Using geophysical methods to characterize an abandoned uranium

Journal of Applied Geophysics 67 (2009) 14–33

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Journal of Applied Geophysics

j ourna l homepage: www.e lsev ie r.com/ locate / jappgeo

Using geophysical methods to characterize an abandoned uraniummining site, Portugal

E. Ramalho a, J. Carvalho a,⁎, S. Barbosa b, F.A. Monteiro Santos c

a Instituto Nacional de Engenharia, Tecnologia e Inovação, Apartado 7586, 2721-866 Amadora, Portugalb EDM, Rua Sampaio e Pina, 1-7.°, 1070-248 Lisboa, Portugalc Universidade de Lisboa, Centro de Geofísica da Universidade de Lisboa-IDL, Campo Grande, Ed. C8, 1749-016 Lisboa, Portugal

⁎ Corresponding author. Tel.: +351 214705521; fax: +3E-mail addresses: [email protected] (E. Ramalho

(J. Carvalho), [email protected] (S. Barbosa), fasantos@f

0926-9851/$ – see front matter © 2008 Elsevier B.V. Aldoi:10.1016/j.jappgeo.2008.08.010

a b s t r a c t
a r t i c l e i n f o
Article history:
A major plan for Portugal M Received 16 February 2007Accepted 15 August 2008
Keywords:Waste disposal siteGroundwater circulationEnvironmentElectromagnetic methodsElectrical methodsSeismic methods

ainland is being envisaged to use old open pits from abandoned uranium miningsites as “Waste Containment Deposits”. These areas will store mining waste from other adjacent mines. Theold mining sites classification to this kind of usage is carried out accordingly to its location, accessibility,geological and hydrogeological conditions. Mining waste deposition in the open pits may however causeenvironmental problems related with geological and hydrogeological features that must be predicted andprevented before a particular site is chosen. Therefore, the identification of faults and conductive zones thatmay promote groundwater circulation and the spread of contaminated waters is of great importance, sincethe surrounding area is highly populated. The possible negative environmental impacts of the presence ofsuch potential waste disposal sites are therefore being assessed using geophysical methods and geologicaloutcrop studies in several geological and hydrogeological critical areas. The abandoned Quinta do Bispouranium mine is one of such places. This old open pit, chosen as one of the sites to be used in the near futureas a “Waste Containment Deposit” (accordingly to the above mentioned criteria), needs to be characterized atdepth to prevent any possible negative environmental impacts. Thus, the acquisition, processing andinterpretation of electromagnetic, electrical and both seismic refraction and reflection have been carried out.2D schematic models have been constructed, showing alteration and faults zones at depth. These fault zonescontrol groundwater circulation and therefore, future water circulation problems with negative environ-mental impact may be predicted and prevented.

© 2008 Elsevier B.V. All rights reserved.

1. Introduction

Among the 61 old uranium abandoned mines in MainlandPortugal, three mining areas were selected for the construction of a“Waste Containment Deposit” (collecting site of mining waste fromother adjacent mines), according to “The Waste ManagementCriteria and Strategy” developed by EXMIN-Companhia de Indús-tria e Serviços Mineiros e Ambientais, S.A. (thereafter designatedEXMIN) (EXMIN, 2002–2003). These sites are located in CentralPortugal, where uranium was extensively mined during severaldecades in the 20th century. Since 2003, different types of sitecharacterization studies, comprising detailed geology and hydro-geology studies are being conducted by Empresa de Desenvolvi-mento Mineiro, SGPS, S.A. (thereafter designated EDM), the formerEXMIN.

EDM S.G.P.S is a holding company that represents the PortugueseState interests in the Mining Sector. EXMIN is a Group-Company of

51 214719018.), [email protected] (F.A. Monteiro Santos).

l rights reserved.

EDM and a Concessionaire of the Portuguese State for “EnvironmentalRemediation of Abandoned Mines”. This Concession was establishedbetween both Environmental and Economy Portuguese Ministries.Since the year 2000, EXMIN has developed environmental character-ization studies and remediation projects for the prioritary old mines,including the old Uranium mines like Quinta do Bispo. These studiesaim at establishing the geo-environmental feasibility of each site.Since a “Waste Containment Deposit” is defined as a collection site ofmining waste from other adjacent mines, it must be carefully chosenaccording to its geological characteristics and environmental risks. Fora successful achievement of these purposes, a good understanding ofthe groundwater drainage system is required.

The Quinta do Bispo abandoned mine stands as one of the threemining areas selected for the construction of a “Waste ContainmentDeposit”. It has a centralized geographic location (Fig. 1), in the Viseudistrict, near one of main roads that serve Central Portugal. On theother hand, it also has some negative points, due to its location in thesuburbs of Mangualde town, an areawith high population density thatis also abundantly industrialized. Considering these features, specialcare must be taken in the site evaluation. In this case, geological andhydrogeological studies covering a considerable period of time lead to

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Fig. 1. Location and geological map of the old Quinta do Bispo Mine and several photos with views of the mine. Red lines indicate the locations where each photo was taken. (Forinterpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

15E. Ramalho et al. / Journal of Applied Geophysics 67 (2009) 14–33

some technical doubts, namely regarding the hydrogeological condi-tions in relation with local fracturing.

These characteristics are important to define, since a choice basedon insufficient information may lead to environmental problems,more and more difficult to solve, as the process reaches an advancedstage. Other types of information are therefore requested andgeophysical methods were considered as a possible solution toovercome this situation. Therefore, geophysical surveys involvingseveral methods in the geological and hydrogeological critical areaswere conducted with the aim of characterizing the open pit limits and

confirm mapped faults and fractures, which may increase the risk ofinteractions between the waste deposit and ground environment.

The Quinta do Bispo ore was discovered in 1957. The open pitexploitation began in 1979 and ended in 1987; the mine annexes andthe dump occupy a total area of about 158,000 m2 (EXMIN, 2000–2001). The open pit has reached a depth of 75 m below ground leveland more than 460,000 tons of ore was produced during that time,with an average concentration of about 910 ppm (EXMIN, 2000–2001). From 1987 to 1992, waters in the open pit were monitored, anddue to the large amount of uranium, an ionic permute unit was

Table 1Average piezometry, water conductivity and water temperature at the time of the yearthe geophysical survey was acquired (May)

Piezometer Depth(m)

Average piezometry in May(m)

Water conductivity(μS/cm)

Temperature(°C)

F4 92 9.3 145 15.1F8 30 1.8 3120 15.7F11 37 1.8 571 16.5F12 66 1.5 1600 15.2F17-A 42 9.0 688 14.8

Measurements were carried out in the boreholes located nearby the selected lines.

16 E. Ramalho et al. / Journal of Applied Geophysics 67 (2009) 14–33

installed. From 1992, “poor” ore from dumps were re-processed withconcentrations between 300 and 500 ppm and deposited in the openpit for an in situ leaching process (EXMIN, 2000–2001). In the Quinta

Fig. 2. Geological map of the old Quinta do Bispo Mine, with location of the four profilessoundings (green) and location of the drilled boreholes (F#). Numbers in the four lines cointerpretation of the references to colour in this figure legend, the reader is referred to the

Fig. 3. Line 1: Conductivity section of the inverse EM34 model s

do Bispo mining site, the open pit has dimensions of about 300×90×80 m, which corresponds to an excavation volume of about2,000,000 m3 (photos 1a and 1f, from Fig. 1). There is a “poor” oredump with about 100,000 tons and a sterile dump partially reforestedwith about 1,500,000 tons.

