Short−term survival of ammonites in New Jersey after the ... · Ammonites include Pachydiscus (Neodesmoceras) mokotibensis, Sphenodiscus lobatus , Eubaculites carinatus , E. latecarinatus

Shortminusterm survival of ammonites in New Jerseyafter the endminusCretaceous bolide impact

NEIL H LANDMAN MATTHEW P GARB REMY ROVELLI DENTON S EBEL

and LUCY E EDWARDS

Landman NH Garb MP Rovelli R Ebel DS and Edwards LE 2012 Shortminusterm survival of ammonites in NewJersey after the endminusCretaceous bolide impact Acta Palaeontologica Polonica 57 (4) 703ndash715

A section containing the CretaceousPaleogene (= CretaceousTertiary) boundary in Monmouth County New Jersey preminusserves a record of ammonites extending from the end of the Cretaceous into possibly the beginning of the Danian The secminustion includes the upper part of the Tinton Formation and lower part of the Hornerstown Formation The top of the TintonFormation is represented by a richly fossiliferous unit (the Pinna Layer) that contains many bivalves in life position as wellas ammonite jaws preserved inside body chambers Ammonites include Pachydiscus (Neodesmoceras) mokotibensisSphenodiscus lobatus Eubaculites carinatus E latecarinatus Discoscaphites iris D sphaeroidalis D minardi and Djerseyensis The Pinna Layer probably represents a relatively short interval of time lasting tens to hundreds of years it isconformably overlain by the Burrowed Unit which contains a single fragment of Discoscaphites sp and several fragmentsof E latecarinatus as well as several isolated specimens of ammonite jaws including two of Eubaculites Examination ofthe mode of preservation of the ammonites and jaws suggests that they were fossilized during deposition of the BurrowedUnit and were not reworked from older deposits Based on the ammonites and dinoflagellates in the Pinna Layer and theBurrowed Unit these strata traditionally would be assigned to the uppermost Maastrichtian corresponding to calcareousnannofossil Subzone CC26b However a weak iridium anomaly (500ndash600 pgg) is present at the base of the Pinna Layerwhich presumably represents the record of the bolide impact Correlation with the iridium layer at the Global Stratotype Secminustion and Point at El Kef Tunisia would therefore imply that these assemblages are actually Danian provided that the iridminusium anomaly is in place and the ammonites and dinoflagellates are not reworked If the iridium anomaly is in place or evenif it has migrated downward from the top of the Pinna Layer the ammonites would have survived the impact at this site for abrief interval of time lasting from a few days to hundreds of years

Key words Ammonoidea biostratigraphy extinctions iridium anomaly CretaceousPaleogene boundary New Jersey

Neil H Landman [landmanamnhorg] Division of Paleontology (Invertebrates) American Museum of Natural Hisminustory 79th Street and Central Park West New York NY 10024 USAMatthew P Garb [mgarbbrooklyncunyedu] Department of Earth and Environmental Sciences Brooklyn Collegeand Graduate School of the City University of New York Brooklyn NY 11210 USARemy Rovelli [remyrovelligmailcom] Department of Earth and Environmental Sciences Brooklyn College BrooklynNY 11210 USADenton S Ebel [debelamnhorg] Division of Earth and Planetary Sciences American Museum of Natural History 79th

Street and Central Park West New York NY 10024 USALucy E Edwards [leedwardusgsgov] United States Geological Survey Mail Stop 926A Reston VA 20192 USA

Received 9 June 2011 accepted 18 December 2011 available online 24 February 2012

Copyright copy 2012 NH Landman et al This is an openminusaccess article distributed under the terms of the Creative Comminusmons Attribution License which permits unrestricted use distribution and reproduction in any medium provided theoriginal author and source are credited

IntroductionThe endminusCretaceous extinctions have convincingly been atminustributed to an asteroid impact (Schulte et al 2010) Ammominusnites may have briefly survived this event based on studies ofstratigraphic sections in the Netherlands (Smit and Brinkhuis1996 Jagt et al 2003 Machalski et al 2009) and Denmark(Machalski and Heinberg 2005) While this contradicts earminuslier suppositions about the nature of the extinctions at the

erathem boundary it is perhaps more consistent with expecminustations about the response of communities to catastrophicperturbations However such claims need to be carefullydocumented on the basis of detailed stratigraphic paleontominuslogic sedimentologic taphonomic and geochemical work(Machalski and Heinberg 2005) It is essential to differentiminusate ammonites that were fossilized at the time of depositionof the surrounding sediment versus those that were reworkedfrom older deposits

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Landman et al (2007a 2010a) investigated outcrops inMonmouth County New Jersey that contain ammonites anddinoflagellates associated with an iridium anomaly These fosminussils are traditionally assigned to the uppermost Maastrichtianbut appear above the iridium anomaly suggesting that theymay actually be Danian The fossils occur in two layers thelower layer known as the Pinna Layer is very fossiliferousand has been thoroughly documented by Landman et al(2007a 2010a) The upper layer known as the Burrowed Unitcontains a depauperate assemblage of ammonites and dinominusflagellates and has received much less attention In this paper

we focus on the ammonites in this unit to determine if theywere fossilized at the time of deposition of the surrounding sedminusiment having lived andor died during this time interval or ifthey were reworked from older deposits The ultimate explanaminustion of the sequence of events at this site depends however onwhether the iridium anomaly represents the record of the bolideimpact and if so whether it is in place or has migrated downminusward (Landman et al 2007a Miller et al 2010)

