1

T.c

HOLE AFOSSIL

CHARACTER

Ii

CM

o

zzz

CM

S

FM

1

FP

FM

FP

RP

CM

CORE (HPC) 1 1

i

f i

" •

s

£

1

%1

CTI

ON

(Λ

1

2

3

CC

i

ε

•

0.5 — _

i . o

_

_

_

__

CORED INTERVAL 41.4 45.8 m

GRAPHICLITHOLOGY

T~ ~ 1 I —VOID

ZZ Zt

zzzz ZZZHr_ _"jZZZ :

z z z

rZ ZZ

z~z~z~

_ _!"_ _ZZZrrZ~ZZ

?ZZZ ~ _ • " _ • " _

ZZZZ ~ ~SZSISZ.

ZZZZZZ i

ZZZZ zzzzz Z ZZ

ZZZ

z=z=z :

zz= zz

z=z~z :z z z z

ijljlJN' i' i' l'i i i i i i il

G=

_/ ~~*"v >

y~\ _. _rJ \ _• v— —v*

z = £

. _r

_ _r —v

_ —

_ _r

_r\__^_

XT

• 1 i_

L |

LL.

_ L_L

L _ L

1 ~_L.— |

JL_l _

L.l__L

_L!

! >

1 ^1 _

1 _

_L1 _

_L1_

[>

o,,i

DRIL

LIN<

DIST

URB

0

oo0

oo

i

— —

1

•

*


Cycles of SILICEOUS MARL, ranging in co or from light greenish gray(5G 8/1) to dark greenish gray (5G 4/1) in color. Gradations between

greenish black (5G 2/ 1). Pyritized burrows are common. The interval5G 7/1 from 113 132 cm in Section 2 shows faint light colored (1 mm)

layers spaced about 1 cm apart. Mott ling and burrowing are commonthroughout the core.

= 5G 2/1SMEAR SLIDE SUMMARY

2 2 2 140 3 645G 7/1 D D Mto Pyrite ~ 2/R5G 6/1 Clay minerals 39/ A 34/ A 23/C

Volcanic glass (It) 1/T Volcanic glass (dk) 1/T

_ Carbonate unspec. 20/C 15/C 15/C5G4/ 1 Foraminifers 5/C 15/C

Calcareous nannofossils 10/C 15/C 15/C~ Diatoms 15/C 15/C 10/C

5G6/ 1 Radiolarians 15/C 10/C 10/Ct 0 Sponge spicules 5/C 5/C5G4/ 1 Silicoflagellates 5/Cat base

CARBONATE BOMB:1 19 cm = 46% 2 79 cm = 35%1 49 cm = 35% 2 109 cm =43%1 79 cm = 38% 2 139 c m ' 6 3 %

5G6/ 1 1 109 cm = 41% 3 19 cm = 60%1 139 cm = 31% 3 49 cm = 42%2 19 cm = 31% 3 79 cm = 66%2 49cm = 30% 3• 109cm = 69%

5G 4/1 and_ 5 G 2 / 1 CARBON CARBONATE: 11.CC

% Carbonate 31% Organic carbon 0.3

5G 8/1

5G6/ 1,5G 4/ 1 , and

_ 5G 2/1

5G 8/ 1, 6/1

5B 7/1

5G 8/1

5G6/ 1

SITE

iME

RO

CU

NIT

ocsCU

ate

—

5 0 3

z

TRAT

IGR

/ZO

NE

BIO

S

——|

J

—

_

1a

_

T35

S

_

i

1

HOLEFOSS

CHARAC

IzΣ

g

CM

sz

FM

FM

CM

CM

CM

<

FM

A CORE (HPC)LTER

I5

CG

if

DE

"

5~

o

48.7

!.59

49.7

2 4S

SEC

TIO

N

1

2

3

CC

MET

ERS

0.5 —

1 . 0

_

12 CORED INTERVAL 45.8 50.2 m

GRAPH CLITHOLOGY

z"z=: n

‰ r

" _1 _ •• JL•• i .

VOID— • —

Z l n

zzz T T

ZZZZT Z

z~~

rZZ~~^ : :

Z~Z

„ _;

_ _ :

r ZZ

~zz~

Z~Zi zz.: z i

_öz

—zz-zz=z

-zz?zz

r\_ _

vj- -

=c=

- =

_ _<—w-= r^

J- —

=Q=

<>^

= z^2

o=<f

_!_'iI '

_ 1 _

I •

—L_l_

1 •

~ ^

- L -1

I

* | '

Ll_'i

• t

_1_i '

: -L.r _L_"

- J - '

It

A S i-ε y

—

i—

© * *

—

SAM

P

*

*


Cyclic alternations of CALCAREOUS" SILICEOUS OOZE, which isgreenish gray (5G 6/1) and dark greenish gray (5G 4/1) in color, andCALCAREOUS BEARING SILICEOUS OOZE, which is greenish black

5G 4/1 (5G 2/1) to dark greenish gray in color. Gradations between endtypesto in color and composition are common. Burrows and color mott ling are5G 2/1 common. A thin gray (N7) bed at 95 96 cm shows plastic deforma

t ion. The greenish black (5G 2/1) sediment commonly shows enrich ment in pyrite. Carbonate nodules, light gray (2.5Y 7/2) in color andformed around burrows, are at 35 42 and 141 144 cm in Section 1and 122—125 cm in Section 2.

5G 6/1 SMEAR SLIDE SUMMARYand 5G 4/1 1 110 3 10

D DOther heavy minerals 1/TClay minerals 27/ A 35/ AVolcanic glass (dk) 5/C 5/C

~ Carbonate unspec. 15/C 15/C5G4/ 1 Foraminifers 2/R

Calcareous nannofossils 10/C 5/CDiatoms 15/C 16/C

Radiolarians 15/C 15/C5G6/ 1 Sponge spicules 5/C 5/Cand Silicoflagellates 5/C 5/C5G8/ 1

CARBONATE BOMB:~ 1 49 c m 1 2 % 2 79cm = 30%

5G2/ 1 1 79 cm = 24% 2 109 cm =15%and 1 109 cm =19% 2 139 c m 2 0 %5G4/ 1 1 139 c m 1 6 % 3 19 cm = 6%

2 l 9 c m = 1 1 % 3 49c m 38%— 2 49 cm = 22% 3 79 cm = 27%

5G6/ 1CLAY MINERALOGY ( < 2 m l : 2 73 cm

5G 4/1 to Kaolinite 5%5G8/ 1

_ CARBON CARBONATE: 12, CC5G 6/1 % c• ""b°"«e 50and N7 % Organic carbon 0.3

5G 4/1

5G6/ 1

SITE

- R

OCK

INIT

TIM

E

QJ

So

Q_

503yX<

BIO

STR,

!*

1S

1

|o

itium

(R)

. pris

imP

(D)

1

8Q

HOLE AFOSSIL

CHARACTER

1j

CP

0

z

CM

CM

CM

CM

AM

z

j

FM

J

CG

2M

FM

CG

CORE (HPC)

z

s.s

§

53.1

FM

i

I 54

.43

CTI

ON

1

2

3

CC

ETER

S

_

0.5 —

--

1 . 0 -

_

-—

13 CORED

GRAPHICLITHOLOGY

VOID

-_nr_-"-""----r_-_

~~-Z~—-

^~-Z~—

-I-I-I_r_-ir

!.-_-_-_-_r:

-_-_-£?!-_-_-

-Ir-~XIZZ÷~~-

•üHH

-_-_-;

BE1:::i=z:

:-z-i-

: =Q:0= =

'v•_rv

O :

_!_'

_ l _ •- | '

, -' i• i '

"J_"U_'

I '

^ % -o =p-•^ V i •

*^- =-Ti.

" V

O1 :

^<>^<)

—vy-

— v _ ^

—t^^-

i *

i

i~ i

" 1- ._L

•-J-

o0?

INTERVAL 50.2-54.6 m

si

* ® *

1

*

•

5GY 4/1

5GY 6/1

5G 4/2

5G2/1

=SY 7/4

5GY6/1and

, 5G 6/1

5G6/1

5G8/1

—

5G5/1

5G8/1


Cycles of CALCAREOUS SILICEOUS OOZE,ish gray (5G 4/1) to lighbetween the endtypes ofare common with many

greencolorspyriti

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (It)Volcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellates

CARBONATE BOMB:1-109 cm « 46%1-139 cm « 19%2-19 c m - 21%2-49 cm = 30%2-79 cm - 39%2-109 c m - 2 8 %

CARBON-CARBONATE% Carbonate% Organic carbon

1-98D2/R34/A1/T—12/C1/T15/C10/C15/C5/C5/C

2-1393-19 c3-49 c3-79 c3-109

sh grayare Corred bur

1-142M5/C34/A

—10/C-10/C15/C15/C5/C5/C

cm = 2m-41m = 38m - 5 0cm -47

13, CC37

0.2

(5G tmon.ows.

2-10D2/R30/A-3/R10/C5/C15/C10/C15/C5/C5/C

%H>o

>i%

ranging from dark green-/ l ) in color. GradationsBurrowing and mottlingDark spots, zones, and

3-100D1/T35/A-—15/C2/R10/C15/C15/C2/R5/C

SITE

- R

OC

INIT

TIM

E L

_s1-§

ylin

dr

sj1

^ —.2 —K g

'lie

%

503

T

BIO

STR

,

I• |

c2Ci

s:

|

i

HOLE A CORE (HPC) 14 CORED INTERVAL 54.6-59.0 mFOSSIL

CHARACTER

i

CM

FP

o

z

CM

11

CM

CG

| |

g .

°55.

o

6 57

J57

.8

O

1

2

3

CC

ETER

S

_

_

0.5 —-

_

1.0

-

-

-

_

-

-

-

-

-

-

-

GRAPHICLITHOLOGY

-_-_n--

=÷::

I-£h_-_

~^~-~-^-£}£~v ; .

111: ii

ii

ii

i

-'~1- :

— ^ r - •

r =0=O= :r• -<J

i r\

Si/— —^)= :- r^)~^1- :^ _J Λ

^– —v_/

—' :—w—

—'– ;1Λ?^

*= =0

=o

_ L1

— l

_1a_Lj .

1

u. i

L

_ i_l 1' 1

_ iJ ._ l_1—I 1_1

.

—1—l

"li_1_L

_£J.J.J.11

uo l2 CD

3 α

oooooo

oo

SE

α

=©«

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—

I

*

g Cycles of CALCAREOUS SILICEOUS OOZE, which is light greenishE gray (5G 8/1) in color, and CALCAREOUSBEARING SILICEOUSE OOZE, which is greenish gray (5G 5/1) in color. Gradations betweenβ 5GY 5/1 endtypes in color and composition are common. The first section is° highly disturbed. Burrowing and mottling are common as are zonesj° and burrows enriched in pyrite. A carbonate nodule is at 70 cm in^ Section 1, which is probably downhole contamination. A zoophycus is% at 30 cm in Section 3.

5G4/ 1,5 G 2 / 1 SMEAR SLIDE SUM M ARY

— 2 100 3 40D D

5 G 8 / 1 • Pyrite 1/TN7, and Clav minerals 35/ A 33/ AN 6 Volcanic glass (dk) 1/T

Carbonate unspec. 10/C 5/CForaminifers 2/R

6 G 7 / 1 Calcareous nannofossils 15/C 5/C— N 4 Diatoms 15/C 20/C

Radiolarians 15/C 20/C' Sponge spicules 2/R 10/C

_ N 4 Fish debris 1/T Silicoflagellates 5/C 5/C

5GY 6/ 1,N 6 CARBONATE BOMB:

_ 2 19 c m 4 3 % 2 139 cm = 25%2 49 cm = 33% 3 19 cm 23%

5G B/1 2 ? 9 c m _ 3 6 % 3 4 9 c m = 2 0 %

5 G β " 2 109 cm = 48% 3 79 cm = 1 7 %

5 G 4 / 1 • CARBON CARBONATE: 14, CCN6 % C a r h o n a t e 36

_ % Organic carbon 0.2

5G7/ 1

5G5/ 1

—

5GY5/ 1

5Y4/ 2

Note: Graphic lithoiogy represents average composition derived fro

SITE

1 Z

1JS

cs;9

0_

irh

co

£

503o

a:

iTR

ATIG

ZON

IB

IO!

it

—

E

ö

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11

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I

S. pe

n

HOLE

FOSS

A CORE (HPC)L

CHARACTERin

i|

CP

FP

w

NOFO

SSII

Zz

FP

1

CM

1

_

1

1I

ACG

CG

CG

3OTT

OMSU

B-I

1.00

o

8

§3

62.7

7

zo

1

2

3

CC

«

0.5 —

-

_

1 . 0 -

-

-_

-

-

_

-

15 CORED INTERVAL 59:0-63.4 m

GRAPHICL THOLOGY

-jn

" _

Z~I"-~-j

7--1-7-

-_—_r

µ---~:_-_-rj>I

£"~:" –

frl-

-_-^

-----

-~-~

L--I-

;->!

j-i_ __ o _— v ^ -

J - -—^y-

" \ - =

rv_ _

—v>—5 = =

_/~\_

c= =n_ _

3= =

J - =

-\_ _

—v -) = =

)= =

=0=

- J . "~_J_"~ f '

" X "~ 1 '

- X .

~ i •~_L'

—L.~ l "

_ _

~Λ:

I ~

. —LI 1

1 * I '

~ J •. JL.'

I

| '

l_ .

_L•~ _L' L '

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i

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l |£5O

oo1

1

11Is

f i

_

*• "

s

SAM

I

*

*

*

5GY4/ 1,5G 4/ 1,N4

N7toN5

5G7/ 1

5GY 6/1

_5G 6/ 1,

5Y 4/2

5GY 6/1

= 5G 3/1

5G 6/1


Cycles of CALCAREOUS SILICEOUS OOZE(5GY 6/1) in color, an(5G 4/2) in color. Gradation are common. Mottburrows showing enrichnblack (5G 3/1) in color[ 2.5Y7/ 21I formed arouat 100 120 cm inSectio

d SILICEOUS MARLtions betweening and burrc

lent in pyrite.are common.

nd burrows aren 1 and 50 cm

SMEAR SLIDE SUM M ARY

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.

Calcareous nannofossilsDiatomsRadiolariansSponge spiculesFish debrisSilicoflagellates

CARBONATE BOMB:2 79 cm = 44%2 109 cm = 41%2 139 c m 13%

CLAY M INERALOGY l<Smectite 97%Chlorite &

Kaolinite 3%

CARBON CARBONATE% Carbonate% Organic carbon

2 62 2 90M D

I/ T30/ A

100/D 15/C 3/R

15/C10/C15/C5/CI/T5/C

3 19 cm = 513 49 cm = 32

2 m) : 2 71 c

15, CC28

0.3

endtypwing a

which is greenish graywhich is grayish olive

s in coior and composi e common. Zones and

grayish black (N2) and greenishCarborfoundn Secti

2 140DI/ T25/ A2/R15/C2/R20/C15/C15/C5/C

X.X,

ate nodules (light grayπ the disturbed sections> n2.