2. Geological and hydrogeological framework

According to EXMIN (2000–2001), the main geological unit thatoutcrops in the region (Fig. 1) is the medium to coarse grained, twomicas granite, sometimes kaolinitised with many ferruginous impreg-nations and/or haematization. Meta-sediments of the Schist Grey-wake Complex also crop out on several places, with strong contactmetamorphism, sometimes with the occurrence of migmatites. Theore is located in a contact of granite with embedded meta-sediments,

where geophysical surveys were acquired using different methods, vertical electricalrrespond to EM locations, used for common referential of all geophysical surveys. (Forweb version of this article.)

howing F12 borehole and VES P1 locations. Units in mS/m.


composed by brownish, ferruginous, clayey-mica altered schists. Themain fault system strikes N48°W, with clayey filling. A N–S fracturingsystem has also expression in the area (EXMIN, 2000–2001).

Mineralization is composed by autunite and torbernite, and blackuranium minerals are spread in the contact zone, either in the meta-sediments or in the granites. In the meta-sediments, disseminatedsulphides occur.

Regional groundwater flow is towards the SE and the shallowaquifer is contaminated in the vicinities of the old mine withinfiltrated water with acidic leachates from the dumps and residualwater treatment muds, due to possible outflows from the decantationbasins, mainly in the rainy season. Table 1 shows the averagepiezometry, water conductivity and water temperature at the timeof the year the geophysical surveys were conducted (May). Theseparameters were measured in the boreholes located nearby theselected lines (see Figs. 1 and 2 for location).

As it can be seen from Table 1, borehole water conductivity rangesfrom 14.5mS/m in F4 to 160mS/m in F12 and 312mS/m in F8, which isconsiderably high. The soil contamination potential with heavymetalsand radioactive elements from the dumps is high. The acidiccharacteristics of the embedded ore rock and the ore leached insidethe open pit have contributed to the high conductivities of the surfacewater, with pH ranging from 3 to 3.5 and water conductivity rangingfrom 400 to 600 mS/m, with rock permeability varying between1.2×10−7 and 9×10−8 m/s (EXMIN, 2000–2001). Surface water hasbeen the object of a neutralization process and chemical precipitationof radionuclides (226Ra) (EXMIN, 2000–2001).

3. Data acquisition and processing

Four profileswere carried outwith the aimof understanding the in-depth behaviour of the mapped faults surrounding the old mine openpit (Fig. 2). In each profile, electromagnetics EM34, electrical, seismicreflection and refraction surveyswere carried out. Their locationswerechosen according to the positioning of the geological features toinvestigate and topographic constraints (Fig. 2). Data processing foreach method was similar for all profiles and had the objective ofconstructing schematic models highlighting the main alteration areas,fracturing zones and conductive groundwater flow paths. From theseresults, a better supported, technically based decision regarding thefuture use of the old open pit as a mining waste storage can be taken.

3.1. Electromagnetics EM34

An electromagnetic survey using Geonics EM34-3 equipment wascarried out over each profile. The utility of such system inhydrogeological and environmental studies is well-known (see e.g.,Stewart, 1990; Goldstein et al., 1990 and references therein).

The measurements were taken every 10 m using 10 m, 20 m and40m length cables (see Fig. 2), with frequencies of 6.4 kHz,1.6 kHz and0.4 kHz, respectively. However, some problems occurred during dataacquisition due to the electromagnetic cultural noise caused byindustries and the “Beira Alta” railroad. The high level of noise wasobserved mainly in the northern part of Line 2. Overload was alsodetected in different degrees in all survey lines, but both problemswere overcome according to the method suggested by McNeill (1980).

Data inversion was accomplished with software EM34-2D, using a1D laterally constrained method that has proved to be effectiveto delineate the main geological structures using Geonics EM34equipment (Santos, 2004). The inverse problem is solved using asmooth inversion algorithm, where each 1D conductivity model,obtained beneath each measurement site, is constrained by its

Fig. 4. a) Borehole F12 log. Lithological description: OV: overburden; GGQF: grey granitewith quartz fragments; AGG: altered grey granite; SGG: soft grey granite with quartzfragments; GYUA: Grey-yellowish unaltered granite. Alteration degree: 1 — Weaklyaltered; 2 — Low alteration; 3 — Altered; 4 — Highly altered. b) VES P1 inverse modellocated over Line 1. The dashed line represents the true resistivity versus depth model,with the uppermost layer omitted. The dotted lines are displayed to help visualization.Current electrode distance corresponds to AB/2 (m).


neighbours (Santos, 2004). The finalmodel is a rough representation of atwo-dimensional resistivity or conductivitymodel. TheRms errors of themodels presented in this work are lower than 20%, which can beconsidered satisfactory taking into account the quality of the data.

3.2. Vertical electrical soundings

Five vertical electrical soundings (VES) were also acquired usingthe Schlumberger array, in order to compare the results with thoseobtained from the EM34 survey and, where it is possible, integratethem. The maximum distance for current electrodes depended on thetopography and on the available space. The AB/2 distance varies from1 m till 125–200 m. The VES were carried out at well defined sites,coincident with EM34 measuring points and/or boreholes, andwithout the probable presence of faults. At each profile the VESswere oriented according to the profile direction.

In some cases, however, due to topography, accessibility andequipment operation abilities, the VESs did not reach the unalteredbedrock, which is reflected in data quality and final adjustment of themodel. Nevertheless, each VESs model ended with growing resistivityvalues. The data have been inverted assuming 1Dmodel and using theridge-regression method (Johansen, 1977). Rms values were rangingfrom 2 to 6%. Where available, borehole data was used to performinterpretation adjustments, namely confirming depths and refiningthe geological alteration intervals.

3.3. Seismic refraction and reflection

Seismic refraction datawas acquired along almost the full length ofthe lines, in order to provide information on the degree of alteration

Fig. 5. Top: Seismic refraction interpretation of Line 1, with location of borehole F12 indicatspread was used for Line 1. Letters represent the position of shotpoints used in the refractionEM11 to 17, with fault interpretation. Red lines correspond to interpreted faults. (For interpreversion of this article.)

from the velocity models. A layout of 24 or 48 (in profile 4), 50 Hzvertical geophones with a 2 m spacing was employed. Several spreadswere therefore used for each line. End-off shots were fired with 1 mand 20 m (where possible) offsets to the nearest receiver. To constrainthe uppermost layers, shots were fired inside the receivers spreadevery 10 m.

Reflection data was also acquired in confirmed or probable faultzones. Although the seismic reflection method is mostly adequate forsedimentary environments, some success has been obtained in crystal-line or hard rocks settings (e.g. Kim et al.,1994; Stanley and Pavlis,1999;Eaton et al., 2003). A shot spacing of 2mwas therefore used in the abovementioned areas inside the fixed receiver layout, with a source tonearest receiver offset of 1 m. In bothmethods, datawas acquired usingan accelerated weight-drop seismic source (Gisco AWD-550T) and a 24bit digital data acquisition system (Seistronix RAS-24). A 0.5 mssampling rate with a total recording length of 500 ms was used.

The refraction interpretation of the data was performed usingcommercial software based on the delay-times method and ray-tracing (Haeni et al., 1987). The delay-times method is used to obtain afirst 2.5D velocity model which is refined with a three step iterativeprocess of observed and calculated arrival time residuals minimiza-tion. Velocities are determined by a weighted (by receiver number)average of a simple linear regression of the time–distance curves andthe generalised reciprocal method (Palmer, 1980) where reciprocaltimes are available.

The reflection data was processed with the Seismic ProcessingSoftware-SPW™ using the following flow: trace editing, gains,frequency filtering, first arrival mute, deconvolution, frequencyfiltering and amplitude equalization, velocity analysis, NMO correc-tion and stack, automatic residual statics (surface consistent), DMO

ed. Average velocities of P-waves for each spread (receiver layout) are shown. A singleinterpretation. Bottom: Depth-converted stacked seismic reflection section from pointstation of the references to colour in this figure legend, the reader is referred to the web

Fig. 7. VES P2a and P2b inverse models of soundings located over Line 2. The dashed linerepresents the true resistivity versus depth model, with the uppermost layer omitted.The dotted lines are displayed to help visualization. Current electrode distancecorresponds to AB/2 (m).