Institutional abbreviationsmdashAMNH American Museum ofNatural History New York USA MAPS Monmouth Amaminusteur Paleontological Society Long Branch New Jersey

704 ACTA PALAEONTOLOGICA POLONICA 57 (4) 2012

Fig 1 Stratigraphic section in the Manasquan River Basin Monmouth County New Jersey A The top of the Tinton Formation consists of the Pinna Layeroverlain by the Burrowed Unit which is overlain in turn by the Hornerstown Formation An enriched concentration of iridium occurs at the base of thePinna Layer (indicated by the stars) The position of the CretaceousPaleogene boundary in this figure is based on the assumption that the enriched concenminustration of iridium is in place B Iridium profile from two sites (represented by the solid and dashed lines) in the Manasquan River Basin (Landman et al2007a) C Map of part of New Jersey showing localities mentioned in the text 1 Manasquan River Basin 2 Buckrsquos Pit 3 Ivanhoe Creek

Geological settingSediments spanning the CretaceousPaleogene (= CretaceousTertiary) boundary in New Jersey crop out in a belt extendingfrom the Sandy Hook embayment in the northeast to the Delaminusware embayment in the southwest These sections have beenextensively investigated in both surface exposures and cores(Minard et al 1969 Gallagher 1993 Olsson et al 1997Owens et al 1998 Landman et al 2004a b Miller et al2004) The study area of this report is in the upper ManasquanRiver Basin Monmouth County and occupies approximately65 km2 (Fig 1) The stratigraphic section has been describedby Landman et al (2007a) and is slightly modified in this paminusper The section consists of approximately 2 m of the TintonFormation overlain by 2 m of the Hornerstown Formation(Fig 1)

Material and methodsBulk samples were extracted from the Pinna Layer Burminusrowed Unit and Hornerstown Formation Approximately 90kg of Burrowed Unit were processed The samples were alminuslowed to dry and were then broken down in the lab usingsmall chisels picks and a small rock crusher In the Burminusrowed Unit the material forming the burrows was carefullyseparated from the surrounding matrix The location of fosminussils in the Burrowed Unit was recorded relative to the posiminustion of the burrows Fossils were extracted using scalpels raminuszors and pliers and identified down to species level wherminusever possible Fossils are reposited at the American Museumof Natural History (AMNH) and the Monmouth AmateurPaleontological Society (MAPS)

The grain size distribution of the sediments was analyzedas described in Landman et al (2007a) It is important to emminusphasize that much of the sediment consists of large glauconiticpellets composed of mud Therefore the reported grain sizedistribution does not necessarily reflect the original muddycomposition of the sediment as it accumulated on the sea floor

DescriptionPinna LayermdashThis unit is approximately 20 cm thick and islaterally extensive (Fig 1) It is grayish green on fresh expominussures and orangeminusbrown on weathered exposures It consists of62 mud and 38 coarser sediments It is finely bioturbatedwithout any evidence of bedding Although it is homogeminusneous it tends to break along horizontal planes All of the fosminussils are internal and external molds without any calcareousshell preserved In general the internal molds are composed ofglauconitic minerals and weather orangeminusbrown However asmall percentage of them (approximately 10) are composedof sideritic clay They are more indurated than the surroundingsediment and weather orangeminustan

The Pinna Layer is very fossiliferous and contains approxminusimately 110 species of bivalves gastropods cephalopodsechinoids sponges serpulids bryozoans crustaceans anddinoflagellates as reported in Landman et al (2007a 2010a)Bivalves are the most common invertebrates both in terms ofnumbers of species and numbers of individuals especiallyCucullaea vulgaris Morton 1830 The ammonites includePachydiscus (Neodesmoceras) mokotibensis Collignon 1952Sphenodiscus lobatus (Tuomey 1856) Eubaculites carinatus(Morton 1834) E latecarinatus (Brunnschweiler 1966)Discoscaphites iris (Conrad 1858) D sphaeroidalis Kenminusnedy and Cobban 2000 D minardi Landman Johnson andEdwards 2004a and D jerseyensis Landman Johnson GarbEdwards and Kyte 2007a (Fig 2) This assemblage of ammominusnites is characteristic of the uppermost Maastrichtian D irisZone This zone is also present in other parts of the US Gulfand Atlantic Coastal Plains (Stephenson 1955 Hansen et al1993 Kennedy and Cobban 2000 Landman et al 2004a b)