3 20M5/C23/ C2/R15/C

20/C15/C15/C5/C

SITE 503 HOLE A CORE (HPC) 16 CORED INTERVAL 63 . 4 67 . 8 m


Cycles of SILICEOUS NANNO MARL, ranging from dark gre(5GY 4/1) to greenish gray (5G 6/ 1, 5GY 6/1) in color.

in color. The sediment is burrowed and mottled in the less. Zones of richm

CarbonatiCalcareouDiatomsRadiolarii

; unspeis nann<

Sponge spicules

CARBONATE B2 79 cm =2 109 cm2 139 cm3 19 cm =

= 38%= 51%= 53%

44%

CARBON CARE% Carbon% Organi<

at e

; carboi

Jfossils

OMB:

IONATE:

20/C20/C15/C10/C5/C

16, CC43

0.5

Graphic lithology represents average comp•slides and does not reflect the detailed alti

SITE 503 HOLE A CORE (HPC) 1 7 CORED INTERVAL 67.8 72.2 m


SILICEOUS MARL, fairly unifo

5Y 4/ 3,5G7/ 1 ,N5

SMEAR SLIDE SUMMARY

Clav mineralsCarbonate unspecForaminifersCalcareous nannofossilDiatoms

.RadiolariansSponge spicules

2 10D15/C25/ Aδ. c

s 25/ A15/C10/C5/C

CARBON CARBONATE: 17, CC% Carbonate

SITE 503 HOLE A CORE (HPC) 19 CORED INTERVAL 76.6 81 .0 m

SITE

IME

RO

CU

NIT

c

—

503o

*PH

STR

ATIG

R/

ZON

EBI

O:

I I| l1 :* α

j§

a.t o

HOLE

zi

FOR

FP

AFOSSIL

CHARACTER

1CM

z

i5

CG

CORE (HPC) 1 8 CORED I N T E R VAL 7 2 . 2 7 6 . 6 m

§ Si

:,o|

72.2

6 7;

SEC

TIO

N

CC

MET

ERS

GRAPHICLITHOLOGY

VOID

z

i 3

1

31


5Y5/ 2, SILICEOUS NANNO MARL greenish gray (5G 5/1) in color.5G 5/ 1

SMEAR SLIDE SUM M ARYCC, 10D

Pyrite 1/TClay minerals 17/CVolcanic glass (dk) 2/RCarbonate unspec. 25/ ACalcareous nannofossils 25/ ADiatoms 15/CRadiolarians 10/CSponge spicules 5/C

CARBON CARBONATE: 18, CC% Carbonate 33% Organic carbon 0.4


VOID

5G 6/1

Note: Graphic lithology re|

types. Gradational changesnot imply actual lithologic

• eflect the detailed I

Cycles of SILICEOUS BEARING NANNO MARL ranging in color froilight greenish gray (5G 8/1) to dark greenish gray (5G 4/ 1). Are<enriched in pyrite, dark gray (N3) and greenish black (5G 2/1) in colo

5G8/1N5.N4,5G4/1

N7.N6,N5,5G4/1

Clay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spicules

CARBONATE BOMB:1 79 cm = 42%1 109 cm = 37%1 139 cm = 35%

17/C_2 5 / Λ3/R35/ A10/CBIC5 'C

2 79 c2 109? 133

?• j/ c3/R15/C

35/A15/C5/C5/C

• n 3!cm = :cm = '

CLAY MINERALOGY (< 2 m ) : 2 71 (

CARBON CARBONATE: 19, CC 19, CC% Carbonate 31 32% Organic carbon 0.3 0.1

SITE

RO

CIN

ITTI

ME

g§

_> (α

503oi

ATIG

RJ

ZON

E

CC

5

_E

s1f i

1— 1§ 8.

1 0 1!ci

o

1

ylin

dric

aAb

ove

N. c

HOLEFOSS

CHARAC

1s

S

FP

FP

Izzz

FP

<

CM

CM

CM

A CORE (HPC)LT E R

!

I

CG

TOM

1

n)

5?ss5

00

Q ©

s>

sfi

1 85

.35

E

CTI

ON

SS

1

2

3

CC

ETER

S

S

0.5 —

_

1.0 —__

_

_


GRAPHICLITHOLOGY

> ,

i

i A.

VOID

ill

jr.

—

l|i

> _ :

II

2_ n j'1'

—

> :

" TLr_ I I

~ _ •

:J%K

iH _r .

r~ ~\

VOI

=0=v_ _/•_r\_2 " / yj

^ ^ ^

• ^ ^

< ^ v—x^r~

=or —v

n _ _

s• w

_ L

* ^ iJ .JL."1

1

_ L

."| ~J.

± J"T L

, J

J .

" " " J . J .

»J L

. _L^ _ L

L

Uz

Hiio

oo

i iSS

1

• »

1<

•


Cyclic alternations of SIL CEOUS MARL, which is greenish black (5G2/1) and very dark greenish gray (5G 3/1) in color, and SILICEOUS

5G 4/1 NANNO OOZE, which is light yellowish gray in color. Gradationsbetween endtypes in color and composition are common. Sedimentsare mostly uniform, i.e. few burrows or mottles. A zone of pyrite

— enirchment is at 70 72 cm in Section 2. A carbonate nodule is at 2 cmr ^ y . , . in Section 1 — probably downhole contamination.

5f i 2/1 SMEAR SLIDE SUMMARY

Pyrite 3Clay minerals t

_ Volcanic glass (dk) ICarbonate unspec.Foraminifers

5G 4/ 1 Calcareous nannofossils ;DiatomsRadiolariansSponge spicules £Silicoflagellate: i

110 3 50) Din 5/A 5/C/R 5/C 20/C/T 0/C 45/A5/C 10/C0/C 5/C/C 10/C/C 5/C

CARBONATE BOMB:1 19 cm =14% 2 109 cm = 1%1 49 cm =18% 2 139 cm = 53%1 109 cm = 5% 3 19 cm = 69%

5G 2/1 1 139 cm = 3% 3 49 cm = 65%2 19 cm = 13% 3 79 cm = 65%

5G3/ 1, 2 49 cm = 8% 3 109 cm = 66%5G2/ 1 2 79 cm = 26% 3 139 cm = 26%

CLAY MINERALOGY (<2 m) : 2 71 cmSmectite 85%

~ Illitβ 9%Chlorite &

Kaolinite 6%6 Y 8 / 1 CARBON CARBONATE: 20. CC


5GY 5/1

SITE 503 HOLE A CORE (HPC) 21 CORED INTERVAL 85.4 89.8 m

Li

α>

öciAµ

S

uX

ATI

GR

AI

ZON

EBI

O!

o:

JS

.to

1§

it J"§ et!"§5!

1Q

5

11"11<

FOSS LCHAR AC

1I

FOR

FP

FP

i°I

CM

z

o

1

F M

C M

T E R

15

FIV

TOM

I

it§'&

oσ i

i8

g

1

2

3

CC

ETER

S

0.5 —

1.0 —

—

—

_

GRAPHICLITHOLOGY

I :

—.~

—• * .

_

W—

B——I

z:

j

y"V

_iP

_r

_n

_r

T

n

:

V: =

O

o .

""~JL~J 1 i * . * i *—

, *— , J L ~L

i

* i * JU J

_t _~ • l _•"_!_ JL.'Lu_" ^_l_ i" » , •" J _ _ i

L J

" j ^~J •

i " ^ i " ^

— L _ i L L j _ J ;

J _ i —" i JL! _1_ L _L , J— |

!_ J_

i i^ D

= 5

o

!i

URES

55V> V)

»O<

»Φ «

oβ •

»«<

* * *

z1

PLE

SAM

*

_ 5G 4/1

5G 6/1

5G6/ 1

~~ 5G 8/1

5G 6/1

5G7/ 1

5G8/ 1_

5G6/ 1

5G7/ 1

N2.5B7/ 15B5/ 1.5G

5Y8/ 2

5G6/ 1

5G5/ 1

5G6/ 1.BG7/ 1

5G5/1


SILICEOUS BEARINGranging from light gree

NANNO OOZEnish gray

4/ 1). Burrowing of color bounda

disturbed part of Section 1.

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellate:;

CARBONATE BOMB:1 19 cm = 52%1 49 cm = 52%1 79 cm 39%1 109 cm = 49%1 139 cm = 53%

2 60D 15/CI/ T25/ A2/R40/A2/R10/C5/C

2 19 er2 49 en2 79 en2 1092 139

CARBON CARBONATE: 21, CC% Carbonate% Organic carbon

8/1

500.1

(5G 8iesis

3 10D3/R17/C 20/C1/T40/A5 / C

10/C2/R2/R

n 39

showing/ I) to dommon

3 95D 18/C 20/C3/C35/A10/C10/C2/R

n = 53%n = 47%m 4 3%m = 72%

cyclic color variationsark greenish gray (5G

Many spots of pyrite

3 19 cm = 51%3 49 cm = 50%3 79 cm = 28%3 109 cm 46%


Note: Graphic lithoiogy represents average composition derived fromsmear slides and does not reflect the detailed alternation, of sedimenttypes. Gradational changes between smear slides are arbitrary and do

logic changes.


. (Biostratigraphy based upon sedir


SITE

/IE -

RO

CU

NIT

c

sj?Q.>

503

311

I

RAT

IGR

yZO

NE

[BIO

ST

S|

a _o •J< £

"1gúT 1— a.

1 çI i

1ci

§

1

z

g

FP

HOLE A CORE (HPC)

FOSSILCHARACTER

!z

z

CM

ILAH

IAN

s]

SIt -

CM

3TTO

M

1

ii

-I

S>

i"

CO

j 96.

86 9

SECT

ION

1

2

CC

MET

ERS

0.5 —

1.0 -_

-

-

-

23 CORED INTERVAL 94.2-98.6 m

GRAPHICLITHOLOGY

~-

~-~T-T"_

-77-:7r_-_ -_ :- "777-2_--~-"

—

~—-_;-777

77

_

=

=

=

=

=

=

=

" - l _ _L~ I ~*~ ,~ i j- , — 1 — ,

J- J.U. _l_

i i_ _i_

- 1 -1—

_l_ _L

_-*-!?-_1_ _L"-1_•J~X

1—_J_ " *_1_ _!_'

1 > *"TJ. .""~-L.-1-.

M±÷i•

j _ ._i_ _i_

ú\lj

K £2 -

E ° I—


~ V O I D Cycles of SILICEOUS-BEARING NANNO MARL ranging from oliyegray (5Y 5/1) to light greenish gray (5G 7/1) in color. The core ishighly disturbed with carbonate nodules at 100 cm in Section 1 and76 cm in Section 2

5G6/1SMEAR SLIDE SUMMARY

2-107D

Pyrite 2/R . , . ;Clay minerals 15/CCarbonate unspec. 10/CForaminifers 3/R : : .Calcareous nannofossils 45/ADiatoms 15/CRadiolarians 5/C ;Sponge spicules 3/R " '

.— VOID Silicoflagellates 2/R i -


a s w i . . . . - : ; .5G7/1,5Y5/1

5G 6/1~ N4,5Y5/1 • ,.

5Y5/1

smear slides and does not reflect the deitypes. Gradational changes between smenot imply actual lithologic trends. Color

-logic changes.

SITE

u

TIM

E

c

s

iarl

503oi<

ATI

Gl

ZONE

BIO

STft

11

1al>

<

1Iε

•g çε •§5 5« E

ε J1

HOLE

FOSS

A CORE (HPC)L

CHARACTER

a.

l

CM

1|

CM

z

j•

RM

FM

CM

FM

TOM

2%3 '8

__*~.o

so

.48

o

1 10

2.70

IOIX

3

t o

1

2

3

CC

ETER

:

5

0.5 —

i . o

_

24 CORED

GRAPHICLITHOLOGY

Mili

_^~ •

_ _

777

~—~JT.

I ~—Zr. 77~—ill

—

Φ

jr.—

I 7 7~ r7

77777

>:

I|I

r7III

7 7

!i!

\ _ _

/ ^^ ^> __ n _

~y~<~ =

^j ^ z Λ ^_ _/2 r^r— ——/ "L.

< >

y = J v

^C —\

\ J

—w

~ i , .

_ .1—L_~L"_L, 1—

I

i _ _1_ , L_ 1

1— 1~JL_~ l~ i ~ 1" | • ^~

~ L.i

• 1 _ 1 _ '

J — X.

i —*

i J.

1_ J J 1 1— i

.L ~1"• 1 , ^

u

oor\

1

0o

INTERVAL 98 .6 103.0 m

if

I L

zz

s

*

5GY6/ 1,5G7/ 1,N6

5G7/ 1

5Y5/ 1,_ 5Y8/ 3

5G7/1

~ 5G6/ 3,5G7/ 1,

_ 10YR 7/2

5GY4/ 1,5Y4/3

5G8/1

5Y 4/2,, 5Y 5/3

5G7/1

_

5Y 6/2,5G 6/3,5GY4/ 1,

5Y 4/3,N6, N4, N5


Cycles of SILICEOUS NANNO MARL, rangigreenish gray (5G 8/1)gray (5GY 4/ 1) and olivexcept for the laminated

ig in color from tightand pale yellow (5Y 8/3) to dark greenish

(5Y 4/ 3). Mottles an i burrows are commonnterval from 127 135 cm in Section 2. Areas

disturbed section at the tOD of the core.


PyriteClay mineralsVolcanic glass (dk)GlauconiteCarbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellates

CARBONATE BOMB:1 109 cm = 44%1 139 cm = 42%2 19 cm = 47%2 49 c m 14%2 79 cm » 63%

CLAY M INERALOGY l<Smectite 89%Illite 5%Chlorite &

Kaolinite 6%


2 35 2 40 2 110M D D6/C 7/C 18/C 13/C2/R 10/C 10/C 10/C 10/C5/C 5/C40/ A 40/ A 45/ A10/C 15/C 10/C5/C 10/C 10/C5/C 5/C 5/C

2/R 2/R

2 109 cm = 70%2^139 cm = 3 1 %3 19 cm = 5 3 %3 49 cm = 52%3 79 cm 45%

2 m): 2 133cm

24, CC61

0.3

2 128M3/R8/C1/T_10/ C • • i, .15/C30/A10/C10/C5/C3/R

SITE 503 HOLE A CORE (HPC) 25 CORED INTERVAL 103.0 107.4 r

g]giet


'ered. (Biostratigraphy based upon sCore Catcher.)


SITE 503 HOLE A CORE (HPC) 26 CORED INTERVAL 107.4-111.8 m


No core recovered. {Biostratigraphy based upon sedimenton Core-Catcher.)