Fig. 6. Line 2: Conductivity section of the inverse EM34 model. Units in mS/m. Location of the VES acquired over this profile are indicated.


integral correction (Yilmaz, 2001), FK migration with stretch (Stolt,1978) and post-stack filtering. Depth conversion of the profiles wasperformed using interval velocities calculated from stackingvelocities.

4. Results

The final interpretation was made using all available geophysical,geological and hydrogeological data. Whenever possible, borehole logdatawas used, so that geological information could be relatedwith thegeophysical data. Abnormal alteration zones were related with faults,dykes or the water table and conceptual models for each profile werecreated based on data from the geophysical surveys. A commonreferential is provided for all surveys, which can be seen in map viewin Fig. 2. A discussion regarding geophysical (electrical and seismic)and geological properties for the upper layers in each line will bepresented in this section. The structural interpretation of the lines,including the seismic reflection data analysis, will be discussed inSection 5. The lateral correlation of significant faults/structuresbetween the profiles is also realised in Section 5.

4.1. Line 1

The conductivity section of the inverse EM34 model, the boreholeF12 log, the VES P1 inverse model, the seismic refraction interpreta-tion and the stacked seismic reflection section from points 11 to 17 forLine 1 are represented in Figs. 3–5.

From the observation of the conductivity section (Fig. 3) of theEM34 inverse model, we note that Line 1 has two zones with differentcharacteristics. The homogeneous character registered betweenpoints 1 and 8 in the conductivity profile 1 (covered only withelectromagnetic method) shows that the shallow alteration zoneextends until about 12 m in depth. High conductivities are probablydue to the existence of a streamline in that area resulting from waterdischarge from decantation basins; as seen in Table 1, borehole F8(located SW of the profile, 30 m apart), with water conductivity of312 mS/m, seems to be consistent with this hypotheses. VES P1 showsthe alteration zone in the shallowest 40 m, which is in accordancewith the EM profile.

With the seismic refraction method, 4 horizons were interpreted.The 1st layer, with thickness varying from 6 m at the NE (wherealluvium deposits outcrop), to 2–3 m in its SW part, where veryaltered coarse grained granites outcrop, has a velocity of 670 m/s. Thesecond interpreted layer has a P-wave velocity of 1370 m/s, and itshould correspond to very to moderately altered granite. The base ofthis seismic horizon is located at a 7 m depth in SWand at an 11–12 mdepth in the NE part of the profile near point 18, going up again to the7 m at the NE end of the profile. Below this layer, there is a 3rd layerwith a velocity of 3350 m/s, corresponding to altered to slightly

Fig. 8. Top: Seismic refraction interpretation of Line 2. Average velocities of P-waves for each spread (receiver layout) are shown. Letters represent the position of shotpoints used inthe refraction interpretation. Bottom: Seismic reflection profile, with fault interpretation overlaid. Depth conversion was performed with stacking velocities.


weathered granite, with such strong thickness variations that theinterface with the 4th layer is extremely irregular, varying approxi-mately between 9 and 29 m. The velocity found for the 4th layer was4110 m/s. However, due to the strong dips found for this layer, thisapparent velocity is quite higher than the true velocity.

4.2. Line 2

The conductivity section of the inverse EM34 model is shown inFig. 6, the VES P2a and P2b inverse models in Fig. 7 and the seismicrefraction and reflection data interpretation in Fig. 8. In the refractionprofile (and the following refraction profiles) the P-wave velocities foreach spread are presented.

In this line, located topographically above the other lines and theold mining pit, the highest conductivities are registered in the zoneswhere the clayey-arkosic deposits outcrop, which present higher

Fig. 9. Conductivity section of the inverse EM34model of Line 3. Units in mS/m. Location of V

electrical conductivity than granites. The conductivity values, con-sidering the results of the EM profile, also highlight the existence indepth of a high conductivity zone between points 12 and 17. This highconductivity zone corresponds to the clayey-arkosic deposits, reach-ing depths that can be higher than 50–60 m. Model interfaces arerelatively smooth for a granitic zone.

With the seismic refraction method, four horizons were alsointerpreted in Line 2. The 1rst horizon, with an average (of all spreads)P-wave velocity of 520 m/s and 0–5 m thickness, is composed byclayey-arkosic deposits, except in its N part, where granite is theoutcropping rock. The following seismic horizon has an averagevelocity of 1200 m/s and it corresponds to very altered/fracturedgranite, until about a 13 m depth. This depth is consistent with theconductivity profile clearly marked by the water table and with theresistivity values obtained in VES P2b acquired over Line 2 (Fig. 6). Thelatter indicates the presence of a shallowhomogeneous horizontal layer,

ES acquired over this line is indicated. Projection of borehole F4 in the line is also shown.


reaching a depth of about 19 m. In VES P2a the thickness of the alteredlayer is affected by the fault zone located between points EM12 and 17,increasing to about40m.At anaveragedepthof about 13mthere is a 3rdseismic horizon with an average velocity of 2300 m/s, which can beassociated with altered/fractured granite. At a depth of 31–32 m is the4th seismic horizon,with P-wave velocities of 3910m/s. This value is stilllow when compared with the values encountered for unaltered coarsegrained granites; therefore, this horizon must correspond to low tomedium altered and fractured granite.

4.3. Line 3

Both EM and electrical prospecting results obtained in this linewere considered with some reserve due to its proximity to the BeiraAlta railway and therefore the Geonics EM34 40m cable was not used.The conductivity section of the inverse EM34 model is presented inFig. 9, while the VES P3 inverse model and the borehole F4 log for Line3 are represented in Fig. 10. The seismic refraction interpretation andthe seismic reflection stacked section from points EM1 to 8 are shownin Fig. 11.

Similarly, the results obtained from VES P3 and EM34 using the20mcablewere also consideredwith some caution, since disturbanceswere also registered, and due to this problem, before interpretation ofthemodelling, results were relatedwith borehole F4 log, by projectingit in point 7 of the EM profile, and with the seismic refraction result.Since a reasonable consistence among these results was found, thesame consistence was admitted to the rest of the profile.

Line 3 appears to be the onewith less altered coarse grained granite.With the seismic refraction profile 4 layers were also detected. Theshallowest three layers show a decreasing degree of alteration withdepth. Borehole F4, located a few meters south of point EM7, shows“soft grey granite” in the shallowest 6m,which corresponds to the firsttwo refraction layers, with average velocities of about 410 and 770m/s.The bottom of these two seismic layers is located at an 8mdepth at theborehole projection point in the profile. Below this depth, a third layerwith P-wave average velocity of about 2480 m/s was detected. The logof borehole F4 indicates the presence of yellow granite between 6 and21 m, followed by fine grained granite at greater depths.

The latter granite probably corresponds in the refraction profile to ahorizon at a depth of 25 m that has an average velocity of 5810 m/s,which means that its alteration degree is weak, in opposition of what isstated in the borehole F4 description. The clayeygranite between45 and54 m depth reported in the borehole F4 geological log description wasnot detected in the refractionprofile, since it shows a lower velocity thanthe upper layer (or was beyond the detection capability of the profilewith the acquisition parameters used). The corresponding reflectionprofile shows, as in the refraction interpretation, that the seismichorizons are mainly horizontal, though they present several irregula-rities and discontinuities some of which probably correspond to faults.

4.4. Line 4

This line appears to sample the most disturbed zone of the fourprofiles due to fracturing located at its W part, although in depth somefaults appear to exist in its E part. Fig. 12 presents the conductivitysection of the inverse EM34 model, Fig. 13 shows the VES P4 inversemodel while Fig. 14 depicts the seismic refraction interpretation, andthe reflection section from points EM12 to 20. Although water

Fig. 10. a) Borehole F4 log: Lithological description: SGG: soft grey granite; YG:yellowish granite; FGGG: fine grained grey granite; GGC: grey granite with clay; GYGC:Grey-yellowish granite with clay; DGG: dark grey granite; GRG: grey reddish granite.Alteration degree: 1 — Weakly altered; 2 — Low alteration; 3 — Altered; 4 — Highlyaltered. b) VES P3 inverse model, located over Line 3. The dashed line represents thetrue resistivity versus depth model. The third layer falls below the graphics lower limit.The dotted lines are displayed to help visualization. Current electrode distancecorresponds to AB/2 (m).