The dinoflagellates in the Pinna Layer are abundant andvery diverse and include Palynodinium grallator Gocht1970 Thalassiphora pelagica (Eisenack 1954) Eisenackand Gocht 1960 Deflandrea galeata (LejeuneminusCarpentier1942) Lentin and Williams 1973 and Disphaerogena carminusposphaeropsis Wetzel 1933 This assemblage of dinoflagelminuslates is characteristic of the uppermost Maastrichtian Palynominusdinium grallator Zone probably the Thalassiphora pelagicaSubzone of Schioslashler and Wilson (1993) which correlateswith the upper part of calcareous nannofossil SubzoneCC26b (Edwards et al 1999 Landman et al 2004a b) Thusthe age of the dinoflagellates is consistent with that of theammonites in the same unit

Many fossils in the Pinna Layer appear in clustersCucullaea vulgaris is very abundant and occurs in largeconcentrations with most specimens articulated Echinoidsoccur in aggregations of hundreds of individuals Surprisminusingly baculites and scaphites also appear as monospecificclusters of as many as 30 specimens Pinna laqueataConrad 1858 (after which the layer is named) is almost alminusways preserved in vertical life position It occasionally apminuspears in clusters but never forms a dense framework Jawsof Discoscaphites occur both as isolated specimens and inminusside body chambers

Burrowed UnitmdashThe Pinna Layer is conformably overlainby the Burrowed Unit which is 15ndash20 cm thick (Fig 1) Thematrix of the Burrowed Unit is similar to that of the PinnaLayer and consists of glauconitic pellets and nonminusglaucominusnitized clay The most distinctive feature of the BurrowedUnit is the presence of large Thalassinoides burrows thatpipe down material from the overlying Hornerstown Formaminustion In fresh exposures the matrix of the Burrowed Unit islight grayish green and the burrows are dark grayish green Inweathered exposures the matrix is orangeminusbrown and theburrows are dark greenish black The burrows are very largeeg 10 cm long by 25 cm wide They form an extensive

httpdxdoiorg104202app20110068

LANDMAN ET ALmdashPOSTminusCRETACEOUS AMMONITES IN NEW JERSEY 705


anastomozing complex but rarely penetrate into the PinnaLayer usually turning sideways at the contact

In contrast to Landman et al (2007a 2010a) we considerthe Burrowed Unit as the top of the Tinton Formation ratherthan the base of the Hornerstown Formation because the liminusthology and fauna of the Burrowed Unit are more similar tothose of the Pinna Layer than to those of the HornerstownFormation For example the Burrowed Unit consists of 55mud the Pinna Layer 62 mud and the Hornerstown Forminusmation 38 mud In addition the glauconitic pellets in theBurrowed Unit are mostly light pale green or tan as in thePinna Layer whereas they are greenish black shiny andbotryoidal in the Hornerstown Formation

The Burrowed Unit is much less fossiliferous than thePinna Layer (Fig 3 Table 1) The fossils are internal and exminusternal molds without any calcareous shell In general the inminusternal molds are composed of glauconitic pellets and weatherorangeminusbrown Occasionally however they are composed ofsideritic clay and are more indurated than the surroundingsediment The clay is the same color as that in the matrixFossils also occur inside and adjacent to the burrows and arepiped down from the overlying Hornerstown Formation

The Burrowed Unit contains approximately 20 species ofbivalves gastropods cephalopods echinoids bryozoanscrustaceans and dinoflagellates (Fig 3 Table 1) The mostcommon fossils are Pecten venustus Morton 1833 andMargaritella pumila Stephenson 1941 We have recordedonly a single specimen of Cucullaea vulgaris in contrast toits abundance in the Pinna Layer None of the bivalves occurin life position All of them are disarticulated except for onespecimen of Granocardium sp (Fig 3L)

Most significantly the Burrowed Unit differs from thePinna Layer in the paucity and fragmentary preservation ofthe ammonites and dinoflagellates There is only a single fragminusment of Discoscaphites sp (Fig 3E) and five fragments ofEubaculites latecarinatus (Fig 3AndashD) All of the specimensof E latecarinatus are small with a maximum whorl height of18 mm and a maximum length of 47 mm For exampleAMNH 64419 is a piece of a body chamber 32 mm long oriminusented in a vertical position and terminating in a burrow (Fig3B) It is composed of glauconite but is slightly sideritized onthe edges and retains a faint trace of iridescent shell

The Burrowed Unit also contains two light tan clay podsboth of which are adjacent to burrows The pods are moreindurated than the surrounding sediment One pod bears a

specimen of Heteropora americana Richards 1962 withoutany sediment in its zooids (Fig 4C) and three small fragminusments of Eubaculites latecarinatus that are oriented parallelto each other (Fig 4A) One of these fragments contains asmall telescoped specimen of Eubaculites inside (Fig 4B)The other pod bears two hollow fragments of E latecariminusnatus (Fig 4D E) and a fragment of H americana