SITE

L1 Z

TIM

E

g

1CL

1

503yX<

1 BIO

STR

/

a

1|— z| |2 §

_

2

HOLE

FOSSCHARAC

s

1

FP

«

OS

SII

z

z

AM

|

A CORE (HPCILTER

1

CM

s

Is

CO

iü•

z0112

1

CC

2

0.5 —

--

1.0 —

_

2 7 CORED INTERVAL 111.8-116.2 m

GRAPHICLITHOLOGY

Z-:Z--I

-:0= -

t

' 1 1

J_ L α_—'— l

a_^J !VOID

J O = i_i_——* •'r i ^r i_ . .

J||oooooooi

!

SA

MP

LES


I SILICEOUS NANNO MARL, highly disturbed, light gray (N7 and N8)o to medium dark gray (N4). A carbonate nodule is at 15 cm.

SMEAR SLIDE SUMMARY1 113

H l m • Claym.nerals L eN 5 N 6 • Carbonate unspec. 10/Cm• Foraminifers 2/R5Y 7/ 3 Calcareous nannofossils 45/ A

Diatoms 15/CRadiolarians 10/CSponge spicules 5/CSilicoflagellates 2/R




SITE

x

I Zill =3

cocü- •

503y

s et N

BIO

ST

—

CO

_

z

t

1

HOLEFOSS

A CORE (HPC) 29 CORED INTERVAL 120.6-125.0 mL

CHARACTER

I|

_|s1

• S

<

FM

IZz

CM

z

|

CM

CM

CM

E

CM

CM

CG

CG

CG

CM

- —

las '6£i

rvi -

-

-

in

I 12

4.77

1

Z

LU

1

2

CC

:TER

S

s

--

0.5 —----

1.0 —

-

-

-

-

-

__

-

-

GRAPHICLITHOLOGY

c>< ~ v -

"v--r\

÷n>

r^y=£>

3= :

^y~ j - ~•

=0y= ••

=Q

JD•^y.

=Q" > - ;

_ f ^

^~\J

J-

*t_ .j -

J - - l _1— • "i_-J-_L_-J_ _ l _ "i_. _ l _ "

- i _ _L_~

, ~^~ ! ', -i- -

1

-1—_!_-"—

J _L_

, —'— , —-1 - .1 " ^

-L-^-L-•J— - 1 _ "

i•^-L.-_i_ _i_"

i _

J_ _L_J_ _L_"J _ ^ - l _ "j i "

-1— _

J_ _ l_

u

' rr

if1

u ?i IT

- * •

' '

l*f"//'

$

5 ^

^ ^

E2i

•

*

5G8/1,N8, N7

5G 4 /1 ,5G2/1 ,

N9

5Y 8/2,5G8/1 ,N7

5G7/1 ,5G8/1

5GY 6/1

5G5/1,5Y 6/3,5Y 6/2,N5, N7

~ 5Y 7/3,5Y 6/2,5G7/1

-5G4/1 ,5G2/1,SY 6/3,N7

_N7.5Y8/3

= N6, N55G 6/1, 5 /1.

5GY5/15G4/1 .5G2/5Y 6/3, N7,5Y8/1

_5Y 7/3,5G7/1,N7

5G7/1

N4, N5, N7


Cyclic alternationNANNO OOZE raand yellowish gray

are common. Burroburrow is at 29 cmtends from 116 cmgreen (5BG 5/2) eSection 3.

of SILICEOUS NANNO MARL TO SILICEOUSnging in colo(5Y 8/2) to g

wing and colein Section 3.

from light greenish gray (5G 8/1)eenish black (5G 2/1) and dark green-

r mottling are common. A zoophycusA HPC "collapse" coring artifact ex•

in Section 1 to 5 cm in Section 2. A grayish bluenrichment in

SMEAR SLIDE SUMMARY

Clav mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofoDiatoms

Sponge spiculesSilicoflagellates

1-45D13/C-10/C2/R

ssils 45/A12/C12/C3/R3/R

CARBONATE BOMB:1-19 cm »64%1-49 c m ' 17%1-79 cm " 5 2 %1-109 cm = 35%1-139 cm = 44%2-19 cm 35%2-49 cm 39%

SmectiteChlorite &

2-79 c2-1092-1393-19 c3-49 c3 79 c

97%

3%

montmorillonite is at 87-90 cm in

2-70 3-88D M10/C 23/C1/T -15/C 15/C2/R -46/A 40/A13/C 10/C10/C 10/C2/R 3/R2/R -

-n -63%cm - 35%cm = 60%•ti - 37%

m 44%m = 63%

Note: Graphic I ith ol og y represents average composition derived from

not imply actual lithologic trends. Color variations approximate lithologic changes.

SITE 503 HOLE A CORE (HPC) CORED|NTE_RVAL 125.0-129.4 r

: - R

OC

JNIT

IME

1-

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2

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GRAPHICLITHOLOGY

VOID \— —

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yr~

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j —

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1 —L

i t

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s

5G 6/1,5G 7/1,5Y 8/2, N4

5G8/1,5Y8/1

_

5G7/1,5GY 6/1

_5G6/1,5Y5/3

N7.N8,5G8/1

N8


Cycles of SILICEOUS NANNO OOZE ranging ingray (5Y 8/1) and lighrowing and mottling arin Section 2. Below thPyrite enriched zones awood is at 66—73 cm in

greenish gray(5G 8/1) tccommon from the top

is boundary the sedimend burrows are commonSection 2.

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossils

RadToTariansSponge spiculesSilicoflagellates

CARBONATE BOMB:1-19 cm = 36%1-49 cm = 48%1-79 cm = 52%1-109 cm -62%1-139 cm-38%

D2/R10/CI/T10/C2/R45/A12/C12/C4/R2/R

2-19 cm = 65%2-49 cm = 65%2-79 cm - 67%2 109 cm = 69%

color from yellowisholive (5Y 5/3). Bur-

of the core to 40 cmt is highly uniform.A possible piece of

SITE 503 HOLE A CORE (HPC) 3JL CORED INTERVAL 129.4-133.8 m

Note: Graphic lithologysmear slides and does n

logic changes.


5G 6/1,5G7/1,5G8/1

Cyclic alternation of SILICEOUS NANNO OOZE AND SILICEOUSNANNO MARL ranging in color from pale olive (5Y 6/3) and greenishgray (5G 6/1) to light greenish gray (5G 8/1) and very light gray (N8).Highly burrowed and mottled throughout. Individual burrows and

10/C 10/C 10/C 10/C2/R 3/R 2/R

5G8/1,5G 6/3,5Y 6/3,N2.N4

5Y 6/3,N2,5G 6/1

N7, 5G 7/1

5G8/1,5Y 8/3.

RadiolariansSponge spiculesSilicoflagellates

a Black nodule

CARBONATE BOMB:1-79 cm = 40%1-109 cm = 30%1-139 cm = 66%2-19 cm = 53%2-49 cm = 63%2-79 cm = 37%2-109 cm = 57%

10/C5/C2/R

2-1393-19 c3-49 c3-79 c3-1093-139

10/R 15/C 25/C 3

cm = 52%m - 42%m = 44%m = 54%cm = 52%cm » 60%

CLAY MINERALOGY (<2µm): 2-71

N7.5G7/1

5G8/1.5Y8/3

5G8/1.5G6/1

SITE 503 HOLE A C O R E ( H p c ) 32 ç 0 R E D INTERVAL 133.8-138.2 m


Cycles of SILICEOUS MANNO MARL raniπg in colo(N7) t o pale olive (5Y 6/ 3). Mott ling is present. A <around a burrow is at 33 cm in the disturbed section.


Clay minerCarbonateForaminifeCalcareousDiatomsRadiolariarSponge spi•Silicoflagel

unspec.

nannofossil

is

'Mies

13/C10/C5/C

s 40/ A10/ C10/ C5/R



Σ

É

r•-Mooo

M&A

i |θoooo



N4, N5, N8

5G6/ 1,N2,5G8/ 1

Note: Graphic lithology represents average composition derived from

types. Gradational changes between smear slides are arbitrary and donot imply actual lithologic trends. Color variations approximate litho logic changes.

SITE

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2

503

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3 4 CORED INTERVAL 142.6 147.0 m

GRAPHICLITHOLOGY

_ I~ T

zr>I

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Cyclic alternation of CALCAREOUS BEARING DIATOM OOZE,Rr v s/ 1 MS d °m i n a n t ' V <=üve <5Y 5/4) in color, and light greenish gray (5GY 8/1)O U T 0 /1 . IMD S | L | C E O U S NA|MNO MARL. Gradations in color and composition be-

tween endtypes is common. Section one is very disturbed throughout.The sediment is highly burrowed and mottled throughout.

SMEAR SLIDE SUMMARY2-110 3-55D D

Pyrite 1/T 1/T— Disturbed Clay minerals 19/C 14/C

Volcanic glass (dk I - 1/T5GY6/1 , Carbonate unspec. 7/C 5/C5GY8/1, Foraminifers - 2/Rl ° i ' , l ' r n Calcareous nannofossils 8/C 40/A5Y4/3 D i a t o m s 5 0 / A 2 0 / C

Radiolarians 7/C 10/CSponge spicules 5/C 5/C

— Silicoflagellates 3/R 2/R5G8 /1 , N7,5Y 8/1, 8/3 CARBONATE BOMB:

_ 2-19 cm = 48% 2-139 cm = 41%5G8/1 7/3 2-49 cm = 66% 3-19 cm = 51%

2-79 cm = 58% 3-49 cm = 41%2-109 c m - 2 %

CLAY MINERALOGY (<2µm): 2-71 cm~ Smectite 99%

5Y5/4, .5Y 7/3, C h l o π I e &

5Y3/ 2, Kaohnite 1%5G8/1

5GY8/1,5Y6/3,5Y5/3

—5G7/1,5Y 7/4,5Y6/3

5G6/1.5Y6/4, Nδ

5G7/1,5Y7/4

SITE 503 HOLE A Ç Q R E (HPC) 35 CORED INTERVAL 147.0-151.4 m

IJ psiU••1o

II


5G7/1,5G6/1,5GY6/1,5Y6/3

Itly greenish gray (5G 6/1 and

PyriteClay mineralsCarbonate unspec.

RadiolarianSponge spicFish debrisSilicoflagell

35/A--:: C



Cycles of SILICEOUS NANNO MARL,greenish gray (5G 8/1} and yellowish gra(5G 6/1 and 5G 5/ 1). Burrows, mottles, ar

I/ T 5/C 19/C 15/C 12/C

10/C 10/C 10/C

Calcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellates

CARBONATE BOMB:1 19 cm = 65%1 79 cm = 63%1 109 cm = 31%1 139 c m 4 9 %1 149 cm = 69%

35/ A20/C8/C5/C2/R

2 19 c2 49 c2 79 c2 1093 19 c

40/ A15/C2/R5/C3/R

m = 65%m = 60%m = 62%cm = 63m = 56%

40/ A20/C8/C2/R5/C

%

CLAY MINERALOGY (< 2 m): 2 71

fleet the detail*

• ends. Color vari

SITE

IME

RO

CU

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8S

503uX

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BIO

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1

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1

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GRAPHICLITHOLOGY

~ j_~x~ i ~*~ iIJ ^> • ^ 1 , —I— t

VOID

:

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z

L

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TI _j

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, * l 1 1_ 1

J_ _1_I II —*— , —L

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Cyclic alternation of SILICEOUS BEARING NANNO OOZE, domin 5Y 8/1 antly yellowish gray (5Y 8/1) and light greenish gray (5G 8/1) in5G8/ i[ color and SILICEOUS NANNO OOZE, dominantly light olive gray5G 7/3, (5Y 6/2) and greenish gray (5G 6/1) in color. Gradations in composi 5Y 8/3, t• n and I betw n th dt B ouu ri t t l5 G 7 / 1 ' are common Many spots zones and burrows show pyrite enrichment

A carbonate nodule is at 50 cm in Section 1.

SMEAR SLIDE SUMMARY1 150 2 25D D

Claymiπerls 13/C 5/CCarbonate unspec. 10/C 10/CForaminifers 5/C 2/RCalcareous nannofossils 55/A 50/ADiatoms 10/C 20/CRadiolarians 5/C 7/CSponge spicules 3/R

~ Silicoflagellates 2/R 3/R5Y 6/2,5G6/ 1, CARBONATE BOMB:

1 49 cm = 66% 2 19 cm = 41%5G 8/1 ' " 7 9 c m = 6 8 % 2 ' 4 9 c m " 6 2 %

5Y8/ 31 1 109 cm = 77% 2 79 cm = 65%5G8/ 3, 1 139 cm = 74% 2 109 cm = 71%5Y 7/4,

j j , 5 8 / 1 • CARBON CARBONATE: 37, CC% Carbonate 71% Organic carbon 0.3

5Y8/ 1,5G 8/1

SITE 503 HOLE A CORE (HPC) 3 8 CORED INTERVAL 160.2 164.61

LEZ


SILICEOUS NANNO MARL.

CARBON CARBONATE: 38. CC

% Organic carbon 0.3

8 SITE 503 HOLE A CORE (HPC) 39 CORED INTERVAL 164.6 169.0 r

A

SITE 503 HOLE A C O RE (HPC) 41 CORED INTERVAL 173.4 177.81


5G8/ 1,N7, N4,5G6/ 1,5Y7/ 3

Cycles of SILICEOUS NANNO MARL,green (5G 8/1) to pale olive (5Y 6/3) inendtypes in color are common. Slightly mS? highly burrowed and mottled below. Z•

10/C 15/C3/R 10/C 7/C2/R 3/R45/A 40/A15/C 15/C7/C 10/C

5GY8/ 1.6/ 1,5Y 7/3, N6

5G7/ 1,5Y7/ 3

Carbonate tForaminifeCalcareousDiatomsRadiolarianSponge spicSilicoflagell

CARBONATE BOMB:

5Y6/ 3

5G7/ 1,5Y 6/3,5G6/ 1

5Y7/ 2,5G6/ 1,5G4/ 1,5Y 4/3, N5

5G7/ 1

5G7/ 1,5G 7/3,N5. N6. N7

1 109 cm = 73%1 139cm 60%

CARBON CARBONATE:% Carbonate% Organic carbon

2 79 cm2 109 c2 139 c

39, CC52

0.3

= 58%m = 43m = 48

SITE

RO

CIN

ITIM

E

S

Jia>k• '

8s

ate

503

X

ftTIG

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JE

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GRAPHICLITHOLOGY

^jTT-1-1VOID

——

r.zl~—-zZ~-

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o~z

- =- =

J - , J-

i i i. _L

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i

j

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STR

I i

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5GY 6/1

Dominantly dark greenish gray (5GY 6/1 and 5G 6/1) SILICEOUSNANNO OOZE. Burrowing and mottling are common. There are

— many zones of pyrite enrichment.5G6/1,5GY6/1,5Y6/3, SMEAR SLIDE SUMMARY5Y7/4, , . 6 ON7.N5 D

Clay minerals 12/CCarbonate uspec. 10/CForaminifers 5/CCalcareous nannofossils 45/ADiatoms 12/CRadiolarians 10/CSponge spicules 3/RSilicoflagellates 3/R

CARBONATE BOMB:1-49 cm = 64%1 -79 cm = 48%1-109 cm = 54%



5G6/1,5G5/1,2.5Y 6/4.