Fig. 11. Top: Seismic refraction interpretation of Line 3. Average velocities of P-waves for each spread (receiver layout) are shown. Letters represent the position of shotpoints used inthe refraction interpretation. Location of borehole F4 is indicated. Bottom: Depth-converted seismic reflection section from points EM1 to 8.


electrical conductivity of borehole F17-A was used for interpretationcontrol, its lithological log was not available.

The obtained electromagnetic results for this profile give indica-tions about the existence of altered material and high conductivityfluids in depth. The presence of the latter occurs at the W part of theprofile, where EM values and deep investigation in VES P4 are affectedby the high conductivities of fluids near the decantation basins.Correlation between VES P4 and EM results is acceptable.

Refraction model of Line 4 shows three layers. The first layer hasan average velocity of 770 m/s and it corresponds to the intensivelyaltered zone of the granite. Its thickness ranges from 0–6 m. Thesecond layer corresponds to fractured and altered granite, particu-

Fig. 12. Line 4: Conductivity section of the inverse EM34 model. Units in mS/m

larly between points EM7 and 11 and possesses an average velocityof 1010 m/s. The bottom of this layer dips strongly towards the Wand it reaches a depth of about 23 m in the westernmost part of theLine. In the E part of the refraction profile (points EM7–11) it isdetected at an average depth of about 13 m. The third layer cor-responds to almost unaltered granite, since it shows an averagevelocity of about 4170 m/s, although certainly fractured by unim-portant accidents.

The reflection profile shows a similar structure to the refractionmodel. Keeping in mind that the discontinuity observed near pointEM13 may be an artefact resulting from the lack of shots in this area,between the easternmost part of the profile (point EM12) and point 19

. Location of VES acquired over this Line and borehole F17-A are indicated.

Fig. 13. VES P4, located over Line 4, inverse model. The dashed line represents the trueresistivity versus depth model, with the uppermost layer omitted. The dotted lines aredisplayed to help visualization. Current electrode distance corresponds to AB/2 (m).


(beyond the EM western edge of the profile), the layers inclinetowards the west, just like in the refraction profile.

5. Discussion

5.1. Line 1

According to the surveys results, this line shows a clear disturbancebetween points 14 and 17, with a surface expression in the mapped

Fig. 14. Top: Seismic refraction interpretation of Line 4. Average P-wave velocities for each spused in the refraction interpretation. Location of borehole F17-A is indicated. Bottom: Seism

faults in Figs. 1 and 2. The seismic reflection survey was acquired onlyapproximately between points EM11 and 17 and its interpretationshows a similar structure to the one found with the refraction profile.Seismic horizons dip to depths greater than 20 m towards the NE andthe presence of the above mentioned important deep faults is seenbetween points 15 and 17. The fault zone is composed of two separatefaults around EM points 14–15 and 16–17.

Although there is no indication about screen location in boreholes F11(total depth of 37 mwith water electrical conductivity of 57.1 mS/m) andF12 (total depth66mwith160mS/m), located10maway fromeachother,a hydraulic connection between the shallow alteration zone and theprobable fault identified between points 16 and 17, might exist. This faultismapped in theNNW-SSEdirection inFigs.1 and2and its alterationzonebecomes narrower with depth, until about 60 m (see Fig. 3).

Regarding the observed outcropping fault with WNW-ESE direc-tion, crossing the line perpendicularly at point 15, its depth effectsseem to mix with the other fault. The high shallow conductivitiesregistered between points 15 and 16 are the result of the streamlinethat crosses Line 1 at that point. Water inflows in borehole F12 are,therefore, consistent with water table depth inferred from EM datainterpretation (see Fig. 3).

As seen in the refraction profile (Fig. 5), both faults are clearlymarked and have the strongest expression down to about 40 m depth.Borehole F12 also shows a lithological sequence similar to therefraction profile; below the shallowest 3 m comprising vegetablecoverage, altered “grey granite with quartz fragments”was found until7 m depth, where “grey granite” was crossed, but not detected in therefraction profile. The 3rd seismic horizon is detected in the boreholelog at an 11m depth while the 4th seismic horizon is also detected at a24 m depth. The reason why the “grey granite” layer without waterwas not detected with the refraction interpretation is related with thefact that this layer has a relatively reduced thickness in the boreholelithological log description (5 m). According to this interpretation(which admits that the 2nd seismic horizon corresponds to the

read (receiver layout) and layer are shown. Letters represent the position of shotpointsic reflection section from EM points 12 to 20.


integration of the “grey granite with quartz fragments” and the “greygranite”without water layers), this layer will be even thinner in otherareas of the profile. Since P-velocity waves in the “grey granite” layerwith and without water will not have a significant variation, this is atypical “hidden layer” problem, from which results the nondetectionof the upper thin layer (Palmer, 1980; Telford et al., 1995).

The 4th seismic horizon coincides again with water inflow into theborehole, and, although the borehole does not show changes in thealteration degree, the increase in seismic velocity reflects a change inthe “grey granite” properties that was not detected in borehole F12.Since the true velocity of this 4th seismic horizon is quite lower thanthe apparent velocity measured (4110 m/s) due to large dips of itsinterface, the change of properties from the 3rd to the 4th seismichorizons is quite less pronounced than as suggested by the refractionmodel. This might explain why this change of properties was notdetected in the borehole. As mentioned before, the interface betweenthe 3rd and 4thmodel layers shows very high irregularities, due to thepresence of the two important faults between points EM14–15 andEM16–17.

On the other hand, there is no evidence in depth about the N–Sinterpreted fault crossing Line 1 between points 2 and 3. Shallowconductivity values, higher that 12 mS/m, registered from EM points

Fig. 15. Synthetic conceptual models for each studied line, after a joint interpretation for allgeophysical methods. Solid black lines — Interpreted faults in all used geophysical methodformations. 2— Altered formations. 3— Low altered/fractured to unaltered/unfractured. Deeparea covered only by seismic methods.

1–8 are clearly related with the streamline along the line and withconductive fluid from the old open pit. Between points 12–13 a deepfault was also identified in the reflection profile, in which, consideringhigh electrical conductivity values, may also have fluid circulation. Thelatter is clearly less important than the other features mentionedabove, since it is not mapped in Fig. 1, and therefore, has no surfaceexpression. In the refraction profile, there is no sign of its presence,probably because it was absorbed by the major accident of points 14–15, which is much more important.

5.2. Line 2

The main characteristic of the refraction profile of Line 2 is thelarge depression with high conductivity and low P-wave velocitylocated at the southern part of the profile, beyond point EM12. Sincethe EM profile continues further south than the seismic refractionprofile, the former shows that the depression ends approximately atpoint EM17. Therefore, the seismic profile has not its deeper partconveniently constrained, as expected. The depth reached by this zoneis about 50–60 m either in the EM or the refraction profile.