The most surprising finds in the Burrowed Unit are amminusmonite aptychi (= lower jaws) (Fig 5) Five aptychi are presminusent all of which occur as isolated specimens They weatherorange brown and are surrounded by the matrix of the Burminusrowed Unit Two of the aptychi are long rectangular andnearly flat (Fig 5A D) The ratio of length to width in thesetwo specimens ranges from 25 to 26 The commissure islong and straight and the surface is covered with fine comminusmarginal lirae Based on comparisons with aptychi in Landminus



Table 1 Invertebrate fossils in the matrix of the Burrowed Unit at the topof the Tinton Formation Monmouth County New Jersey The authorsof the species are listed in Landman et al (2007a table 1)

Bivalvia Anatimya lataCrenella sericaCucullaea vulgarisEriphyla decemnariaGranocardium spOstrea tecticostaPecten argillensisPecten venustusPycnodonte sp

Gastropoda Anchura spArrhoges spCalliomphalus spMargaritella pumilaTrachytriton holmdelense

Cephalopoda Discoscaphites spEubaculites latecarinatusjaws of Eubaculites and Discoscaphites

Echinodermata echinoid spines

Arthropoda crab bits

Annelida Hamulus squamosusLongitubus lineatus

Coelenterata Micrabacia sp

Dinoflagellata Dinogymnium spunidentifiable fragments

Fig 2 Fossils in the Pinna Layer near the top of the Tinton Formation Monmouth County New Jersey A Pachydiscus (Neodesmoceras) mokotibensisCollignon 1952 MAPS A2051a1 in right lateral view BndashE Discoscaphites iris (Conrad 1858) B MAPS A2060b1 accumulation of juvenile specimensC MAPS A2058b3 cluster of adult microconchs D AMNH 50540 adult macroconch in right lateral view E MAPS A2060b9 adult microconch in rightlateral view F MAPS A3601g3 accumulation of echinoids G H Discoscaphites sphaeroidalis Kennedy and Cobban 2000 G AMNH 50752 adultmacroconch in right lateral view H AMNH 50713 adult microconch in right lateral view I Discoscaphites jerseyensis Landman Johnson Garb Edminuswards and Kyte 2007a AMNH 50393 adult macroconch in right lateral view J Discoscaphites minardi Landman Johnson and Edwards 2004a AMNH50411 adult macroconch in right lateral view K L Discoscaphites iris K MAPS A2060b11 lower jaw preserved inside the body chamber in right lateralview L MAPS A2062a8 closeminusup of lower jaw inside the body chamber M Sphenodiscus lobatus (Tuomey 1856) MAPS A2002g2 in left lateral viewN Pinna laqueata Conrad 1858 MAPS A2402p2 in vertical life position O P Eubaculites latecarinatus (Brunnschweiler 1966) O AMNH 51877adult microconch in right lateral view P AMNH 51888 adult macroconch in right lateral Q Eubaculites carinatus (Morton 1834) MAPS A2058b1adult macroconch in right lateral view


B

E

M

C

KG H

Q

I J

N O P

R S T U V

3AA1 2AD1 2D 3D F1 F2

L1

3L

2L

Fig 3 Fossils in the Burrowed Unit at the top of the Tinton Formation and in the overlying Hornerstown Formation Monmouth County New JerseyAndashQ Fossils in the matrix of the Burrowed Unit nonminusreworked AndashD Eubaculites latecarinatus (Brunnschweiler 1966) A AMNH 72338 in dorsal (A1)right lateral (A2) and ventral (A3) views B AMNH 64419 in lateral view C AMNH 69508 in lateral view D AMNH 73321 in left lateral (D1) dorsal(D2) and ventral (D3) views E Discoscaphites sp AMNH 69499 in ventral view in matrix adjacent to burrow F Anchura sp AMNH 69506 internalmold (F1) impression (F2) G Margaritella pumila Stephenson 1941 AMNH 72348 H Trachytriton holmdelense Whitfield 1892 AMNH 72315



C

A

800 microm 200 microm


5 mm10 mm 10 mm

D1 D2

E1 E2

Fig 4 Clay pods in the matrix of the Burrowed Unit adjacent to burrows Monmouth County New Jersey probably reworked from the Pinna Layer andpiped down into the Burrowed Unit AndashD Single pod adjacent to a burrow A Overview B Eubaculites latecarinatus (Brunnschweiler 1966) AMNH66312 in left lateral view (B1) whorl crossminussection at adoral end showing a specimen of Eubaculites telescoped inside (B2) C Heteropora americana Richminusards 1962 AMNH 51309 without any sediment in the zooids D Eubaculites sp hollow specimen AMNH 66313 view of hollow chambers (D1)closeminusup of septum (D2) E Eubaculites sp in another clay pod adjacent to a burrow AMNH 66314 septal face (E1) closeminusup of septal neck (E2)