5G7/1,6Y 7/3,5G6/1,

Cycles of SILICEOUS NANNO MARL, ranging in color from greigray (5G 5/1, 5G 6/1) to light greenish gray (5G 8/1). Gradaibetween endtypes in color are common. Highly burrowed and mothroughout. Spots and burrows with pyrite enrichment are comr

SMEAR SLIDE SUMMARY1-35D1/T19/C2/R10/C3/R35/A10/C8/C

2-40D„

14/C1/T10/C1/T45/A10/C10/C

5G5/1,5G 6/1,5Y 5/3,

5G7/1,5Y 7/3,5G6/1,

5G 6/3,5GY6/1,2.5Y 6/3

5G7/1,5Y 7/3,5G6/1,N3,2.5Y 7/2,2.5Y 5/2

CARBONATE BOMB:1-19 cm1-49 cm1-79 cm1-109 er1-139 er

= 31%= 32%- 4 1 %

n = 30%n = 44%

2-19 cm2-49 cm2-79 cm2-109 er2-139 er

= 59%= 52%= 28%

n-59%n = 41%

3-19 cm3-49 cm3-79 cm3-109 er

= 49%= 56%= 52%

11 = 63'

CLAY MINERALOGY (<2µm): 2-71 (Smectite 100%


: Graphic lithology re|

;. Gradational changesmply actual lithologicchanges.

of sediment

SITE 503 HOLE . A CORE (HPC) 4 2 CORED INTERVAL 177.8 182.2 m SITE 503 HOLE A CORE (HPC) 43 CORED INTERVAL 182.2 186.6m.H FOSSIL y FOSSILJ CHARACTER J CHARACTER

g 2 co I co I g I I g g g < „ [ , 1 , 1 I z „T l P i | I §_ g P LJTHOIOGY J < l UTHOLOG.CDESCR.FT.ON f t | § £ | | | _ | £ ™£™y | ?S LITHOLOGIC DESCRIPT.ON

•= 1 I I I III IliiS p I I I 1 III ill! 1o" ^L Zfe 1 .. β • ' r i — ^ ~ = ~ ~ —VO I D§ " J u • • ^ i . 5 G 8 / ] Cyclic alternation of SILICEOUS BEARING NANNO OOZE, which is _ 8 _r\ 1 L. j£ " ~ = * i * " — light greenish gray (6G 8/1, 5GY 8/1) and pale yellow (5Y 8/3) in ™ " E " ^ j _ _1 _

; < > _L I ' color and SILICEOUS NANNO MARL which is dark greenish gray | ' J _ _L cvcles of SILICEOUS BEARING NANNO OOZE, ranging in color_ _ ^~ . * , • ( 5 G 4/ u a r l d 0 | i v e ( 5 Y 4/1) i n color Gradations in color and composi | O J _| _ 1 _L. f r o m dpminantly grayish green (5Y 6/2 and 5G 6/2) and greenish gray

S CM rr rC • 1 1 I • Kr?/ ! ' tion between endtypes are common Highly burrowed and mottled 3 " 7 z : • L . O . 5GY 6/1 (5GY 6/1) to dominantly light greenish gray (5G 8/1 and 5GY 8/1) C G β • B ‰ O " _! _ * , I v l / i ; throughout. Spot and burrow enriched in pyrite are common, and are | C G 0 5 ~ ^ ^ ) J , J and pale yellow (BY 8/3). Gradations between endtypes in color areS ~ • = L _i_• 5G8/ 1, medium gray (N5) and medium dark gray (N4) in color. .0 " • . . l _ J _ common. The sediment is very uniform from the top of the core tog r ^ Q : • ^ J _ " J ~ »* N 6 ε ~ SΛ I " " ~ l ~ 1 1 1 0 C m i n Sβc t i °n 2• b e l o w t h i s boundary it is highly burrowed and5 _ __. 4— j SMEAR SLIDE SUM M ARY <•> ~ '~~' L~HjL~ 1" * π\πl ' P° S ° PVn e enπc men are common, an re ar gray

_ _ Qs JU L U I 2 80 3 70 S ~ri, ~, ^– Ll_ _i_" D D * ^? I 1 SMEAR SLIDE SUMMARY

I CG l β ~ ^ ^ 1 _ l J _ * * fVrtte 1/T 1/T ' " ~ r l = = 1 , , . 1 . ! . 1 80 " 3 7« r•-×J~ . _1_ Clay minerals 18/C 20 /C 2 CG " - O L i ~ L i O D DI " "_-:: = " * - _ ! _ Volcanic glass (It) - 1/T ^ - - . . " * " , Pvrite 2/R - 2/RI --lO'-1-,-1-' Carbonate unspec. 10/C 10/C I - r. ~j£ " j _ X J . Clay minerals 8/C 14/C 15/C< _ r - : = - _ ! _ , _ ! _ - r ~ 5 G 6 / 1 Foraminifers 1/T - E jg . ^– ^ - J _ - - - _ J _ Volcanic glass (dk) - 1/T -

« • - I - f •^ - • jL . - 1 - . ! - ^ 5G6/1' Calcareous nannofossils 50/A 35/A <t ri IT : " 1 J . Carbonate unspec. 15/C 10/C 10/CS _ - _ j v -l_ •« 5Y6/3; Dia,Oms 10/C 15/C " r, O . _1_ « _ Foraminifers 3/R 5/C 1/T

S d X ,-L- * * 5 Y 7 / 3 • Radiolarians 5/C 10/C E = = - • - j , - 1 - = 5GY6/1, Calcareous nannofossils 50/A 45/A 50/AI ' -I-O ^~X.-1- «< N 4 Silicoflagellates 5/C 8/C " IT Λ U . , _L 5G 6/3, N5, Diatoms 10/C 12/C 10/C

g I C " ; : ' ! _ | I " ~ _ 1 _ _ L 5Y8/3, Radiolarians 4/R 7/C 4/R8 .2 CG H Q J T J L CARBONATE BOMB: " ^" > ! _ J . L _J . 2 5YW3 Silicoflagellates 8/C 6/C 8/CS S " – • . I ^ ^ 1 19 cm = 63% 2 19 cm 42% 3 19 cm = 62% g _ IT " W. _ ! . • • <2 I _: X• J i 1 49cm = 56% 2 49cm 44% 3 49cm • 55% .2 F M

ü H F S JL. S<K CARBONATE BOMB:- S ~ r ] v -L-_J_-1- " 5G8/1, 1-73 cm = 47% 2-79 cm - 57% S _ ^ K > "^-L-~1" ~~ ~ 1-19 cm = 53% 2-49 cm = 40%

? 2 " 3 = : ""-r-1- 5GY8/1, M09cm = 48% 2-109cm-47% S t 2 " " _ - -L- - i - ' 1-49 cm-5196 2-79 cm - 42%I " -4Q '-L- , - I - ' * 5 Y 8 / 3 1-139 cm = 34% 2-139 cm = 68% ~ S " T. A -l~~~J- 5 G Y 8 / 1 1-79 cm = 53% 2-109 cm = 43%§ • _ EH- - _ i _ - J - _ l _ I - - I ~^~ • _ | _ _ 1 _ 5Y8/3 1-109 cm = 51% 2-139 cm-48%

_riIX-,-'-_, - _ - CARBONCARBONATE: 42, CC .0 _ - Z = • , ->- , BY 5/3! 1-139 cm = 51% 319 cm- 54%t CG - ^ ‰ • \ - * - ! 5 G 6 / 1 • % Carbonate 18 5 . H O T " ' T 5 Y β / 1 2 19 cm = 41% § j j j I _1_ . 5 Y 7 { 3 • % Organic carbon 0.4 "J CG " = = L I " " jθ f l _ . _l _ β®< _ 5Y 7/1 O _ ^ _ _ 1 _ J _ CARBONCARBONATE: 43, CC3 „ H U J _ J . – 5 G 8 / 1 , : : > C J _ 7 L . % Carbonate 42I ^ 4 * 1 X* 5GY8/1.5Y8/3 S E:' ~ _ 1 _ J _ % Organic carbon 0.4"ò. 00 - H ^ ' _L_ . "> -– j**— ~ ^ ' ~u " --"cf - 1 - . --- ~ KVH/ J = • S - V ^ j _ J_ , 5Y8/1,

- H & J I ÷ J-• M?»2.BGYβ/i i :=λZ i i: L: 5 G Y 8 / 1

: Bfc j > ÷ : - - 5G6/1, I 3 - i = ^ : - 1 - ^ ^ ,._ f> r_"t - " " I 5G 5/1 S. oβ ' • J \ _ " _• 1 5Y 8/3,I FM 1=3 : ^ è ^ 6/3• f c • î î • ± ± : "• *"• 1 E=zL ^ i : : ^ ^ ~ VO,D ™CM AG s C c | T y ^ L ^• i 1 1 ^ > β / 3a S '• ~~ T* • 1 ~ 1 5G4/ 1.5Y4/ 1, £</j ^• _ r_ ~ ' _L L " _ N7,2.5Y 7/2 | | | | | | | •~ ] |

RM FP AG C C ] " > - - y j J ÷ • X - l 0 ! 1 ' 5G 8/12 Note: Graphic lithology represents average composition derived from

types. Gradational changes between smear slides are arbitrary and donot imply actual lithologic trends. Color variations approximate litho-logic changes.

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5Y8/1

—5Y8/ 1,5G8/1,5G 7/1,5Y7/2

—5Y 6/1,5GY6/ 1,5Y 6/3,5Y5/3

_

5GY8/1,

5G 6/3]5Y4/1

—

5Y 7/2'5G7/ i!5Y 6/3,5G 6/ 1,N3

_

5Y8/ 1,5G8/ 1,5Y 8/3,5Y6/1

5Y 6/2,5G6/ 1.N5


Cyclic alternation of SILICEOUS NANNO OOZE AND SILICEOUSNANNO MARL ranginggreenish gray (5G 8/1 a

in coled 5GY

greenish gray (5G 6/ 1). Gradatiois highly burrowed and mottledSpots and streaks of pydeformation structure refrom 20 cm in Section 1

rite enrated too 5 0 c m


PyriteClay mineralsCarbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSilicoflagellates

CARBONATE BOMB:1 19 c m 5 6 %1 49 cm = 38%1 79 cm = 40%1 109 c m 5 3 %1 139 cm =52%


2 30D2/R10/C10/C 50/ A18/C5/C5/C

2 19c2 49 c2 79 c2 1092 139

44.CC37

0.4

5>

r from yellowish gra8/1) to light olive gr

TroughouLCoirrTchment are commonHPC coring is in the cin Section 2

2 100D3/R15/C10/C2/R40/A20/C3/R7/C

•n = 33% 3 19 c•n =• 43% 3 49 cT i . 41% 3 79 ccm = 47%cm = 53%

y (5Y 8/1) andy (5Y 6/1) and

ngâr^^btlë1

A "collapsed"nter of the core

m - 52%m = 66%m = 35%

SITE 503 HOLE A CORE (HPC) "6 CORED INTERVAL 195.4-199.8 r

SITE 503 HOLE A CORE (HPC) 45 CORED INTERVAL 191.0-195.41

TIM

E -

RO

CU

NIT

late

Mio

cen

X

BIO

STR

ATIG

RZO

NE

3

FOSSILCHARACTER

I

vca

datu

m (D

)

ES;

JS<

1AM

1 jCG

SUB-

BOTT

OM

SEC

TIO

N

CC

MET

ERS

GRAPHICLITHOLOGY i 3


No core recovered. (Biostratigraphy based upon sediment streaksfrom Core-Catcher.}

i_ LITHOLOGIC DESCRIPTION

SILICEOUS NANNO OOZE. Thspots of pyrite enrichment.

SMEAR SLIDE SUMMARY

PyriteClay mineralsCarbonate unsForaminifersCalcareous narDiatoms

1-140DI/T11/C

Dec. 10/C2/R

inofossils 50/A18/C

SITE 503 HOLE A CORE (HPC) 47 CORED INTERVAL 199.8-204.2 r

IE -

RO

CU

NIT

1

(a) 1

11

1

RA

TIG

R;

ZCN

EBI

OST

sj;

rr•i

0

FOSSILCHARACTER

z

|

s1•3.Sj

È

1J?

CM

0

z

AM

1

<s1

\CM

Σ

1

iso>

00.0

2

CM

§

I 20

1.1

iEC

TIO

N

1

cc

WET

ERS

1 . 0 __

GRAPHICLITHOLOGY

= — _ 1 _ 1

VOID

<>

‰ r

1 1

^ ^

_ 1 _ _ 1 _

L _ _ 1 _1 1

1—* 1 ~1 _i_ _L

L 1 ~*~ 1I _ 1 _ L _ L

I— L

1 _ 1 _ L _ 1 _u_i_ i _1_

Aú00

0000

0

111


SILICEOUS NANNO OOZE in various shades of gray (N6, N7). Uni-form in color except for a spot of pyrite enriched at 15-20 cm inSection 2, grayish black (N2) in color.

SMEAR SLIDE SUMMARY1-120

N8, N7 DPyrite 2/RClay minerals 8/CCarbonate unspec. 10/CForaminfiers 2/RCalcareous nannofossils 50/ADiatoms 20/CRadiolarians 5/CSilicoflagellates 3/R


types. Gradational changes between smear slides are arbitrary and donot imply actual litholσgic trends. Color variations approximate litho

SITE 503 HOLE A ÇQRE (HPC) 48 CORED INTERVAL 204.2-208.6 m

E-R

OC

UNIT

IMI

0 )

iocen

S

—

o

1

IATI

GR/

ZONE

1 -

g

——

•II1a

_á^ £

SJ"* i„ ε• s s

11I 4it

sIs

Itin

<δ

o

CM

FOSSILCHARACTER

1z

NAN

CM

z

o

é

CM

CM

o

I

CM

TTOM

I

Is

204.

8

i.86

S"

o

o

7.65

1 20

7.85

20

l -

0 0

1

2

3

CC

lETE

RS

2

-

_

-

1.0 —

_—_

-

-

--

GRAPHICLITHOLOGY

JL."1"-!-'

VOID

_ _

r- =

r~~—wr7 =

m

^ =^ =

•ZA.j— -

>1=o

j - z

- ^ _

_l_~j~-l_

UI-KJI•_L_ - L -

- t ~^~ 1" ' ~ ^ 1 .'

~ i ~ ^ i ~- , — 1 - , •

J— .

I j_- 1 - 1 — i

- ^ —>—, .i

- L - _ 1 _ - L -

_ i _ JL.

*_ l _ _L_

^ ~ i • 1 "~*~ i—i— i—^—_ 1 _ l

BANC

EDR

ILDI

ST

oo

•-N.