However, geological mapping stretches the deposits located N and Sfrom these points; the fact that this high conductivity/low seismic

shallow geophysical data. Dashed black lines — Possible faults, not clearly inferred in alls. Numbers in the model correspond to alteration zones: 1 — Highly altered/fractureder faults correspond to the seismic reflection interpretation. Red points in line 4 indicate

Table 2Physical properties attributed to the different layers in the schematic models of Lines 1,2, 3 e 4

Material Characteristics Resistivity(Ω m)

Vp(m/s)

1 Highly altered/fractured granites orclayey-arcosic deposits

b150 400–1500

2 Altered granites 150–1500 1500–40003 Low altered/unfractured granites N1500 N4000

Average values are presented. Vp: Seismic velocity of longitudinal waves.


velocity zone is located close to aN–S orientedprobable fault (see Fig. 2),may indicate that although the profile doesn't cross this fault, it is stillstrongly affected in depth by its presence. Besides the existence of veryhigh electrical conductivity values, the low seismic velocities observedin this zone suggest the presence of a much altered granite zone, sincesuch a fast change in its properties and geometry does not make anincrease of the clayey-arkosic sediments thickness very credible. Theselow seismic velocities include the appearance in the southernpart of theprofile of a superficial layer with a very low velocity of 460 m/s, thedecrease in velocity of the second layer (from1410m/s at theN to900m/s at the south) and the deepening of the third interface of the model,which represents a lateral change of velocity at about a 30–50 m depthfrom 4350 m/s to 2270 m/s. Keeping in mind these considerations, it isassumed that this N–S fault may have significant dimensions.

The NW-SE fault identified near point 5 in the stacked reflectionsection (Fig. 8) does not seem to affect the shallow surface (the first15–20 m). Its presence is also suggested by the deepening of thedeepest interface of the refraction interpretation (Fig. 8) and it isclearly seen in the EM interpretation near point 4 (Fig. 6). Thisstructure may correspond to the mapped fault near point 3 in Fig. 2;the high conductivity zone is particularly visible at point 4, belowapproximately 20–30 m depth, still showing signs of its existence at60 m depth. Further south, the fault interpreted in outcrop near pointEM8 (see Fig. 2) is not visible neither in the refraction profile nor theEM profile. In the reflection stacked section, however, it seems toreach the near surface and it continues in depth until about 60 m. Thisdiscrepancy can be explained by resolution issues of the differentmethods and that the fault does not reach the surface.

The reflection profile was only conducted over refraction spread A.It shows a deepening towards the N of the deepest horizons (belowabout 15 m depth) in the N part of the profile (points 4–5), a high atthe centre of the spread and a new deepening in its southern part (inthis case, also in the shallow horizons). It shows a good coincidencewith the interpretation of the refraction profile.

5.3. Line 3

The most important aspect to highlight in Line 3 regards theconfirmation that the probable fault location mapped in outcropbetween points EM3 and 5 prolongs in depth, but however, accordingto the EMprofile (Fig. 9) and the conductivity section, it does not seem toreach thenear surface. The inexistence of fractureswithwater circulationin the shallowestmeters of borehole F4 (Fig.10a) and theweak electricalconductivity of its water (14.5 mS/m) also support this conclusion.

The interfaces of all geophysical sections (Figs. 9 and 11) arerelatively smooth, except the deepest interface, which presents someimportant irregularities, possibly due to some important fractures.They are located at points EM2–3, 5 and 7, and apparently they don'treach the shallowest 5–6 m. The two faults around point EM5 arecoincident with fractures interpreted with the refraction, reflectionand EM methods, and extend until a few tens of meters in depth.

The two interpreted faults in the seismic reflection section aroundpoint EM5 were apparently integrated in the same fault zone by bothrefraction and EM methods, whose sections show two fault zonescentred in points EM2/3 and 5 extending in depth. A possible fault inpoint EM7 detected with the seismic refraction interpretation doesnot show up either in the reflection profile or in the EM profile andthere are not also evidences of its existence in borehole F4.

5.4. Line 4

The probable fault mapped in outcrop and shown in Figs. 1 and 2,near point EM6 of Line 4 has a deep rooting with a consequentincrease of the conductivity values (Fig. 12). However, it does not seemto be as important as the ones between points EM11 and 14, which arenot visible at the surface. Nevertheless, except for the high

conductivity zones attributed to faults, there is a slight trend for aconductivity “dipping” towards east, which is more visible after points5–6. On the other hand, a shallow alteration zone reaching about 15 mdeep is especially visible in its eastern part.

The refraction model (Fig. 14) shows the third refractor surface isdeepening towards the west (higher EM points), but its surface isrelatively smooth. A layer plunge can be seen at the eastern edge of theprofile, near point EM7. This fact, together with velocities decreaseobserved in spread B in every layer, suggests the presence of a deepfracture beyond point EM7, in accordance with the interpreted fault inoutcrop near point EM6 and the conductivity section. The EM profilealso shows a higher conductivity zone near point EM6. The reflectionprofile (Fig. 14) does not cover this area.

The upper interface of the refraction model is rather irregular,indicating an important fracturing degree in its two shallowest layersor a very irregular alteration surface. The most pronounced irregula-rities show up near points 18–19,Wof the EM profile and about pointsEM10–11. They are accompanied by a decrease of the seismic P-wavesvelocity and therefore, they were interpreted as fractures, while theother irregularities have been attributed to granite alteration andsmall fractures. The fracture located about points EM10–11 isaccompanied by an irregularity in the layer below, so it can beextended in depth. The EM conductivity profile supports thispossibility.

The plunging zoneof the lowaltered/fractured granite (points higherthan EM13), includes the shallow fault interpreted in the seismicreflection section near point 18 (Fig. 14). The corresponding EM profilealso shows a zone with higher conductivities in its western end (pointsEM12–15), just like a low resistivity area is seen in the correspondentsection to the west of point EM11. Therefore, the area betweenapproximately points EM12 and 20 is probably an important faultzone,with an enlarged deformation zone. From the observation of Fig. 2,we can see that the prolongation of two faultsmapped in outcrop to theN and to the S of Line 4 would pass around points EM16–17, whichsuggests that both outcropping faults are in fact the same structure.

6. Conclusions

An integrated interpretation of all results confirmed the previouslymapped faults based on geological outcrop studies and their influencearea. Previously unknown faults were also detected. This study alsoallowed assessing their local importance regarding the groundwatercirculation. Fig. 15 shows a composition of the schematic conceptualmodels of all lines to a depth of about 60 m corresponding to theintegrated interpretation of all used geophysical methods. The modelof Line 3 covers only a depth of 30 m, due to electrical constraints.Each schematic model is a compromise among each method used,since these reflect distinct geophysical properties of the subsurfaceand that are in good agreement with the mapped faults in outcrop ofthe geological maps of Figs. 1 and 2.

In these schematic models, three major layers were defined foreach profile, integrating information from electrical, electromagnetic,seismic refraction, seismic reflection, borehole and lithological data.These layers comprise a wide range of alteration degree, ranging from1 (highly altered formations or clayey-arkosic deposits) to 3 (low


altered and unfractured granites) (see Table 2 and Fig. 15). Thedetected faults are also included in Fig. 15, and their relationship withpreviously mapped in outcrop faults is also highlighted.

The EM, electrical and seismic refraction data showed a goodagreement either in the determination of the physical properties ofthe area, the presence of faults, or the water conductivitiesdistribution related with groundwater flow and its characteristics.Seismic reflection data, though better suited for sedimentaryenvironments (such as those in Profile 2), was useful to complementthe other geophysical information. These results have shown thatthe joint use of these geophysical methods can be successfullyemployed to provide a better understanding of how the geologicalfeatures develop in depth. With these synthetic models and surfacegeological studies, a detailed programme regarding the impermea-bilization of the critical areas can be created so that drainage

problems can be minimized and overcome, allowing the installationof a safe “Waste Containment Deposit” in the old Quinta do BispoMine open pit.

Acknowledgments

The authors acknowledge EDM for allowing the publication of thegeological and geophysical data presented in this manuscript and thehead of the Geophysics Department of the Instituto Nacional deEngenharia, Tecnologia e Inovação, I.P. (INETI), Luís Martins forsupporting this work. The authors also thank the field crew: J. Leote,M. Silva and J. Marquilhas. We are grateful to D. Oliveira for improvingthe English version of the manuscript. The comments and suggestionsof two anonymous referees greatly contributed to improve a firstversion of this paper.