I Arrhoges sp AMNH 69525 J Eriphyla decemnaria (Conrad 1869) AMNH 72310 K Pecten venustus Morton 1833 AMNH 72353 L Granominuscardium sp AMNH 72340 in the matrix (L1) lateral (L2) and umbonal (L3) views M Pecten argillensis Conrad 1869 AMNH 72316 N Anatimya lata(Whitfield 1886) AMNH 72339 O Cucullaea vulgaris Morton 1830 AMNH 72303 P Hamulus squamosus Gabb 1859 AMNH 72323 Q Unidentiminusfied microfossil AMNH 66332 RndashV Fossils in the burrows of the Burrowed Unit representing material piped down from the basal Hornerstown Formaminustion R Euspira sp AMNH 69515 eworked S Turritella sp AMNH 72322 reworked T Pecten venustus AMNH 72325 nonminusreworked U Grypminushaeostrea vomer Morton 1828 AMNH 72349 nonminusreworked V Ostrea pulaskensis Harris 1894 AMNH 72351 nonminusreworked Scale bars 5 mm exceptindicated otherwise

man et al (2007b) these specimens probably belong toEubaculites and as such are the first aptychi of Eubaculitesever reported from North America The other three aptychiare more convex and nearly triangular in shape (Fig 5B C)They probably belong to Discoscaphites by comparisonwith Landman et al (2007a 2010b)

Dinoflagellates are very rare in the Burrowed Unit Otherthan some unidentifiable fragments we only recorded a sinminusgle specimen of Dinogymnium sp which is generally conminus

sidered to be Cretaceous The ammonites although scarcesuggest that the Burrowed Unit is the same age as the PinnaLayer However it is evidently younger than the Pinna Layerinasmuch as it occurs above this unit

Hornerstown FormationmdashThe contact between the matrixof the Burrowed Unit and the overlying Hornerstown Formaminustion is sharp However the contact between the burrows ofthe Burrowed Unit and the overlying Hornerstown Formaminus


A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2

Fig 5 Ammonite aptychi (= jaws) in the matrix of the Burrowed Unit A D Lower jaws attributed to Eubaculites A AMNH 69496 right valve D AMNH69492 view of right valve (D1) closeminusup of aptychus at the anterior end (D2) B C Lower jaws attributed to Discoscaphites B AMNH 69497 left valveC AMNH 69498 left valve

tion is difficult to pinpoint which is part of the reason whywe initially assigned the Burrowed Unit to the base of theHornerstown Formation (Fig 1) The Hornerstown Formaminustion consists of 38 mud and 62 coarser sediments It isdark grayish green in fresh exposures and dark green to blackin weathered exposures

The fossils in the Hornerstown Formation show two difminusferent modes of preservation In the first mode internalmolds are composed of whitish clay surrounded by darkgreen glauconitic pellets (Fig 3R S) The clay is induratedand much lighter in color than that in the Pinna Layer orBurrowed Unit These fossils include Cucullaea vulgarisEuspira sp Turritella sp Eubaculites latecarinatus andDiscoscaphites iris Many of these fossils also occur in the

burrows that extend into the Burrowed Unit We interpretthese fossils as having been reworked from older depositsThey are accompanied by siderite nodules most of whichare unfossiliferous However some nodules contain poorlypreserved dinoflagellate cysts and Rugubivesiculites pollen(Landman et al 2007a 40) supporting the interpretationthat the nodules were also reworked

The other group of fossils weather pinkish brown possiminusbly reflecting diagenetically altered shell (Fig 3TndashV) Weinterpret these fossils as having formed during deposition ofthe Hornerstown Formation The fauna is very depauperateconsisting of only 15 species including Gryphaeostreavomer Morton 1834 as well as echinoids and foraminiferaThe most abundant fossil is Ostrea pulaskensis Harris 1894which first appears in the Gulf Coastal Plain in the lowerDanian (Bryan and Jones 1989 Hansen et al 1993 Cope etal 2005) Dinoflagellates are scarce consisting of membersof the Areoligera group which are not ageminusdiagnostic Thusthe basal Hornerstown Formation is lower Danian based onthe presence of O pulaskensis although it is difficult to beany more precise than that

Iridium analysisWe analyzed 37 samples of sediment for iridium across theoutcrop in the Manasquan River Basin following the proceminusdure described in Schellenberg et al (2004) The base of thePinna Layer is marked by an enriched concentration of iridminusium which may correlate with the iridium anomaly first reminusported by Alvarez et al (1980) The maximum concentrationof iridium at two sites in the basin as reported in Landman etal (2007a) is 457 and 589 pgg (Fig 1) The iridium profileis asymmetric with an abrupt drop off above the contact and amore gradual decline below the contact A very similar patminustern has been reported from the same site by Miller et al(2010)

DiscussionEnvironment of depositionmdashThe mode of occurrence ofthe specimens in the Pinna Layer suggests an autochthonousassemblage that has undergone little or no timeminusaveraging(see Kidwell and Bosence 1991 for a fuller description ofsuch assemblages) Many of the bivalves are preserved in lifeposition Pinna laqueata is oriented vertically in the sediminusment similar to that of modern members of the genusCucullaea vulgaris which is semiminusinfaunal occurs in associminusations of up to 50 specimens with both valves commonly atminustached Echinoids also appear in aggregations of hundreds ofindividuals suggesting gregarious feeding behavior In addiminustion there are monospecific clusters of baculites and scaminusphites some of which consist of more than 30 adult speciminusmens which have been interpreted as reflecting postminusmating