KW

*


5G 8/1, Cycles of SILICEOUS NANNO OOZE showing subtle color variation10YR 8/3 downcore ranging from light greenish gray (5G 8/1, 5GY 8/1) and yel-

~~ lowish gray (5Y 8/1) to light greenish gray (5G 7/1) and yellowish gray(5Y 7/1). Areas of pyrite enrichment are common yielding darkeishades to the basic colors. Burrowing and mottling are common

lyl1/]' SMEAR SLIDE SUMMARY5GY8/1, 2 • 8 0

N5, N3, D5G 7/3 Clay minerals 13/C

Carbonate unspec. 10/CForaminifers 2/RCalcareous nannofossils 50/ADiatoms 15/CRadiolarians 5/CSilicoflagellates 5/C

— CARBONATE BOMB:1109 cm = 77% 2-79 cm = 73%

5Y8/1, 1-79 cm = 75% 2-109 cm = 73%5GY8/1, 1-139 cm = 79% 2-139 cm = 66%lf*8'\ 2-19 cm-78% 3-19 cm-75%N5, N3, n5G 6/3, 2 m c m ~ 7 5 % 3 ' 4 9 c m 7 4 %

5Y 5/3'CLAY MINERALOGY (<2µm): 2-74 cm

.. Smectite 100%VOID


5G7/1,5Y7/1,5Y 8/2,N5,5Y8/1

5G8/1,5Y8/1 ,N7.5GY8/1,5G 7/3

SITE

8^

TIM

EV0

S

—

503 HOLE0

1

ATIG

R>

2CN

EBI

OST

R,

1

|ft<á

penu

ltii

d

FOSSCHARAC

YIFE

RS

i

s

•9

FM

I|

CM

z

|

CM

A CORE (HPC)LTER

sCG

0—(O

S

B0

1.39

CTI

ON

1

2

CC

ETER

S

0.5 —

1 . 0 -

-

-

™

-—

~—

-I-

I1!

Ij

-–~—

-

-:


GRAPHICL ITHOLOGY

—\.

—\_

^Z-- i _

^ . •

cP

L ->-i

L. _ l__ 1 _ _1L_L. J M

L.-•-j.-1

-J-T-1

'~-L-~l~-L' 1 1 1

1II1

SJ

*

•


VOIDCycles of SILICEOUS BEARING NANNO OOZE which darkenstoward the base of the core. Colors vary from light greenish gray {5G8/1) and yellowish gray (5Y 8/1) to dark greenish gray (5G 4/1) andgreenish gray (5G 6/1). Numerous spots and streaks of pyrite enrich ment occur which are medium gray (N5) to dark gray (N3) in color.

5G8/ 1, Highly burrowed and mottled.5Y8/ 1,5G7/ 1, SMEAR SLIDE SUMMARY5G6/ 3, ,..,25 c c 1 2

N7.N6, „ „5Y7/ 3 D D

Pyrite 1/T 2/RClay minerals 15/C 12/CVolcanic glass (It) 1/TCarbonate unspec. 10/C 10/CForaminifers 1/TCalcareous nannofossils 50/A 50/ADiatoms 15/C 15/C

. _ . . . Radiolarians 5/C 3/R5Q6/ 3; Silicoflagellates 3/R 2/R5Y 8/ 3,4/ 1,N7 CARBONATE BOMB:

1 49 c m 72% 1 139 cm = 78%5G 6/ 1, 8/ 1, 17Q rm — fiQ% 9 1Q rm — R7°/5 Y6 / 2 . _5 G7 / l . 1 1 C ] 9 c m = 7 3 %


: Graphic lithology represents averr slides and does not reflect the dii, Gradational changes between sm

changes.

SITE

1 Z

I

cgi

late

503

£| |£ N

o

—

I

_j :

•ft*

ICi

£I

j .

_

f

i

FOR,

RM

H O LE

FOSSCHARAC

o

z

CM

I3

I RAD

I

CM

CM

A CORE (HPC)LTER

o

s

CG

CG

tAG

g •

?CM

!

CG

I217

:TIO

N

1

2

CC

TERS

S

0.5 —

1.0 —_

—

_

—

50 CORED INTERVAL

GRAPHICLITHOLOGY

: v : ^ \ ^

1 ^

= =<

O1

_ _ _

_= — — ^

= —0

= =

^r :

^}_/

ft/~\_. _cfcf• ^

\ J~

~"T~" j

t L | l_ J

L _1 _ J j

α_~(~ i_~

L _ 1 _ L " i_ J_1 * 1 ~, — 1 — , —

i

i>± :XT L."

i ~ 1 "

i i " *

J 1

"L~_j_—*—_jJ . . _ 1 _1 1

"L ~l~ J JIT • L.J _1_ L j

1 ~ 1 " 1 ~1 ~ ^ ~ 1 " "

^ . L .

^ ' _] 1 — _L

* 1 _J_

"_1_ _L"j ~J

" 1_ J.

1 _1_ L•

0z

IsSo

01

110

z

fi

(«^

—

iVOID5GY8/5Y8/35G8/15Y 8/1

N4, N5N7'

_5G7/15GY8/5G6/1N7,5Y8/1

—

5Y8/35Y7/35G 8/1

2 1 3 . 0 2 1 7 . 4 m


1, Cycles of SILICEOUS NANNO OOZE,antly light greenish gto dominantly lightment is highly burrcstreaks are commonlonitel?) are at 33 a

ay (5GY 8/ 1, 5G 8Dlive gray (Ewed and mSpots enr

id 109 cm


Pyrite1, Clay minerals

ForaminifersCalcareous nannofossDiatomsRadiolariansSponge spiculesSilicoflagellates

CARBONATE BOME5GY8/ 1. 1 19 cm 50%5G7/1N7

5G7/15G8/15Y6/3

5Y6/25Y5/35Y5/15G6/35G7/1

5G7/15Y8/15Y6/5

1 49 cm = 53%1 79 cm = 62%1 109 cm = 67%1 139 c m 4 8 %

2 115D1/T10/C10/C1/T

Is 50/ A15/C8/C2/R3/R

:2 19 c2 49 c2 79 c2 1092 139

CARBON CARBONATE: 50 , CC% Carbonate% Organic carbon

230.3

Y 6/2)ott ledched inn Secti

3 7M2/R25/ A8/C

35/ A15/C12/C 3/R

•n 50°/Ti 58°/

•n = 565

cm = 65cm = 59

anging in color f/1) and pale yelloand olihroughgreen

' " ! a n

3 85D1/T14/C10/C

50/ A15/C7/C 3/R

%%

re (5Y 5/3out. Pyrite(5G 4/3)

d 12 cm in

3 19 cm =3 49 cm =3 79 cm =3 109 cm

om do« (5Y. Thespots

montmSectio

38%39%

44%

• niπ8/3)edi andoril n 3 .

SITE

IME

RO

CU

NIT

c

I5

5 0 30

STR

ATIG

Rj

ZON

EBI

OI

_

S5

1δ

|

1

(R)

11ci

z

O

RM

HOLE A CORE (HPC)FOSSIL

CHARACTER

1z

I

CM

CM

CM

I5

AG

Is

217.

40

t o

0CN~

»

ss

220.

SEC

TIO

N

1

2

3

CC

MET

ERS

0.5 —

1.0 —

•

_

_

5 1 CORED INTERVAL 217.4 221 .8 m

GRAPHICLITHOLOGY

~—\ J\ —_/ \

—

—\~l

—**j

t

<

^ =

J _ JL.

J _ _L_

J— J—i i j ~ ^

—'— J

~ i— i . 1 — —L._ 1 _ _L

VOID

1 J __ 1 _ . _L

_L LJ_ L

_ I _ J __ J _ L_

(~üJ-L- 1

bRIL

DISTl-o-

|

i

D IC

ZΛ •

« « .

I

*

N6,5G6/ 1.5Y 6/ 1,5G 7/ 1,5Y5/ 3

5G8/ 1,5G7/ 1,5Y8/ 1,5Y 8/3,5G6/ 1,5Y6/ 3

—5G7/ 1,

N7 5Y 4/1

5G 4/2, 5Y 4/ 3,5G 6/ 1, N7.N5

5G 8/ 1,5GY8/ 1,5Y8/ 1,5G7/ 1,5G6/ 1

5G 6/ 1,2.5Y 6/3,N4

5G 4/3, 5Y 5/4,5Y 7/3, N3


Cycles of SILICEOUS NANNO OOZE, ranging in color from dominant ly light greenish gray (5G 8/ 1,gray (5Y 8/1) to dark grsediment is highly burrcments are common as wrichments

yish gr5G 7/ 1, and 5GY 8/1) and yellowisheen (5G 4/2) and olive (5Y 4/3). The

wed and mottled throughout. Pyrite enrich ell as g


PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.


CARBONATE BOMB:1 49 cm = 67%1 79 cm = 58%1 109 c m 63%2 19 cm = 23%


2 20D1/T8/C1/T10/C

50/A15/C10/C5/C

249 c2 79 c2 1092 139

51, CC29

0.4

een (5G 4/3) montmorillonitel?) en

2 60 3 16D M1/T6/C 22/C_ _10/C 10/C

50/A 40/A15/C 15/C8/C 8/C5/C 4/R2/R

m 64%m = 54%cm 56%c m 5 1 %

51, CC54

0.2

erived frorrot sedimemrary and de

SITE

ME

RO

CU

NIT

1i

—

503oI

TRAT

IGR

/ZO

NE

j BIO

S

_

berg

gren

i (ts

Q

§I1j

(U)

1

HOLEFOSS

CHARAC

z

H

RM

o

1

CM

FRAD

I

CM

A CORE (HPC)LTER

%

|θ,A

T

AG

j SUB

BOT

TOM

221.

80

ss

SECT

ION

1

2

3

CC

MET

ERS

0.5 —

_

1.0 —

_


GRAPHICLITHOLOGY

~ ^~

I II jr_ _ I 1

~—

5:I I 3 ~_r Z " 3 _ _rt

I I

>;_

> :

I ::

er S\^ :_r\

• ‰ . .

_r\ KS

j— *

~wO\ v y1= *^0<>

:

—\_r=

l _

~" *"

ZÀ

t— =

=—/ _

_ i

~ i_ -J_

_ —L.

- i _ ."J— -

1

_ i-1— i -JL. .

1

- • - J J •

- ( * ~

: ^ •

^ •

; |

3 QQ CC

ΦΦ :

©«=

© ® ^

–

8

i

*


| Y 8/ 1' cVdes of SILICEOUS NANNO MARL, ranging in color from light5G 6/ 1! greenish gray .(5G 8/ 1, 5GY 8/1) and yellowish gray 15Y8/1) to green 5Y 7/3'. ish gray (5G 5/ 1, 5G 6/ 1, and 5GY 6/1). Spots and streaks enriched5G 6/3, jn pyrite are common. Some burrows have reaction rims of pyrite.5GV6/ 1 Highly burrowed and mottled.

SMEAR SLIDE SUMMARY1 80 2 120

_ D D5 Y 8 / , Pyrite 1/T I/T5 G8 / l ! Clay minerals 21/C 22/C5G 6/1 Carbonate unspec. 10/C 10/C

r Foraminifers 3/R 2/RCalcaeous nannofossils 35/A 40/A

5GY6/ 1, D i a t o r m 15/ c 15/C5Y 6/ 2! Radiolarians 10/C 5/C5G7 / i ' Sponge spicules 2/R

Silicoflagellates 3/R 5/C

6 Q 8 / 1 CARBONATE BOMB:5Y8/ i ' , 1 19 cm = 58% 2 49 cm 64%5GY8/ 1 1 49 cm = 47% 2 79 cm = 44%

1 79 cm = 56% 2 109 cm = 58%_ 1 109 cm = 50% 2 139 cm = 75%

5Q$/ 1 139 cm =50% 3 19 cm = 71%5G 6/2! 7/ 2, 2 19 cm = 56% 3 49 cm 56%5Y6/ 1,N 3 • N 5 • CARBON CARBONATE: 52, CC

_ 5 G 7 / 4 % Carbonate 26% Organic carbon 0.4

5G8/ 1.5Y8/ 1,5GY8/ 1,6G7/ 1

5G6/ 1,5G7/ 1,5Y 6/ 1,N6, N4

SITE 503 HOLE A ÇQRE (HPC) 53 CORED INTERVAL 226.2-230.6 r

\Ljt-:


5Y8/1,5G8/1,5G 6/2,5Y 7/3,

5G6/1,5Y 6/3, IM6,2.5Y 6/3

5G7/1,5Y7/1 ,N5, N3

SILICEOUS NANNO MARL, ranging in color from domingreenish gray (5G 8/1) and yellowish gray (5Y 8/1) to gre(5G 6/1) and pale olive (5Y 6/3). Spots, streaks, and zonesenrichment, dark gray |N3) and medium gray (N5) in colormon throughout. A carbonate nodule, formed around a bu12 cm in Section 2. Entire core highly burrowed and mottled.

ntly lightnish grayof pyrite

Clay mineralsVolcanic glass (dklCarbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSilicoflagellates

CARBONATE BOMB:1-19 cm = 42%1•49cm = 44%1 79 cm = 47%1-109 c m - 19%1-139 c m - 37%2-19 cm = 43%

CARBON-CARBONATE:% Carbonate% Organic carbon

28/C1/T10/C_30/A15/C10/C4/R

2-49 er2-79 er2-109 (2-139 <3-19 er3-49 er

03, CC24

0.2

21/C-10/C2/R35/A12/C10/C3/R

n = 44%n = 43%;m = 38%:m = 38%n = 33%n = 33%

Note: Graphic Hthology represents average composition derived fromsmear slides and does not reflect the detailed alternation of sedimenttypes. Gradational changes between smear slides are arbitrary and donot imply actual lithologic trends. Color variations approximate litho-logic changes.

NJOOO

SITE

;

RO

CK

JNIT

TIM

! I

03

c

_oj—

5 0 3u

ATI

GR

AP

HZO

NE

BIO

STR

(NI

1CS

1α

—

I

HOLE A CORE (HPC) 54

FOSS LCHARACTER

— 1

_

RM

Iz

CM

!

RAD

IOL

CM

CM

CG

!0

DIAT

OM

AG

h\ l

3oo

32.1

1

8

ss

i 23

4.75 ;

ACTI

ON

1

2

3

CC

lETE

RS

5

0.5 —

_

1.0 —

_

CORED INTERVAL 230.6 23S.0m

GRAPHICLITHOLOGY

Z Z Z I I I I-ü-I-:-_r_~_

-_~_7~__"_7_T- _ - _ - !-_-_-_-_.-_-_

:_SS_-_:_:___r_z__ _ _ _ __n__.~_~_r_r_-_-_r_7

:___:-:_r_r_:_£?_-_v-l-I-_7_T_:

_ _"_r:__r_r:J_~__Tr_~_r_•_n_~_.•

_r_r_rX-I

II

I

~ :÷zz

j' j

I j

1' 1

' 1i!

i!

i

~_r_r_:

sî-_—.: =

= =_i"\_— _ / -

Z —

r_.