Appendix A

Time–distance curves of the refraction data, with layer interpretation. The interpretation of the different spreads for each line is shown. Offendshots with large offsets are not represented but its curves are plotted. SP— Shotpoints; Geo— geophone number. Distances refer to the first EMpoint.




Appendix B

Travel time data of the refraction profiles. Data for each Spread is shown. Time is in milliseconds. A travel time of zero indicates the arrivalcould not be picked. Distance inmeter, referenced to Shotpoint A. REC#— Receiver number; Pos— Position inm; TTS A— travel time for shotpointA; Layer — number of the layer to which the arrival was attributed in the interpretation presented.

Line 1

Spread A

Shot Pos

A 0B 12C 24D 48E 60F 72G 96

Rec# Pos TTS A Layer TTS B Layer TTS C Layer TTS D Layer TTS E Layer TTS F Layer TTS G Layer

1 1 1 1 18.5 1 25.5 3 32.5 3 37 4 42 4 48.5 42 3 5 1 12 1 24 3 31 3 37 4 40.5 4 47 43 5 6 1 13.5 1 24 3 31 3 35 4 40.5 4 46 44 7 9.5 1 7.5 1 22.5 3 30.5 3 35.5 4 40.5 4 45.5 45 9 13.5 1 3.5 1 23 2 29.5 3 0 0 40 4 0 06 11 18.5 1 3.5 1 21.5 2 28.5 3 34 4 40 4 44 47 13 20 1 3 1 19 2 28.5 3 34 4 38 4 42.5 48 15 23.5 2 3 1 17 2 28.5 3 31.5 3 37 4 42.5 49 17 23.5 2 5 1 12.5 1 27 3 32 3 37 4 41.5 410 19 24.5 2 14 1 8 1 27 3 31.5 3 37 4 41.5 411 21 26.5 2 17.5 2 3.5 1 27 3 31.5 3 36 4 40.5 412 23 28 2 19.5 2 2.5 1 26.5 3 32.5 3 37 4 40.5 413 25 28 2 21 2 2.5 1 26.5 3 30.5 3 36.5 4 40.5 414 27 30 2 23 2 4 1 26 3 31 3 36 3 41 415 29 30 2 24 2 8 1 25.5 2 28 3 34.5 3 40 416 31 31.5 2 24.5 3 16.5 1 23 2 28 3 34 3 39 417 33 31.5 3 25 3 19.5 2 22 2 28 3 32.5 3 39.5 418 35 31.5 3 26 3 21.5 2 21 2 26.5 2 31.5 3 36.5 319 37 32.5 3 25.5 3 23 2 19.5 2 25.5 2 30 3 36 320 39 33 3 26.5 3 23 2 17 1 21.5 2 28.5 3 34 321 41 33 3 27 3 24.5 3 14 1 20.5 2 28.5 3 33 322 43 34 3 26.5 3 25 3 9.5 1 19 2 27.5 2 33 323 45 34.5 3 27.5 3 26 3 5.5 1 16.5 2 26 2 31 324 47 35 3 27.5 3 26 3 3 1 16.5 2 24.5 2 29.5 325 49 35 3 28 3 26.5 3 2.5 1 14 1 23.5 2 29.5 326 51 36 3 29.5 3 27.5 3 3 1 13 1 22 2 29.5 327 53 36.5 3 29.5 3 27.5 3 10 1 10 1 20 2 27 328 55 37.5 3 30.5 3 27.5 3 14 2 7.5 1 20.5 2 26 329 57 38 3 29.5 3 27.5 3 15 2 5.5 1 19 2 25 330 59 38.5 3 30.5 3 29 3 16.5 2 3 1 18 2 24 331 61 39 3 30.5 3 29.5 3 17 2 2.5 1 16 2 23 332 63 39 3 31.5 3 29.5 3 18 2 2.5 1 14.5 1 24 333 65 39.5 3 32 3 30 3 19 2 3.5 1 12.5 1 23 334 67 40 3 32.5 3 30.5 3 19.5 2 6.5 1 9 1 24 335 69 41 3 34.5 3 33 3 21.5 2 11 1 6.5 1 22.5 336 71 41 3 33.5 3 32.5 3 22.5 2 15 2 4 1 22 337 73 43 4 34.5 3 33 3 23 3 16.5 2 2.5 1 21.5 338 75 43.5 4 36 3 34.5 3 23 3 18.5 2 2.5 1 22 339 77 44 4 37 3 34.5 3 24.5 3 21 2 4.5 1 21 240 79 44 4 38.5 4 35.5 4 23.5 3 21 3 9 1 17.5 241 81 44 4 37.5 4 35 4 26.5 3 22 3 10.5 2 15.5 242 83 44 4 36.5 4 37 4 26.5 3 21.5 3 12 2 14 243 85 46.5 4 39.5 4 38 4 27 3 22.5 3 14.5 2 12 244 87 45 4 40 4 38 4 27 3 22.5 3 15.5 2 10.5 145 89 47.5 4 40.5 4 38.5 4 27 3 23 3 19 3 8.5 146 91 47.5 4 40.5 4 39 4 28 3 23.5 3 20 3 7 147 93 47.5 4 40 4 38.5 4 27.5 3 25 3 21 3 3.5 148 95 47 4 41 4 38.5 4 28.5 3 25.5 3 21.5 3 3 1

Line 2

Spread A

A 0B 19C 31D 43E 55

(continued on next page)

Appendix B (continued)

Line 2

Spread A

F 67G 106


1 20 23 3 3 1 20 2 28 2 32.5 2 37.5 3 59 42 22 22 3 4 2 18 2 25.5 2 32 2 37 3 58 43 24 23.5 3 6.5 2 15 2 24 2 28 2 37.5 3 56 44 26 24 3 9 2 13 2 23 2 28 2 33.5 3 57 45 28 23.5 3 10.5 2 12 2 21 2 26 2 32.5 3 53.5 46 30 24 3 12 2 10 2 19.5 2 24 2 32 3 52.5 47 32 24 3 12.5 2 9.5 2 18 2 22.5 2 29.5 3 51.5 48 34 26 3 12.5 2 8 2 17 2 22.5 2 31 3 52 49 36 27 3 14.5 2 6 2 16 2 22.5 2 29.5 3 50.5 410 38 28 3 16 2 4.5 2 15 2 20.5 2 31 3 50.5 411 40 28.5 3 17 2 2.5 2 14 2 19 2 29.5 3 50 412 42 29 3 18.5 2 2 1 12.5 2 19 2 28 3 51 413 44 31 3 20 2 2 1 11.5 2 16 2 28.5 3 50.5 414 46 32.5 3 21 2 2.5 2 10.5 2 15.5 2 26.5 3 49.5 415 48 32 3 23.5 2 5 2 8 2 13.5 2 27.5 3 50.5 416 50 34 3 24 2 6.5 2 6 2 12.5 2 25.5 2 50 417 52 34 3 25 2 9 2 4.5 2 11 2 24.5 2 50 318 54 35.5 3 27 2 10.5 2 2 1 10 2 23 2 48.5 319 56 37 3 28 2 11 2 2 1 9 2 20 2 48 320 58 36.5 3 29 2 12.5 2 3 2 7 2 18 2 47.5 321 60 37.5 3 30 2 14 2 6 2 5 2 18 2 47 322 62 40 3 32 2 15 2 8 2 4 2 15.5 2 45.5 223 64 42 3 33 2 17 2 10 2 3.5 1 14 2 44 224 66 43 3 35 2 19.5 2 12 2 1.5 1 14.5 2 43 2