Table 2 Fossils in the burrows of the Burrowed Unit comprising mateminusrial piped down from the Hornerstown Formation Monmouth CountyNew Jersey The authors of the species are listed in Landman et al(2007a table 1) Abbreviations R= potentially reworked from the PinnaLayer or an updip equivalent NR = nonminusreworked

Bivalvia Anomia spNR

Arca spNR

Cardium eufaulensis NR

Crassatella spNR

Cucullaea vulgaris NR R

Cyclorisma pumila R

Gryphaeostrea vomer NR

Ostrea pulaskensis NR

Pecten venustus R NR

Pecten argillensis NR

Pycnodonte spNR

Unicardium concentricum NR

Xylophagella irregularis NR

Gastropoda Bellifusus spR

Epitonium spR

Euspira sp R

Margaritella pumila NRR

Turritella sp R

Cephalopoda Discoscaphites iris R

Eubaculites latecarinatus R

Bryozoa Heteropora americana R

unidentified bryozoan NR

Echinodermata echinoid spines NR

Porifera Cliona spR

Arthropoda crab bits NRR

Annelida worm tubes NRR

Foraminifera NR

Dinoflagellata Areoligera senonensis species complexNRR

Areoligera sp indetNRR

Diphyes spNRR

Unidentifiable small fragments(Cordosphaeridium complex)NRR

or postminusspawning fatalities (Landman et al 2007a) Scaphitejaws are present both as isolated specimens and inside bodychambers All this evidence suggests rapid deposition withlittle or no postminusmortem transport The Pinna Layer may thusrepresent a relatively short interval of time ranging from tensto hundreds of years Based on estimates of the sea level atthe time Landman et al (2007a) inferred that the environminusment of deposition of the Pinna Layer was relatively shalminuslow with estimates of 20ndash30 m depth

The mode of occurrence of the specimens in the BurrowedUnit in contrast suggests a mixed death assemblage that hasbeen modified by hydraulic processes Almost all of the biminusvalves are disarticulated and not in life position The ammominusnites are fragmented pieces of larger specimens suggestingpostminusmortem transport and breakage None of the fossils occursin clusters The environment of deposition of the BurrowedUnit was probably similar to that of the Pinna Layer approximinusmately 20ndash30 m deep Although it is difficult to estimate therate of sediment deposition the presence of ammonite jawssuggests relatively rapid burial based on taphonomic experiminusments involving modern coleoid jaws (Kear et al 1995) Assuch the Burrowed Unit may represent a relatively short interminusval of time ranging from tens to hundreds of years or even less

The contact between the Burrowed Unit and the Hornersminustown Formation marks a hiatus coinciding with an extensiveperiod of reworking At ageminusequivalent sites in northeasternMonmouth County Landman et al (2004b) estimated that thishiatus may have lasted 100 000 years The environment of deminusposition of the Hornerstown Formation is inferred to be slightlydeeper than that of the Burrowed Unit or Pinna Layer as theresult of a transgression starting in the late Maastrichtian basedon an interpretation of the sequence stratigraphy of the UpperCretaceous of New Jersey (Cohen et al 2010)

The burrows in the Burrowed Unit were produced duringthe deposition of the Hornerstown Formation The burrowsextend through a thickness of approximately 20 cm The factthat they do not penetrate into the Pinna Layer suggests thatthis unit must have been indurated at that time However thesediment of the Burrowed Unit was apparently soft enoughto allow the burrows to penetrate into it but competentenough to maintain a sharp boundary between the sedimentand the burrows

TaphonomymdashThe fossils in the Pinna Layer are preservedas internal and external molds without any original shell Theinternal molds are usually composed of glauconitic mineralsMore rarely they are composed of sideritic clay which musthave hardened before the sediment was glauconitized thuspreserving its original texture All of the fossils in the PinnaLayer are considered to have formed during deposition ofthis layer

The fossils in the Burrowed Unit are preserved in thesame way as those in the Pinna Layer Most of the internalmolds are composed of glauconitic minerals whereas a miminusnority are composed of sideritic clay which matches the clayin the matrix We therefore conclude that these fossils also

formed during deposition of the surrounding sediment Simiminuslarly the ammonite aptychi were probably fossilized duringdeposition of the Burrowed Unit They are fragile and preminussumably would not have survived the process of reworking(for a discussion about the taphonomy of ammonite jaws seeWani et al 2005 and Wani 2007) Another argument againstreworking of the aptychi is the fact that jaws of Eubaculiteshave never previously been reported from the Pinna Layer orany other unit in North America

As noted above the Hornerstown Formation containsboth reworked and nonminusreworked fossils The nonminusreworkedfossils are pinkish brown in color probably representing diaminusgenetically altered shell The reworked fossils are composedof whitish sideritic clay surrounded by dark green glaucominusnitic pellets This clay is similar to that in the Pinna Layerand Burrowed Unit but is much lighter in color suggestingthat it was perhaps altered during the process of reworking