=

- —-T\_- < _ — •

- —

_-C_~___Λ _

" * _"= \^ ^_ _/

o

_ —o

r_

• * ~ J .~ _L _—' i

"~ i.

~ — •

JL~. |JL

" X

1

—*

~ _

• ~ 1

J ~ __

1

—L

• •

**~ j

_L" L~* |~ |

—L~ i .

_—*"_ ^

_

—i_ ÷-_

o

8

1

NTAR

YUR

ESI S

TRUC

T

_ -

i

2S-–

-–

f SAM

PLE

*

*

N7,5G6/1,5GY6/1,5Y 4/1,5Y 6/3

5G5/1,5Y8/1,5G4/15G 2/2.6/1,2.5Y 5/3

5G 6/1, 7/1,N7, N5,5G4/3

N7, 5G6/1,5GY6/1.5B7/1

5Y7/35G8/1.5B7/1,5G 6/1,2.5Y 7/2, 7/3,N6, 5G 5/3

5G 6/2,2.5Y 4/2,5GY6/1,5GY7/1

^6G7 /1 ,5Y7/1

6Y 7/2, 5Y 8/3,BY 8/1, 5G 8/1,

- 6G 7/15G7/1.5G 6/1.N3, N6,5Y 6/3,6GY8/1,5G6/3

N8, 5G8/1,5G 7/3,2.5Y 5/2, 7/2

5Y 6/1, 4/1,5G 6/1, 6/3,

— 5Y B/15GY 6/1


Cyclic alternation of SILICEOUS MARL, which is light gray (5Y 7/1)and light greenish graySILICEOUS-BEARINGGradations in both colo

5G 7/1) in color and CALCAREOUS AND:LAY, greenish black (5G 3/2) in color.

and composition between the endtypes arecommon. Streaks and spots of pyrite enrichment are common, darkgray (N3) in color. Entire core highly burrowed and mottled.

SMEAR SLIDE SUMMARY

PyriteClay mineralsCarbonate unspec.Calcareous nannofossilsDiatomsRadiolaπansSilicoflagellates

CARBONATE BOMB:1 19 cm = 34%1 49 cm = 30%1 79cm= 10%1 109 cm = 50%1 139 cm = 35%2 19 cm = 53%2 49 cm = 41%

CLAY MINERALOGY USmectite 100%


1 77 2 110D D1/T 1/T59/A 34/A10/C 10/C5/C 25/A10/C 15/C10/C 10/C5/C 5/C

2 79 cm = 38%2 109 cm = 59%2 139 cm = 50%3 19 cm = 51%3 49 cm = 47%3 79 cm = 51%

2 m) : . 2 71 cm

54, CC50

0.2

SITE 50 3 HOLE B CORE (HPC) 1

Note: Graphic lithology represents averasmear slides and does not reflect the detypes. Gradational changes between smenot imply actual lithologic trends. Colorlogic changes.

CORED INTERVAL 0 . 0 2 . 8 m


VOID

10YR5/4,10YR6/ 4

Cyclic alternation of IRON OXIDE AND SILICEOUS BEARING CAL CAREOUS OOZE, which is very dark grayish brown (10YR 3/2) incolor and SILICEOUS BEARING CALCAREOUS OOZE, which isyellowish brown (10YR 5/4I to light yellowish brown (10YR 6/4)

rowed or gradational. Some mottles are pale yellow (5Y 7/3) in color.

10Y.R 3/2

10YR 5/4.10YR 6/4

Amorphous iron oxideClay mineralsVolcanic glass (dk)Carbonate unspec.


CARBON CARBONATE:

% Carbonate% Organic carbon

—15/C2/R15/C8/C40/A10/C7/C2/R1/T

1 1 en73

0.2

10/C23/C2/R20/C_30/A8/C7/C

1 1.1

26

5/C15/C 20/C10/C30/A8/C7/C3/R2/R

X

0.5

10YR 6/4,10YR 4/ 3,10YR 3/2

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GRAPHICLITHOLOGY

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r_ ~• £ rjr

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— VOID10YR 3/2

10YR 5/4.10YR 6/3

10YR 6/ 4

10YR 4/ 3,10YR 3/ 4.10YR 6/4

10YR 8/ 3,10YR 7/ 3

1 0YR4/ 3 ,10YR 3/4

~ 1 0YR3 / 3 .10YR 7/3


Cyclic alternation of IRON OXIDE AND SILICEOUS BEARINGNANNO MARL, which is very cyellowish brown (10YR 3/4)

ark grayish brown (10YR 3/2) to darkn color, and SILICEOUS BEARING

NANNO MARL, which is very pale brown (10YR 8/3 and 10YR 7/3)in color. Gradations in color and sediment type are common. Bur rowing and mottling are common. Open burrows are present at 112 116 cm, Section 2.

SMEAR SLIDE SUMMARY1.70D

Amorphous iron oxide 5/CClay minerals 23/CVolcanic glass (dk) 2/RCarbonate unspec. 15/CForaminifers 10/CCalcareous nannofossils 25/ADiatoms 10/CRadiolarians 8/CSponge spicules 2/R

CLAY M INERALOGY (<2 m)Smectite 85%Chlorite &

Kaolinite 15%

CARBON CARBONATE: 2. CC% Carbonate 70% Organic carbon 0.1

2 120D10/C25/A_15/C10/C25/A10/C3/R2/R

2 71 cm

SITE

/IE -

RO

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GRAPHICLITHOLOGY

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_ 10YR3/ 3'

10YR8/3

_ iOYR 3/3

10YR6/ 4

IOYR 3/ 3.IOYR 6/ 3,10YR 5/ 3

5Y6/3

5Y 6/3,5Y 5/4

5G 5/ 1,5G 4/1

_ 5G 7/ 1'

5GY7/1

5GY 6/1

~ 5GY5/ 1,5GY 6/1

5G 4/ 1,5G5/1


Cyclic alternation of IRON OXIDE AND SILICEOUS BEARING CAL CAREOUS OOZE which is daSILICEOUS BEARING M ARL,to light yellowish brownsediment type are presen

10YR) over

BEARING NANNO M ARL, darish gray (5G 7/ 1) in color.throughout the core. Op85 105, and 120 135 c

oxi ize an re uce sect

en bu" i n S

onsis

SMEAR SLIDE SUMMARY

Amorphous iron oxide

Volcanic glass (dk)Carbonate unspec.Foraminifers

DiatomsRadiolariansSponge spiculesMicrite (C03)

Clay mineralsVolcanic glass (It)Volcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellates

CARBON CARBONATE:% Carbonate% Organic carbon

1 50D3/R

20/ C2/R15/C15/C30/ A8/C5/ C

2/R

3 30D27/ A

2/R20/ C1/ T

30/ A7 / C8 / C2/R3/R

3, CC320.3

rk brcwhich6/ 4) iyinggreer

3urro»rowsction

at 1

1 70D10/C

20/ C20/ C25/ A8/C5/C

3 90D25/ A1/ T

2/ R

20/ C

30/ A10/C10/C

2/ R

wn (10YR 3/ 3) in color, andis very p ale br

n color (gradatolor varish graying andre tounc

ations

jwn (10YR 8/3)ons in color andof SILICEOUS

5G 4/1) to light green mot t lat 7,

2. A sharp concm in Se"*'' '"

2 20D

3/ R

25/ A10/C25/ A8/C7 / C

2 63M

2/R35/A2/R20/C1/T10/C2 / R

ng are common32, 45 57, 64,act between the

2 120D

20/ C

15/C10/C20/ C3/R10/ C2 / R

20/ C

SITE

z

TIM

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cu

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503

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GRAPHICL THOLOGY

Z ~ I I _ _rjrjrr T Z Z

z z ~Z Z z z

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5G 7/1—

5G 8/1and N7

5GY 5/2

5G 5/2,5G 6/1

_

5G 7/1.5 G 6 / 1 ,5G 8/1

5G5/1

5G5/1,

5G7/1,5G4/1,6GY 6/1

5G8/1,5G 7/1

5G6/1,5G5/1

5G 5/1,5G 4/1


Cycles of SILICEOUS-BEARING CALCAREOUS OOZE, with colorsranging from very dark(5G 8/1). Burrowing andburrows are common inSection 3. Some burrowcarbonate, occur at 143 c

greenishcolor mthe low

s are pym, Secti

SMEAR SLIDE SUMMARY

Other heavy mineralsClay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellatesMicrite


1-110D

30/A2 / R

25/A7/C20/C8 / C

8 / C

-

4, CC41

0 . 3

gray IDttlinger halfritizedDn l.a

2-52M

1 / T

24/C1 / T

30/A2 / R

10/C10/C12/C2 / R

1 / T

10/C

5G 3/1are comof SecBurrovd36c

2-121D2 / R

22/C2 / R

30/A4 / R

10/C12/C8 / C

-

10/C

to tight greenish graymoπtion 2

vs, semn. Sect

3 30D

32/ A1/T20/ C2 / R

25/ A8 / C

12/C

roughout. Openand at 95 cm in indurated withon 2.

3 80D

1/T25/ A2/R20/ C ,5/C20/ C7/C7/C .2/R1/T10/ C

Note: Graphic Hthology represents average composition derived fromsmear slides and does not reflect the detailed alternation of sedimenttypes. Gradational changes between smear slides are arbitrary and donot imply actual lithologic trends. Color variations approximate litho logic changes.

NJO

SITE 5 0 3 HOLE B CORE (HPC) 5 CORED IN TERVAL 1 6 . 0 2 0 . 4 m

5G 6/ 1,5G 8/ 1,5G7/ 2

SITE 5 0 3 HOLE B CORE (HPC) 6 CORED INTERVAL 2 0 . 4 2 4 . 8


Cyclic alternation of SILICEOUS BEARING MARL, which is lightgreenish gray (5G 8/1 and 5G 7/11 and dark greenish gray (5G 4/2and 5G 4/1) in color, and CALCAREOUS SILICEOUS MARL, darkgray (N3) and medium dark gray (N4) in color. Gradations in color

tized burrows are common. A carbonate nodule, light gray (2.5Y7/2) in color, which formed around a burrow is at 38 cm in Section

33/A 38/A 26/A

e: Graphic lithoiogy represents avera>ar slides and does not reflect the det

imply actual lithologic trends. Colorc changes.

CarbonForamiCalcareDiatorrRadiol;Sponge

ate unspec.nifersous nannofossilssiriaπsspicules

2C ?.7/C10/C5/C5/C_

25 A2/fi5/C8/C8/C1/R

;c c_5/C12/C15/C2/R

I/T 1/R 3/R20/C 10/C 10/C

CLAY MINERALOGY (<2 m): 2 71 •

CARBON CARBONATE: 5, CC

E

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GRAPHICLITHOLOGY

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5G7/ 1,5G 6/ 1,5GY 6/2,N4,N7,5G 5/2

—6/1

5G 6/1

5G 6/ 1,5G5/ 1

5G7/ 1,5G 6/2

5Y 5/2,N3

5Y 6/2,5Y 4/ 2,5GY 6/2,5GY 5/2,5G 6/2.2.5Y3/ 1,2.5Y 5/1

~ 5G 7/2,5G6/2

5GY 5/3,5G5/ 1,5G7/ 1

5G 5/3,5G 6/1

5G7/ 1,5G6/ 2

5G 5/1


Cycles of SILICEOUS BEARING MARL, ranging from gr(5G 5/2) to light greenish gray (5G 8/1) in color, with semottles, of very dark grcommon. Zoophycus burSection 2, and 8 23 errand 145 153 cm in Secritized burrows and zones

ay (2.5Y 3/1)rows a

Burrowing and me at 122 cm in Section 1,

in Section 3. Open burrows areion 2,of pyri

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (dk>Carbonate unspec.

Calcareous nannofossilsDiatomsRadiolariansSilicoflagellate^Micrite


1 110D

2/R25/A2/R15/C3/R12/C 10/C

6, CC28

0.3

25, 56eenric

237D8/C

2/R ,25/A2/R10/C10/C10/CI/T10/C

and 83 cm in Secment are common.

3 50D2/R

2/R20/C

20/C12/C12/CI/T10/C

yish greenme darkerottling are143 cm inat 45 52

tion 3. Py

SITE

ME

R

OC

UN

IT

H

C

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5 0 3

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1.0 —

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CORED INTERVAL 2 4 ;8 2 ft2 m

GRAPHIC y

LITHOLOGY

—

jr. Jr jr.J~ •

Jr

JT—.~JT JTJT.

~JTJ

JTjrSJ .

j j~jrz

~J JJTJ .

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I I JTJ

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N5,5G7/1,5GY 5/2,5GY6/1,5G 6/2

.— 5B 6/1'5G8/1,5G6/3

_5B6/1,5Y4/1'

5Y 3/2,5Y 4/2,5Y3/1,5Y7/2

_5GY 6/3,5G 6/3

5G4/1,5G7/1

5GY 6/2,5G7/1,5G 5/1

5G4/2,5G5/2

-N3

5G 5/2,5G4/1,5GY 5/1


Cyclic alternation of SILICEOUS-BEARING CALCAREOUS OOZE,dominantly light greenish gray (5G 8/1) in color and SILICEOUS

color and sediment composition are cmotlting are common. Aand an open burrow is abands of pyrite enrichm

zoophycus burt 68 cm in Sent (grayish bl

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (It)Volcanic glass (dk)Carbonate unspec.Foraminifers

DiatomsRadiolariansSilicoflagellate!Micrite

CLAY MINERALOGY (•;Smectite 96%Chlorite &

Kaolinite 4%


5G 6/2, 5G 5/2

5G 7/2

zz N2.N5

5GY6/1,5Y4/2

1-90 1108D M-24/C 90/D-1/T -15/C 10/C15/C -15/C -5/C -10/C --15/C -

2µm): 2-71 c

7,CC340.5

mmon. Burrowing and colorow is at 130 cm in Section 1tion 3. Pyritized burrows andck [N2] and dark gray [N3]

3-20D1/T29/A2/R2/R15/C

10/C12/C12/C2/R15/C

m

SITE 503 HOLE B CORE (HPC) 8

vlote: Graphic lithology represents avera,mear slides and does not reflect the de-:ypes. Gradational changes between smeiot imply actual lithologic trends. Colorogic changes.

1

a

CORED INTERVAL 29•2-^33•6m


Cyclic alternation of SILICEOUS-BEARING CALCAREOUS OOZE,dominantly grayish green (5G 5/2) in color with SILICEOUS-BEAR-ING MARL, dαminantly greenish black (5G 3/1) to black (5G 2/1) incolor. Burrowing and mottling are common. Zoophycus is 3t 64 cm inSection 1. Carbonate nodules, formed around burrows, are at 32 cm inSection 1 and 70 cm in Section 2. Burrows and mottles are subduedat the bottom of the core. .

5G 5/2,5GY 5/2,5G 4/ 2

Volcanic glass (dk)Carbonate unspec.