Spread B

A 28B 67C 79D 91E 103F 115G 154


1 68 30 2 8 2 2 1 18.5 2 44 3 52 4 0 02 70 0 0 11.5 2 3 1 16 2 43.5 3 51 4 51.5 43 72 33.5 2 11.5 2 5.5 1 14.5 2 41.5 3 52 4 49 44 74 34 2 13 2 6 2 12 2 40.5 3 50 4 48 45 76 36.5 2 17.5 2 8.5 2 11 2 40 3 50.5 4 48 46 78 37.5 2 19.5 2 10.5 2 9 2 39 3 51 4 49 47 80 38.5 2 20.5 2 11.5 2 8.5 2 36.5 2 48.5 4 50 48 82 39.5 3 23 2 12 2 6.5 2 34 2 48 4 45.5 49 84 39 3 23.5 2 13.5 2 5 2 32 2 48 4 44 410 86 40 3 24 2 15 2 4.5 2 29.5 2 46 4 44 411 88 41 3 25.5 2 17 2 3.5 2 29.5 2 46 4 41 412 90 42 3 27 2 18 2 2.5 1 27 2 46.5 4 42.5 413 92 43 3 28 2 20 2 2 1 26 2 44.5 4 43 414 94 42.5 3 29.5 2 22 2 4.5 2 24 2 45 4 42 415 96 45 3 31 3 26 2 4.5 2 21 2 43.5 4 42 416 98 46 3 31.5 3 27 2 6 2 18.5 2 42 4 40.5 417 100 47 3 31.5 3 30 2 8 2 19 2 42 4 40 418 102 46 3 35 3 32.5 2 11.5 2 17.5 2 42.5 4 41 419 104 49 3 34 3 34.5 2 13.5 2 14.5 2 42.5 4 41 420 106 50.5 3 36.5 3 37 2 15.5 2 13 2 40.5 3 40.5 421 108 50.5 3 37 3 37 2 16.5 2 12 2 40 3 40.5 422 110 51 3 39 3 39.5 2 20.5 2 10 2 38 3 42 423 112 53.5 3 39 3 40 2 22 2 8 1 36 3 41.5 424 114 55.5 3 41 3 42.5 2 24 2 2.5 1 34 3 41 4

Spread C

A 77B 115C 127D 139E 151F 163G 201



Line 2

Spread C


1 116 35.5 2 22.5 2 19.5 2 31 2 38.5 2 41 3 49 32 118 35.5 2 25.5 2 16.5 2 27 2 34.5 2 38 3 46.5 33 120 40 2 28.5 2 15 2 25 2 37 2 41 3 49.5 34 122 41 2 31.5 2 11 2 23.5 2 37.5 2 39.5 3 49 35 124 44 3 34.5 2 4.5 2 21 2 36 2 39 3 47 36 126 43 3 37 2 3 1 17 2 34 2 36.5 3 45.5 37 128 45.5 3 40 2 3 1 12 2 33.5 2 35.5 3 44.5 38 130 45 3 40.5 3 4 2 10.5 2 30.5 2 36 3 44 39 132 47 3 43.5 3 10 2 5.5 2 29.5 2 34 2 42.5 310 134 46.5 3 42.5 3 11 2 3.5 2 28.5 2 32 2 42.5 311 136 48.5 3 45 3 16.5 2 2.5 2 25.5 2 30.5 2 43 312 138 47 3 44.5 3 20.5 2 2 1 25.5 2 30 2 41.5 313 140 51.5 3 47 3 23.5 2 3 1 23.5 2 28 2 40 314 142 55 3 46.5 3 27.5 2 4.5 2 20.5 2 26 2 36 215 144 55.5 3 49 3 31 2 5 2 17 2 28.5 2 34.5 216 146 59.5 3 48 3 34 2 5.5 2 13.5 2 26 2 33 217 148 61 3 48 3 37.5 2 10.5 2 15.5 2 24.5 2 31 218 150 62 3 48 3 41.5 2 15 2 12.5 2 22.5 2 27.5 219 152 59 3 46.5 3 43.5 2 17.5 2 10.5 2 21 2 26 220 154 57.5 3 44 3 37 2 18.5 2 8.5 2 17 2 22 221 156 57 3 42.5 3 37 2 16.5 2 6.5 2 15.5 2 20 222 158 57 3 41.5 3 36 2 16.5 2 2.5 2 13.5 2 20.5 223 160 58 3 44 3 36.5 2 19 2 2 2 13 2 18.5 224 162 59 3 0 0 38 2 19.5 2 1.5 1 10 2 18 2

Line 3

Spread A

A 10B 39.3C 48.3D 57.3E 66.3F 75.3G 114.5


1 40 27.5 3 2 1 15 2 22.5 2 27 3 20.5 3 46 42 41.5 28.5 3 3.5 2 12.5 2 21 2 27 3 21 3 44.5 43 43 28.5 3 4.5 2 9 2 20 2 25.5 3 19.5 3 44 44 44.5 30 4 8.5 2 7 2 19 2 25 3 20.5 3 44 45 46 30 4 9 2 7.5 2 16.5 2 23.5 3 19 3 42.5 46 47.5 31 4 11.5 2 1.5 1 16 2 22.5 3 19.5 3 41.5 47 49 31.5 4 13 2 2 1 12 2 22 3 18 3 41.5 48 50.5 33.5 4 16.5 2 4.5 1 11 2 23 3 18.5 3 40.5 49 52 32.5 4 17 2 8 2 7 2 20.5 3 17.5 3 42.5 410 53.5 34 4 19.5 2 9 2 8 2 20.5 2 18 3 44 411 55 34.5 4 19 3 10.5 2 2.5 2 17.5 2 16.5 3 43 412 56.5 35.5 4 19.5 3 12.5 2 2 1 15.5 2 14.5 3 41 413 58 34 4 21 3 13.5 2 2 1 13 2 14 2 41.5 414 59.5 34.5 4 23.5 3 17.5 2 3 2 10.5 2 11.5 2 40.5 415 61 36 4 24 3 19.5 2 5.5 2 8.5 2 10.5 2 40 416 62.5 35 4 27 3 20 2 11 2 5.5 2 9 2 42 417 64 37 4 27.5 3 23.5 3 14.5 2 3.5 2 7.5 2 0 018 65.5 37 4 25.5 3 23.5 3 16.5 2 3 1 9 2 39.5 319 67 36 4 25 3 24.5 3 17.5 2 4.5 1 8.5 2 39.5 320 68.5 34.5 4 26 3 23 3 17 2 4 2 5 2 38 321 70 35 4 26 3 25 3 21.5 2 6.5 2 5 2 38 322 71.5 34 4 25.5 3 24.5 3 22 2 8 2 3 2 37.5 323 73 35 4 27 3 26.5 3 21 2 10.5 2 4 2 37.5 324 74.5 36.5 4 27.5 3 27.5 3 23 2 11 2 4 1 36.5 3

Spread B

A 46B 75.3C 84.3D 93.3E 102.3F 111.3G 150.5


1 76 32.5 3 1.5 1 10 2 22.5 2 34 3 36 3 47.5 42 77.5 33.5 3 5 1 8.5 2 20.5 2 33.5 3 35.5 3 44 4

(continued on next page)



Line 3

Spread B


3 79 33.5 3 6.5 2 6.5 2 17.5 2 31 3 34.5 3 44.5 44 80.5 32.5 3 7 2 6 2 16.5 2 30.5 3 34 3 44 45 82 32 3 9.5 2 4.5 2 20 2 33.5 3 35.5 3 46 46 83.5 34 3 10 2 2.5 1 14.5 2 34 3 35.5 3 46 47 85 35.5 3 11 2 3.5 1 11.5 2 36 3 34.5 3 43.5 48 86.5 37.5 3 11.5 2 3 2 11.5 2 34.5 3 32.5 3 44 49 88 37.5 3 13.5 2 4.5 2 7.5 2 31.5 3 33.5 3 44 410 89.5 39.5 3 18 2 8.5 2 6 2 28.5 3 37 3 46 411 91 40.5 3 18 2 9 2 3 2 25.5 3 35 3 43.5 412 92.5 40 3 19.5 2 10.5 2 2.5 1 21 2 32.5 3 44 413 94 42 3 22 2 12.5 2 3 1 18 2 30 3 44.5 414 95.5 44.5 4 24 2 14 2 4.5 2 15 2 29 3 44 415 97 43.5 4 27 2 18 2 5.5 2 11.5 2 23.5 3 43.5 416 98.5 43 4 28.5 3 18.5 2 8 2 8 1 21.5 3 43 417 100 45.5 4 30.5 3 22.5 2 11 2 2.5 1 20.5 2 43 418 101.5 46 4 30.5 3 24.5 2 13 2 2 1 16 2 41.5 319 103 46.5 4 31.5 3 26 2 15.5 2 1.5 1 13 2 41 320 104.5 44.5 4 31.5 3 29 3 18.5 2 4.5 1 12 2 40.5 321 106 46.5 4 32.5 3 29 3 19.5 2 11 2 10.5 2 41 322 107.5 46.5 4 32 3 32.5 3 24 2 12 2 6.5 1 40.5 323 109 46.5 4 33.5 3 33.5 3 27 2 17 2 5.5 1 37 324 110.5 46 4 33.5 3 31 3 28.5 2 17.5 2 3.5 1 37.5 3