The reworked fossils in the Hornerstown Formation arealso piped down into the Burrowed Unit It is possible that thisis the origin of the two large clay pods containing hollow maminusterial in the Burrowed Unit Both of the pods are adjacent toburrows However they are not as light colored as the other reminusworked fossils and clasts in the Hornerstown Formation

The reworked material at the base of the HornerstownFormation was probably derived from winnowing and erominussion of the Pinna Layer at more updip sites during the earlyDanian transgression Because the fauna and lithology ofthe reworked fossils are identical to those in the PinnaLayer it seems unnecessary to invoke a ghost unit that is nolonger preserved Similarly it is unlikely that the source ofthe reworked material was the Burrowed Unit itself becausethis layer is depauperate For example the most commonlyreworked fossil in the basal Hornerstown Formation isCucullaea vulgaris This species is very abundant in thePinna Layer whereas it is virtually absent in the BurrowedUnit The Pinna Layer is still present along strike at a site 15km to the southwest (Ivanhoe Creek Fig 1 number 3)However in a more updip site 11 km to the northwest(Buckrsquos Pit Fig 1 number 2) the Burrowed Unit as well asthe Pinna Layer are absent (Cohen et al 2010) Based onour recent investigations at this site the Hornerstown Forminusmation lies directly on sediments representing the lowerpart of the upper Maastrichtian (calcareous nannofossilSubzone CC25c) This suggests that the source material forthe reworked fossils in the basal Hornerstown Formationwas probably from the Pinna Layer at more updip locations

Sequence of eventsmdashThe interpretation of the sequence ofevents represented by the Pinna Layer the Burrowed Unit andthe Hornerstown Formation depends on the significance andposition of the enriched concentration of iridium The iridumspike is very well defined and although the concentration isnot as high as that reported at some other CretaceousPaleominusgene boundary sections (Kiessling and Claeys 2002) includingthe Bass River core New Jersey (Olsson et al 1997) it is suffiminusciently above background level to suggest that this section reminus


cords deposition of iridium from the bolide impact The horiminuszon with enriched iridium marks the CretaceousPaleogeneboundary at the Global Stratotype Section and Point at El KefTunisia (Cowie et al 1989 Molina et al 2009)

The crucial question is whether the iridium concentrationin the Manasquan River Basin is in place thereby markingthe CretaceousPaleogene boundary (Fig 1) Landman et al(2007a) and Miller et al (2010) enumerated the evidence infavor of and against displacement of the iridium anomalyThis evidence involves the shape of the iridium profile thedistribution and kind of fossils and the presence or absenceof spherules shocked quartz and other platinum group eleminusments in comparison with other sites We present three posminussible scenarios of the sequence of events depending on theinterpretation of the original position of the iridium anomaly

(i) The iridium was originally deposited at the base of thePinna Layer The lack of any trace of iridium in the rest of thePinna Layer is consistent with this hypothesis For example atother sites where remobilization has been invoked secondarypeaks are still present at the original position of the iridium(eg Olsson et al 1997) In addition Bigolski et al (2010)have shown high concentrations of nickel and cobalt in theManasquan River Basin at the same horizon as the iridiumThey argued that the nickel and cobalt were delivered to thesite by Niminusrich bolide ejecta Such concentrations also appearat nearby sites in New Jersey where the iridium anomaly coinminuscides with the biostratigraphic markers usually interpreted asindicating the CretaceousPaleogene boundary (Denton et al2010)

If the iridium is in place then the Pinna community wasalready established at the moment of impact and may evenhave flourished in the immediate aftermath of the bolide imminuspact perhaps due to enhanced nutrient runoff from the contiminusnent (Kump 1991) The community would have persisted ashort interval of time perhaps tens to hundreds of years andmay have been buried by one or more pulses of mudminusrichsediment from overflowing rivers in the early Danian TheBurrowed Unit with its impoverished fauna may represent asubsequent interval perhaps reflecting a collapse in marineproductivity (Hsuuml and McKenzie 1985) that lasted tens tohundreds of years (Selpuacutelveda et al 2009) In summary theammonites in the Pinna Layer and in the Burrowed Unitwould have been shortminusterm survivors of the bolide impactand would have persisted into the Danian

(ii) The iridium was originally deposited at the top of thePinna Layer and was subsequently displaced downward Infavor of remobilization is the absence as yet of a specificfallout layer containing spherules or shocked quartz at thesame horizon as the iridium Remobilization has also beenpostulated based on comparisons with other sites In CretaminusceousPaleogene sections in Poland the iridium spike occurs10 cm below a clay layer that is interpreted as marking theboundary (Racki et al 2010) The authors attributed this toremobilization due to humic acidminusrich ground waters In theBass River Core in New Jersey the iridium anomaly occursat the base of a 6minuscmminusthick spherule layer (Olsson et al