RadiolariansSponge spiculei

26/A 50/A1/T 2/R 30/A 15/C5/C 3/R10/C 5/C4/R 7/C4/R 15/C


5G2/ 1,5G3/ 1,5Y 3/ 2.5G 3/ 2,5GY2/ 1,5Y 4/ 2,5G6/ 1

5G5/ 2

VOID

SITE

TIM

E

RO

CK

UN

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bU3

BIO

STR

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GR

AP

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FOSSCHARAC

j

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LTER

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B

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33.6

0,

SEC

TIO

N

1

MET

ERS

9 CORED INTERVAL 3 3 . 6 3 8 . 0 m

GRAPHICLITHOLOGY Z

i δ

oooo

oo /

If LITHOLOGIC DESCRIPTION

VOID r, ., • c u | j n ^Dr i l l ing breccia o t rust , b roken nodules, and sed iment .

CARBON CARBON ATE: 9, CC% Carbonate 35% Organic carbon 0.3

t J SITE 5 0 3I o(—! I

RO

CIN

ITU

151

i

late P

li

4TIG

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IOST

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FOSSCHARAC

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TER

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l

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5 G ? / 1 Cycles of SILICEOUS-BEARING MARL, ranging from greenish black(5GY 2/1) and dark greenish gray (5GY 4/1) to light greenish gray

— (5G 8/1) in color. Gradations in color between the end types are

5G 6/1 ' burrow is at 84 cm iand open burrows are at 117 and 138 cm in Section1 and 30-38 cm in Section 2. Carbonate nodules, light gray (2.5Y

~ 7/2) in color, which are formed around burrows, are at 79 cm inSection 1 and 23 cm in Section 3. Pyritized burrows and zones enriched

5G7/1 ,5G8/1

SMEAR SLIDE SUMMARY1-30 1100 3-80

_ M D DPyrite 1/T - 2/T

5G 6/1 Clay minerals 81/D 28/A 29/AVolcanic glass (It) - 15/C -Volcanic glass (dk) - 2/R 1/T

~ 5 G 8 / 1 Carbonate unspec. 15/C 15/C 30/A5GY8/1 Foraminifers - 1/T -

Calcareous nannofossils 3/R 25/A 5/CDiatoms - 7/C 10/C

~ 5G 6/1 Radiolarians 1/T 7/C 12/CSponge spicules — — 1/T

~ N5 N3 Micrite - - 10/C2.5Y 6/2,5GY7/2

CARBON-CARBONATE: 10, CC— % Carbonate 46

% Organic carbon 0.4

5G 8 /1 ,5G6/1

-

5G5/1 ,5G4/1

5G2/1 ,5GY4/1 ,5Y 4/1

-5G 7/1,5G6/1

SITE 503 HOLE B CORE (HPC) 11 CORED INTERVAL 42.4-38.0 r

Note: Graphic üthotogy represents averasmear slides and does not reflect the dettypes. Gradational changes between smeinot imply actual Hthologic trends. Color

trary and doximate litho


Cycles of SILICEOUS MARL, ranging fron4/1) to light greenish gray (5G 7/1) in cole

Open burrows are found at 90-95 cm in Seition 3. A zoophycus burrow is at 134 cm inrows are at 85-90 cm in Section 2. The irSection 2 shows common bedding.

SMEAR SLIDE SUMMARY

5Y 5/1,5GY 6/1,5GY 5/1

5Y5/1,5Y 4/1.5GY2/1,5GY 5/2

daG

1 πon;ec

rk gradalOttl2 a

tional fr

reenish grayition in coloing are comind 35 cm in3. Pyritized

om 50 70 c

(5Gr be Tion.Secbun

Volcanic glass (dk)Carbonate unspec.

1/T29/ A 26/ A1/T 1/T25/ A 25/ A

• fossils 10/C 15/C10/C 10/C15/C 12/C10/C 10/C


SITE

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GRAPHICLITHOLOGY

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Cyclic alternation of SILICEOUS MARL, de minantly dark grayishgreen (5G 4/2) in color, and SILICEOUS BEARING MARL, which isdominantly greenish gray (5G 6/1), insediment composition are common. Bucommon. An open burrow is at 54 cm informed around burrows, are at 80 90zoophycus burrow is at 105 111 cm inrichment are common.

SMEAR SLIDE SUMMARY1 72 1 109M M

Pyrite 2/R 2/RClay minerals 25/A 16/CVolcanic glass (dk) 2/R 2/RCarbonate unspec. 20/C 25/AForaminifers 5/CCalcareous nannofossils 10/C 15/CDiatoms 15/C 5/CRadiolarians 15/C 15/CSponge spicules 1/TFish debrisMicrite 10/C 15/C

CLAY MINERALOGY <<2 m): 2 71 cSmectite 95%Chlorite &

Kaolinite 5%


_ 5GY8/ 1.N4,5G7/ 1.N55Y4/ 2.5G4/ 15GY6/ 1.5G5/ 1,5GY5/ 1.5G2

VOID

5Y 4/ 1,5Y3/ 1

1

color. Gradations in color androwing and color mottling areSectioand 1Sectio

1 145D_30/A1/T30/A2/R5/C12/C10/C _10/C

TI

n 2. Carbonate nodules.36 cm in Section 2. Ai 2. Areas of pyrite en

2 55D1/T25/ A1/T25/A1/T10/C13/C12/C1/T1/T10/C

SITE 503 HOLE B CORE (HPC> 13 CORED I N T E R VAL 5 1 . 2 5 5 . 6 m

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5GY6/ 1,5Y8/ 1.N4

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5GY 6/1


Cycles of SILICEOUS MARL, v5G 8/ 1, and 5G 7/ 1), cin color. Gradations intling are common. Carformed around burrowSpots, burrows, and z

live graycolor areaoπate nc

»hicb s light greenish gray (5GY 8/ 1,5Y 4/ 2), and dark olive gray (5Y 3/2)Commdules.

. are at 2 13, 8Dnes shov

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesFish debrisMicrite

1 140D_20/C1/T25/ A5/C10/C12/C12/C3/R2/R10/C

ving p

2 70D2/R38/A—15/C 5/C15/C15/C

10/C


,N4

, N4

5G 7/ 1,6/ 1.8/ 1 ,"Nβ

460.3

on. Burrowing and color mott light gray (2.5Y 7/2) in color.1 85, and 93 cm in Section 1./ rite enrichment are common.

3 50D1/T28/ A—26/ A 10/C13/C12/C1/T

10/C

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I Cycles of SILICEOUS MARL, ranging from tight greenish gray (5G» 8/ 1, 5G 7/1) to brownish gray (5Y 4/1} and dark greenish gray in color.* Fairly uniform with only subtle burrows and mottles from 70 150

cm in Section 1, 50 150 cm in Section 2, and 0 40 cm in Section5G 7/1 3. Other intervals are highly burrowed and mott led. Fragments of a

carbonate nodule are at 23 cm in Section 3. Pyrite enriched spots andburrows are common.

SMEAR SLIDE SUMMARY 1 80 2 60

5Y5/ 1.5B6/ 1 D DPyrite 2/RClay minerals 21/C 16/C

5 B 7 / 1 • N 6 Volcanic glass (dk) 2/R 1/TCarbonate unspec. 25/A 35/AForaminifers 5/C

5 G Y 6 / Calcareous nannofossils 10/C 10/CN β N 2 Diatoms 10/C 12/C

Radiolarians 15/C 12/C5Y 7/ 1, 5G 7/ 1, Sponge spicules 2/R

— 5Y8/ 1 Fish debris 1/Tr r v , , , Silicoflagellates 1/T5Y4/ 2 M i c r i t e 1 0 / c 1 0 / c

5 G7 / 1 > 25GY 6/ 1,4/ 1, CARBON CARBONATE: 14 CC

N 6 % Carbonate 43— % Organic carbon 0.3

5GY5/ 1.N5

5G 7/ 1. 5G 8/ 1,5G6/ 1

5B6/ 15B7/ 1

5GY6/ 1,5Y7/ 1.5G7/ 1

N5

Note: Graphic lithology represents averasmear slides and does not reflect the detypes. Gradational changes between smenot imply actual lithologic trends. Colorlogic changes.

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I Cycles of SILICEOUS MARL, ranging from light greenish gray (5G° 7/1) to dark green (5G 4/3) in color. Subtle burrowing and mott ling— dominate. Open burrows are at 100 cm in Section 1 and 9 cm in Sec

5GY 4/ 1 , t ion 2. Pyritized burrows and bands of pyrite enrichment are common.5B 5/1 A zoophycus burrow is at 12 cm in Section 3. Carbonate nodules are

at 6, 28, and 36 cm in Section 1; 132 cm in Section 2; and 108 cm5G 6/ 1, '" S e c t l o n "• A m i c m f a u l t l s a t 40 50 cm in Section 2.5G7/ 1

SMEAR SLIDE SUMMARY1 130 3 10D D

Clay minerals 31/ A 29/ A— Volcanic glass (dk) 2/R 1/T

5B6/ 1 N4 Carbonate unspec. 25/ A 20/CForaminifers 2/R

— Calcareous nannofossils 10/C 10/C5GY6/ 1, . .5G6/ 1 Diatoms B/C 10/C5Y7/ 2 'N2 Radiolarians 12/C 13/C

~ ^ ' Silicoflagellates 2/R5G4/ 3, Micrite 10/C 15/C5GY 5/ 2, N2

CLAY MINERALOGY ( < 2 m i : 2 71 cmSmectite 94%

— Chlorite &N3, N5. Kaolinite 6%5GY 6/1

' CARBON CARBONATE: 15, CC5G 7/ 1,6/ 1 % Carbonate 35

% Organic carbon 0.35G 6/ 2, 5/2

_ 5G 7/ 1, 6/1

^ 5 G 7/ 1, 6/1

5G 6/ 2, 5/2

N5

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GRAPHICLITHOLOGY

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— 5GY 8/1

5Y 4/3,5Y 5/3,N2

_5Y 4/2, 3/2,N2

5G 4/ 1, 5/ 1,N2

5B6/ 1.N5,N6, N2

5G7/1

5G5/2

5Y7/ 1


Cyclic alternation of4/1) and dark greenisING MARL, which i(5G 7/1) in color. Gcommon. Burrowing

Section 1. Carbonatein Section 1 and 117common. Faint whiteSection 3.

SILICEOUS MARL, which is grayish olive (5Yi gray (5G 4/1) in color, and SILICEOUS BEAR

yellowish gray (5Y 7/1) and light greenish grayadations in color and sediment composition areand mottling are common from 140 cm in Sec

Section 2. A zoophycus burrow is at 132 cm in

cm in Section 2. Burrows enriched in pyrite arelaminae at 0.5 1 cm spacing at 90 105 cm in

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.Calcareous nanπofossiDiatomsRadiolariansSponge spiculesSilicoflagellatesMicrite

2 50 3 60D D1/T 20/C 24/C2/R 1/T20/C 25/A

s 10/C 10/C18/C 14/C12/C 8/C

1/T2/R 2/R15/C 15/C


5GY7/1.6B7/1~ 5G 7/1

5GY 7/1

N6,5B7/ 1

5Y 7/ 1,

550.3

SITE 503 HOLE B CORE (HPC) 1 7 CORED INTERVAL 6β.8 73.2r

ite: Graphic lithology represents average composition derived from

MS. Gradational changes between smear slides are arbitrary and dot imply actual lithologic trends. Color variations approximate litho

3 | l | yl


5G 5/ 2,5GY 5/2,5GY4/ 1,5GY5/ 1,

Cycles of SILICEOUS MARLgray (5G 8/1) to dark greenish (

SMEAR SLIDE SUMMARY

5GY6/ 1,5GY5/ 1,N4

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.Calcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellatesMicrite

1/T28/A1/T25/A15/C10/C12/C1/T2/R15/C

—21/C1/T25/A10/C15/C10/C1/T2/R15/C


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~ Cycles of SILICEOUS MARL ranging f rom light greenish gray (5GY6GY 6/1 8/1 and 5G 8/1) and yellowish gray (5Y 8/1) to grayish olive (5Y 4/ 2)

and dark grayish green (5G 4/2) in color. Burrowing and mott ling arecommon. Zoophycus burrows are at 26 cm in Section 1 and 34 cm inSection 2. Burrows enriched in pyrite are common. Mott ling is subtle

5GY 4 / 1 , 5 / 1 , in the lower two sections.5G4/ 1 .N3

SMEAR SLIDE SUM M ARY 1 90 3 80 3 130

5Y4/ 2, D D D5G4/ 2 Pyrite 1/T 1/T

Clay minerals 35/ A 33/ A 30/ A

5B 7/ 1, 5 / 1 , Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolarians

5GY 5/1 Sponge spiculesSilicoflagellatesMicrite

0/C 20/C 10/Cn s/e0/C 10/C 10/C2/C 8/C 10/C4/C 10/C 15/C

1/T It 1/T 1/T5/C 15/C 15/C

CLAY M INERALOGY ( < 2 m) : 2 71 cmSmectite 91 %

5G 7/1 Illite 2%Chlorite &

Kaolinite 7%

~ CARBON CARBONATE: 18, CC5GY6/ 1, % Carbonate 565G 6/1 * Organic carbon 0.2

5GY7/ 1.6/ 1

5G 6/ 2,5GY4/ 1,N2

5GY 6/ 2, 6GY 5/2—

5GY 6/2

5G 6/ 1, 5/1

5Y8/ 1.5GYS/ 1.5G8/ 1

5G6 / 1 ,5GY4/ 1.N4

SITE 5 0 3 HOLE B CORE (HPC) 1 9 CORED INTERVAL 7 7 . 6 8 2 . 0 1


Cyclic alternation of CALCAREOUS SILICEOUS OOZE, which isdark greenish gray (5GY 4/ 1 and 5G 4/ 1) in color, and SILICEOUSMARL light greenish gray (5G 7/1) and greenish gray (5G 6/ 1 , 5GY 6/1)

upper half of Section 2 and less frequent elsewhere. Carbonate nodulesare at 12 and 44 cm in Section 1; 126 cm in Section 2; and 1 1 5 1 2 0

5Y4/ 1,5G 2/ 1, 7/1

5G 6/ 1, 7/ 1,5GY 6/1

6Y 5/ 1, 6/ 1,BGY5/15GY4/ 1,5G4/1

5Y 4 / 1 ,

5GY 5/1

5G 5/ 2,5GY 6/2


Clay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossDiatomsRadiolariansSponge spiculesSilicoflagellatesMicrite

1 140D38/ A2/R15/C2/R

ils 10/ C12/ C12/ C2/R1/T10/C


310.2

2 40D31/ A2/R10/C 5/C20/ C20/ C2/R 10/C

Note: Graphic lithology represents averasmear slides and does not reflect the de types. Gradational changes between smenot imply actual lithologic trends. Colorlogic changes.

erived from

SITE 503 HOLE B CORE (HPC) 20 CORED INTERVAL 82.0 86.4 m

Note: Graphic lithology represents average composition derived from

types. Gradational changes between smear slides are arbitrary and donot imply actual lithologic trends. Color variations approximate litho logic changes.