Line 4

Spread A

A 0B 12C 36D 48E 60F 84G 96


1 1 3 1 20 1 48.5 2 54.5 3 53 3 54.5 3 0 02 3 5 1 15.5 1 47.5 2 54 3 51.5 3 54 3 57 33 5 7.5 1 11 1 46.5 2 53.5 3 50.5 3 51.5 3 56 34 7 12.5 1 7 1 45.5 2 53.5 3 50 3 51 3 55 35 9 18 1 4.5 1 44.5 2 52 3 49.5 3 50.5 3 53.5 36 11 25 1 1.5 1 42.5 2 51 3 47.5 3 50.5 3 52.5 37 13 28 1 1.5 1 41.5 2 50 3 47 3 48.5 3 51 38 15 29.5 1 4 1 38 2 48.5 3 47.5 3 47.5 3 50 39 17 33.5 1 5 1 40 2 47 3 46.5 3 47 3 50 310 19 37.5 1 10.5 1 33.5 2 46.5 2 45.5 3 46.5 3 50 311 21 42 1 15 1 30 1 44.5 2 45 3 46.5 3 50 312 23 45.5 1 18 1 23 1 41.5 2 44 2 46 3 49 313 25 47.5 2 23 1 20.5 1 39 2 42 2 43 3 47 314 27 48.5 2 26.5 1 14 1 36.5 2 41 2 44 3 46 315 29 49 2 29 1 6.5 1 33 2 37.5 2 45 3 45.5 316 31 50 2 36 1 8.5 1 29 2 40.5 2 43.5 3 45.5 317 33 51.5 2 38.5 1 3 1 25.5 1 40 2 43.5 3 45 318 35 49.5 2 42 2 1 1 19 1 39.5 2 42 3 43.5 319 37 51.5 2 44 2 1 1 14 1 36 2 41.5 3 43 320 39 51.5 2 43 2 2.5 1 9.5 1 31.5 2 40.5 3 42.5 321 41 51 2 45 2 6 1 6.5 1 30 2 40.5 3 42 322 43 52 2 44.5 2 7.5 1 4 1 30.5 1 40 3 42.5 323 45 51 3 43.5 2 9.5 1 2.5 1 26.5 1 39 3 42 324 47 50.5 3 44.5 2 12.5 1 1.5 1 17 1 38.5 3 41.5 325 49 51.5 3 45 2 14.5 1 2 1 15 1 38 3 41 326 51 51.5 3 45.5 2 20.5 1 4.5 1 12 1 37.5 3 41.5 327 53 54 3 45.5 2 20.5 1 4.5 1 7.5 1 37 2 40.5 328 55 53.5 3 46.5 2 22.5 1 7.5 1 4 1 35.5 2 41 329 57 56 3 47.5 2 23 1 9 1 3.5 1 34 2 40 230 59 53.5 3 48 3 32.5 2 11 1 1.5 1 32.5 2 38.5 231 61 54 3 48.5 3 33.5 2 14 1 1 1 31.5 2 36.5 232 63 55 3 48.5 3 36.5 2 17 1 3 1 29.5 2 36 233 65 55.5 3 47 3 39 2 18 1 5 1 28.5 2 36 234 67 54 3 49.5 3 40.5 2 24 1 4.5 1 19 1 35 235 69 56.5 3 49 3 41.5 3 34 1 7 1 16 1 33 236 71 57 3 49.5 3 41 3 37 2 10.5 1 12 1 31 237 73 55.5 3 50.5 3 41.5 3 36.5 2 14 1 10 1 29.5 238 75 54.5 3 49.5 3 42 3 41.5 2 17.5 1 10 1 30 2



Line 4

Spread A


39 77 56.5 3 49 3 42.5 3 45 2 23 1 8 1 29 240 79 57 3 47.5 3 40 3 47 2 27.5 1 5.5 1 27 241 81 54.5 3 48 3 40.5 3 47.5 2 29.5 1 2.5 1 23.5 142 83 55.5 3 49 3 41.5 3 48 2 32.5 2 2 1 12.5 143 85 55.5 3 0 0 40 3 45 2 34.5 2 2.5 1 10 144 87 57 3 49 3 41.5 3 47.5 2 34.5 2 3 1 9.5 145 89 58 3 49 3 42 3 47.5 2 35.5 2 5 1 7.5 146 91 57.5 3 51 3 41 3 48 2 36 2 6.5 1 5.5 147 93 58.5 3 52.5 3 41.5 3 47 2 36.5 2 7.5 1 4 148 95 56.5 3 52 3 42.5 3 49 2 37 2 10 1 3.5 1

Spread B

A 57B 96C 108D 120E 132F 144G 183


1 97 38.5 2 1.5 1 20 2 33.5 2 46.5 3 44 3 38.5 32 99 41.5 2 3 1 16 2 30.5 2 43 3 45 3 38 33 1 41.5 3 6.5 2 11.5 2 29 2 40.5 3 43.5 3 36.5 34 3 41.5 3 6.5 2 7.5 2 26 2 42 3 44 3 36 35 5 41 3 12 2 3.5 2 25.5 2 43.5 3 43.5 3 37 36 7 42.5 3 14.5 2 3 1 22 2 40.5 3 43.5 3 37 37 9 42.5 3 15.5 2 3 1 17.5 2 37 3 44 3 36.5 38 11 43.5 3 18.5 2 3.5 2 12 2 35 3 43.5 3 37.5 39 13 43.5 3 21.5 2 6.5 2 11 2 33.5 3 43 3 36 310 15 46 3 25.5 2 8.5 2 5 2 24.5 2 44.5 3 37 311 17 45.5 3 28 2 10 2 4 2 22 2 46.5 3 37.5 312 19 47 3 30 2 13 2 3.5 1 18.5 2 38 3 39 313 21 47.5 3 31.5 2 19 2 2.5 1 17 2 38 3 37 314 23 48.5 3 32.5 3 20 2 4.5 2 12.5 2 39 3 38 315 25 49.5 3 33 3 22 2 5.5 2 9 2 30.5 2 37 316 27 50.5 3 35.5 3 27.5 2 11.5 2 6.5 2 25.5 2 36.5 317 29 52 3 37 3 27 2 11.5 2 5.5 2 20 2 37 318 31 52 3 35.5 3 30 2 16 2 4 1 18.5 2 37 319 33 51 3 35.5 3 38 3 18 2 4 1 16 2 36.5 320 35 51.5 3 35.5 3 43 3 21.5 2 5 2 13 2 37 321 37 51 3 34.5 3 39 3 24 2 6.5 2 10 2 36 322 39 53 3 36.5 3 39.5 3 27 2 10 2 7.5 2 35.5 323 41 54.5 3 38 3 41 3 31.5 2 12.5 2 5.5 2 35 324 43 55.5 3 39.5 3 42 3 31.5 2 15 2 4 1 35.5 3

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