5G8/ 1 ,5B7 / 1 ,5GY8/ 1

of cyclic alternation of SILICEOUS MARL, dark greenish gray (5GY4/1) and greenish black (5G 2/1) in color, with SILICEOUS BEARINGMARL, light greenish gray (5GY 8/1 and 5G 8/1) and light bluish gray

cm in Section 3. The remainder of the undisturbed port ion of the

5G 7/ 1,5G2/ 1 ,5G5/ 1

5GY4/ 1,5G2/ 1


PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossiDiatomsRadiolariansSponge spiculesSilicoflagellatesMicrite

260D 30/ A1/T10/C

Is 5/C20/C15/C1/T3/R15/C

3 110D1/T26/ A 10/C3/R20/C10/C8/C 2/R20/C

CLAY M INERALOGY (< 2 m) : 2 711

5G4/ 1,5GY 4/1 CARBON CARBONATE:

% Carbonate% Organic carbon

20. CC72

0.1

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5 ( 3 7 / 1 Cyclic alternation of SILICEOUS BEARING MARL, which is lightgreenish gray (5GY 8/1 and 5G 8/1) in color and SILICEOUS MARL,

~ which is yellowish gray (5GY 5/1) and greenish gray (5G 6/1) in color.5G 6/1 Gradations between the endtypes in color and composition are com

mon. Zoophycus burrows are at 56, 67, and 115 cm in Section 3.5G 7/1 Pyrite enrichment of burrows is common.

5 G 6 / t SMEAR SLIDE SUM M ARY5G7/ 1 ' 2 120 3 115

— D DPyrite 1/T 1/T

_ 5G 7/1 C | a y minerals 23/C 39/ AVolcanic glass (dk) 2/R 1/T

5 G 6 / 1 Carbonate unspec. 15/C 15/C

5G 7/1 Calcareous nannofossils 15/C 5/C~ Diatoms 10/C 15/C

Radiolarians 10/C 12/C5G 6/ 2, _ . o / r ,5GY6/ 1 Sponge spicules 2/R

Fish debris 1/T_ Silicoflagellates 2/R 1/T

Micrite 15/C 10/C5GY 7/ 2,5G 7/2 CARBON CARBONATE: 21, CC


_

5GY8/ 1,5G8/ 1

—5GY 7/ 2, 5G 7/2

_ 5G 6/1

5GY7/ 1.6/ 1

5GY8/ 1,5B7/ 1

5G6/ 1 .5G7/ 1 ,__ 5G 8/1

5G8/ 1

5GY5/ 1,5G6/ 1

5G7/ 1

5GY6/ 1,5Y6/ 1

ooSITE 503 HOLE B CORE (HPC) 22 CORED INTERVAL 90.8 95.2 m

III

fi

Note: Graphic lithology represents average composit ion derived f romsmear slides and does not reflect the detailed alternation of sedimenttypes. Gradational changes between smear slides are arbitrary and donot imply actual lithologic trends. Color variations approximate litho logic changes.


Cyclic alternation of SILICEOUS M ARL, which is olive black (5Y2/1) and very dark greenish gray (5GY 3/11 in color, and SILICEOUS BEARING M ARL, which is light greenish gray (5G 7/1) in color.Gradations between endtypes in color and composition are common.

tiling ; below 70 c

—5G8/ 1,

_ 5G7/ 1

5G7/ 1—

5G4/ 1,5G7/ 1,

_ 5G 6/15G4/ 1,5G7/ 1

5G 5/3,5GY5/ 1,5Y4/ 1

A zoophycusvery uniformdisturbed secpresent in the

burrbelowion asedirr

3W is20

t theent.

at 5 15 cmm in Setop of t


PyriteClay mineralsVolcanic glassVolcanic glassCarbonate un

Calcareous naDiatomsRadiolarians

( It ) .(dk)pec.

nnofossils

1 60D1/T34/A

20/C

10/C8/C12/C

ctionhe co

2 25D_34/A

15/C

10/C10/C15/C

in Section 2. The sed3. Carbonate nodules ae. Some pyrite enrichπ

3 6D2/R30/A5/C1/T10/C2/R10/C15/C15/C

CLAY M INERALOGY ( < 2 rn) : 2 71 <Smectite 9 1 %


5G7/ 1,5GY7/ 1,5G6/ 1

SITE 503 HOLE B CORE (HPC) 23 CORED INTERVAL 95.2 99.6 m

MSIISLITHOLOGIC DESCRIPTION

CARBON CARBONATE: 23, CCDrilling % Carbonate 43breccia % Organic carbon 0.2

SITE 503 HOLE B CORE (HPC) 24 CORED INTERVAL 99.6 104.0 r


Cycles of SI LICEOUS CALCAREOUS MARL, rangiish gray (5G 8/1) to medium gray (N5), olive grayish gray (5G 5/1) in color. Gradations between etcommon. Below 120 cm in Section 1, burrowin

core shows a collapse structure which appears t>

ng from light grf(5Y5/ 1)andgriidtypes in color

5GY6/ 1,5G6/ 1,5Y6/ 1

5G7/ 1,5GY7/ 1,5Y8/ 1

Clay mineralsVolcanic glass (dk)Carbonate unspec.ForaminifersCalcareous nannofossilsDiatomsRadiolariansSponge spiculesSilicoflagellate!Micrite

18/C 15/C4/FI20/C15/C10/C1/T2/R15/C

32/A1/T20/C

6/C15/C15/C2/R—10/C

CARBON CARBONATE: 24, CC

5G5/ 1,5Y5/ 1,5GY 6/3,5G 5/2,

5GY8/ 1.5Y8/ 1

SITE 503 HOLE B CORE (HPC) 25 CORED INTERVAL 104.0 108.4 r

Note: Graphic lithology represents aversmear slides and does not reflect the ditypes. Gradational changes between smnot imply actual lithologic trends. Colologic changes.


Cycles of SILICEOUS MARL, ranging in color from light greenishgray (5GY 8/ 1, 5G 8/1) and pale yellow (5Y 5/1) to greenish gray(5GY 6/1). Burrowing and mottling are common throughout. Azoophycus burrow is at 143 148 cm in Section I.

5GY7/ 1.N8.5Y7/ 1,5G7/ 1

VOID

5GY6/ 1,5G 5/2,5G8/ 1,5GY7/ 1,N4

5GY8/ 1,5Y8/ 1,5Y 8/3,

SMEAR SLIDE SUMMARY

PyriteClay mineralsVolcanic glass (dk)Carbonate unspec.Calcareous nannofossilDiatomsRadiolariansMicrite

2 20D2/R21/ C2/R15/C

s 10/ C20/ C15/C15/C


500.3

2 121D1/T23/ C1/T10/C30/ A15/C10/C10/C

SITE

IME

R

OC

UN

IT

>

s

Hi

5 0 3o

1

JTR

ATIG

R/

ZON

E

O

|g

_

6

_

S

HOLE B

FOSSILCHARACTEF

z

°

5E2

116

I<

FP

2

%

z

z

CM

z

o

CM

1s

CG

CORE (HPC)

| _

oCO "o

109

1111

.14

110.

98

SEC

TIO

N

1

2

CC

MET

ERS

_

_

1.0 —

_


GRAPHICLITHOLOGY

VOID~—!H ~ ~_"

,1,1

__ _•‰ r~ ^

~

—

ir:

~

'jr.'jr.

'TJ

rl r"_z

E ili

i

—

• \—

"CΛ

j

y_

_ .^ v• " "—\J

=

\_ _^—\_/~^)—O —

=o= _rv_

j — , * •

j _ _Lj _ _L. 1 .

J_"J~_Li

J _ _LJ _ , _L_L_—* _£j J ,

_ 1 _ * | 1

J 1 1 i 1

1

L.

—l± i " _!_ •α ~ _l _" '

IW

° mJ t 3 Q

ooΛoQoooo

ó

DSC

UJ

*

*

:


Cycles of SILICEOUS NANNO MARL, ranging from light greenishray (5G 8/1 and 5GY 8/1) to greenish gray (5GY 6/1) and green (5GY

5/3) in color. The upper section is highly disturbed. The sediment islighly burrowed and mottled. Pyrite enrichment is abundant fromt5 -H5cm in Section 2.

SMEAR SLIDE SUMMARY

5G7/1.2-40 2-70D D

N5 pyrite 1/T 1/T;iay minerals 17/C, 23/C/olcanic glass (dk) - 1/TCarbonate unspec. 10/C 10/Coraminifers 5/C

,alcareous nannofossils 25/A 20/CDiatoms 20/C 15/C

5GY6/1 R<>diolarians 10/C 10/C5G 7/3. ' licoflagellates 2/R -

_ 5G8/1 Micrite 10/C 20/C. 5G8/1.

IJ jXS^• CLAY MINERALOGY (<2µm): 2-71 cm_ 6 G Y " 1 . N ' ! smectite 91%

5GY6/1, ite 5%5GY 6/3, Chlorite &5Y6/3 Kaolinite 4%

5GY7/1, CARBON-CARBONATE: 26, CC5Y7/1,5G7/1,

- N2

5B7/1,58 8/1.5Y8/1

N8

t Carbonate 72*> Organic carbon 0.1

ts)

SITE 503

r—O cm Hole 503

- 2 5

- 5 0

- 7 5

—100

—125

»—150 1-1 1-2 1-3 1,CC

220

SITE 503

r—Ocm Hole 503A

- 2 5

- 5 0

•

- 7 5

—100

- 1 2 5

L-150

I

1-1 1-2 1,CC 2-1 2-2 2-3

er.LU>OüLUCT

o

‰^.^^mt

4-1 4-3 4-4

221

SITE 503

Hole 503A

5-2 5-3 5, CC 7-1 7-2 7-3 7,CC 8 9-1 9-2

SITE 503

r—0 cm, Hole 503A

h-25

h-50

Moo

I—125

1—150 9-3 9, CC 10-1 10-2 10-3 10, CC 11-1 11-2 11-3 11, CC 12-1 12-2

223

SITE 503

ρ 0 cm Hole 503A

h 25

•

h 50

h 75

Moo

h 125

• 150 12 3 12, CC 13 1 13 2 13 3 13, CC 14 1 14 2 14 3 14, CC 15 1 15 2

224

SITE 503

r—0 cm Hole 503A

- 2 5

- 5 0

—75

—100

—125

1—150 15-3 15, CC 16-1 16-3 16, CC 17-1 17-2 17, CC 18, CC 19-1

SITE 503

r—0 cm Hole 503A

2 5

5 0

7 5

•100

—125

• 150 19 3 19, CC 20 1 20 2 20 3 20, CC 21 1 21 2 21 3 21 , CC 23 1 23 2

226

SITE 503

0 cm Hole 5 0 3 ^ ^ ^ ^ β ^ ^ ^ β _ _ . , ^ H J M H • •

V HI βf jB *H» r* ^Q j MKTTMI K2

\

li • I ;;\WβmBBà H^B^ * ^ B

WE.'- -'" at •*• - I J- :." I > > ! * * * !

^ El -I *• I

f * 1 * 1 Ê•^^*'^

— 1 5 0 23, CC 24-1 24-2 24-3 24, CC 25 27-1 27, CC 28 29-1 29-2 29-326

227

SITE 503

r-0cm

—25

— 50

Hole 503A

- 7 5

—100

—125

,..

150 29, CC 30-1

228

.

30-2 30, CC 31-1 31-2 31-3 31, CC 32-1 32, CC

i4

-

33, CC

SITE 503

r—0 cm Hole 503A

34-1 34-2 34-3 34, CC 35-1 35, CC 36-1 36-2 36-3 36, CC 37-1 37-21—150

SITE 503

r—0 cm Hole 503A

- 2 5

— 50

- 7 5

—100

—125

1—150 37, CC 38, CC 39-1 39-2 39-3 39, CC 40-1 40, CC 41-1 41-2 41-3 41, CC

230

SITE 503

p—O cm Hole 503A

2 5

— 50

7 5

—100

—125

• 150 43 3 43, CC 44 1 44 2 44 3 44, CC42 1 42 2 42 3 42, CC 43 1 43 2

SITE 503

Hole 503A

LU f ‰ ' ^5 k i ; i P. b \ • '• ! ;.

o 1

—1 0 0 !" . V J

S α ^ 4 ' • "" '– *' • "" «. . i j H h ' * — ' i ••

. < ' ; ' v. ! " ' , • * 6 * !

—125 f

U » Λ • *«. , Λ

• • • • • i ' I I I • H • I I I 'I O U 45 46 1 46 2 47 1 47, CC 48 1 48 2 48 3 48, CC 49 1 49 2 49, CC

46, CC232

SITE 503

r—0 cm Hole 503A

- 2 5

— 50

- 7 5

—100

—125

•—150 50-1 50-2 50-3 50, CC 51-1 51-2 51-3 51, CC 52-1 52-2 52-3 52, CC

233

SITE 503

r—"0 cm Hole 503A

- 2 5

- 5 0

- 7 5

—100

—125

1—150 53-1 53-2 53-3 53, CC 54-1 54-2 54-3 54, CC

234

SITE 503

r-0cm, Hole 503B

- 2 5

- 5 0

- 7 5

—100

—125

1—150

*._ <'f

1-1 1-2 1,CC 2-1 2-2 2, CC 3-1 3-2 3-3 3, CC 4-1 4-2

235

SITE 503

r - 0 cm Hole 503B

- 2 5

- 5 0

- 7 5

1—1504-3 4, CC 5-1 5-2 5-3 5, CC 6-1 6-2 6-3 6, CC 7-1

236

SITE 503

r -0 cm Hole 503B

- 2 5

- 5 0

—75

—100

—125

1—150 7-3 7,CC 8-1 10-3 10, CC 11-18-2 8-3 8,CC 9-1

SITE 503

~ n ™ Hole 503

- 5 0

.

—75

f •

—100

1—150

238

11-2 11-3 11, CC 12-1 12-2 12-3 12, CC 13-1 13-2 13-3 13, CC 14-1

SITE 503

r -0 cm Hole 503B

—125

1—150

•.i-•

14-2 14-3 14, CC 15-1 15-2 15-3 15, CC 16-1 16-2 16-3 16, CC 17-1

239

SITE 503

p—0 cm Hole 503B

- 2 5

—50

—75

1—150 17-2 17-3 17, CC 18-1 18-2 18-3 18, CC 19-1 19-2 19-3 19, CC 20-1

240

SITE 503

r—0 cm Hole 503B

- 2 5

50

—75

—100

'125

L-150

• ••i

20-2 20-3 20, CC 21-1 21-2 21-3 21, CC 22-1 22-2 22-3 22, CC 23-1

241

SITE 503

r-OcmJ!^503,

- 2 5

- 5 0

- 7 5

1—150

242

23, CC 24-1 24-224, CC

25-1 25-2 25-3 26-1 26-225, CC 26, CC

Documents

Site 503: Eastern Equatorial Pacific