1997) The authors also attributed this to remobilization dueto postminusdepositional diffusion Miller et al (2010) documinusmented additional sites in New Jersey where the iridiumanomaly coincides with the biostratigraphic markers usuallyinterpreted as indicating the boundary and therefore they arminusgued by extension that the iridium anomaly was displaceddownward in the Manasquan River Basin Indeed at mostsites around the world the iridium anomaly and the biominusstratigraphic markers usually interpreted as indicating theboundary coincide (eg the type section in Tunisia)

In this scenario the bolide impact would have caused thedestruction of the Pinna community If some animals werestill alive at the time they could have translated the iridiumspike downward via bioturbation Alternatively the spike mayhave subsequently migrated downward due to chemical reminusmobilization [see Guinasso and Schink (1975) and Rocchiaand Robin (1998) for a further discussion about the effects ofbioturbation and diffusion on the redistribution of iridium andother elements] The Burrowed Unit would have been deposminusited in the immediate aftermath of the impact still capturingsome of the same community but only in a very reduced andmodified state The presence of ammonite jaws in the Burminusrowed Unit would suggest that some ammonites survived thebolide impact although perhaps only momentarily

(iii) The iridium was originally deposited at the top of theBurrowed Unit and was subsequently displaced downwardby chemical remobilization through a thickness of 40 cmThis implies that the iridium anomaly and the biostratiminusgraphic markers were originally coincident In this scenariothe impact would have postminusdated the Pinna community butmight have contributed to the end of the much less diversecommunity in the Burrowed Unit The ammonites at least atthis site would not have survived the impact

In all three scenarios the nonminusreworked fossils in the basalHornerstown Formation probably represent the postminusimpactcommunity although it is difficult to determine how muchtime is missing at the contact between the Burrowed Unit andthe Hornerstown Formation The fauna consists of only 15species including several Cretaceous holdovers (eg Margaminusritella pumila and Pecten venustus) and is dominated by thesmall suspensionminusfeeding oyster Ostrea pulaskensis The preminusdominance of this species is reminiscent of the high abunminusdance of ferns following the collapse of the angiosperms inthe terrestrial record of the CretaceousPaleogene boundary(Vajda et al 2001)

ConclusionsThis report emphasizes the importance of the Burrowed Unitin trying to resolve the events in the Manasquan River BasinNew Jersey at the end of the Cretaceous Of the scenariosdescribed above Scenario 1 does not involve any remobiliminuszation of the iridium It implies that the Pinna communitypersisted and perhaps even thrived in the immediate afterminusmath of the impact followed by the more impoverished comminus



munity in the Burrowed Unit Scenario 2 involves remobiliminuszation of the iridium through a thickness of 20 cm It impliesthat the Pinna community was destroyed by the impact andthe ensuing environmental maelstrom and was replaced bythe depauperate community in the Burrowed Unit Scenario3 involves remobilization of the iridium through a thicknessof 40 cm It implies that the ammonites perished at approximinusmately the same time as the bolide impact In Scenarios 1 or2 the ammonites would have survived the impact at this sitefor a brief interval of time lasting from a few days to hunminusdreds of years Choosing among these three scenarios reminusquires additional information about other geochemical markminusers in the Manasquan River Basin (spherules shocked quartzgrains) and comparison with KPg sites elsewhere on the Atminuslantic and Gulf Coastal Plains

AcknowledgementsWe thank Danielle Jeffrey (Brooklyn College New York USA) whohelped search for and prepare the fossils in the Burrowed Unit andRalph Johnson (MAPS USA) who assisted at the beginning of thisproject During the course of this research we benefitted from discusminussions with Marcin Machalski (Instytut Paleobiologii PAN WarsawPoland) Claus Heinberg (Roskilde Universitetscenter Roskilde Denminusmark) John WM Jagt (Natuurhistorisch Museum Maastricht Maasminustricht The Netherlands) and J Kirk Cochran (Stony Brook UniversityNew York USA) with whom we collaborated on a project on ammonitesurvival in Denmark An early version of this paper was reviewed byPeter J Harries (University of South Florida Tampa USA) and MarcinMachalski who made many helpful suggestions that improved thequality of the final manuscript

ReferencesAlvarez L Alvarez W Asaro F and Michel HV 1980 Extraterrestrial

cause for the CretaceousndashTertiary extinction Science 208 1095ndash1108Bigolski JN Ebel DS Hsieh CminusT Landman NH and Bosenberg

JS 2010 Ni and Co in pyrite framboids from Agony Creek KPgboundary in New Jersey Coastal Plain Geological Society of AmericaAbstracts with Programs 42 (5) 305

Brunnschweiler RO1966 Upper Cretaceous ammonites from the CarnarvonBasin of Western Australia I The heteromorph Lytoceratina Bureau ofMineral Resources Geology and Geophysics Bulletin 58 1ndash58

Bryan JR and Jones DS 1989 Fabric of the CretaceousndashTertiary marinemacrofaunal transition at Braggs Alabama Palaeogeography Palaeominusclimatology Palaeoecology 69 279ndash301

Cohen A Garb MP Klofak SM and Landman NH 2010 The CretaminusceousndashTertiary transition A unique paleoenvironmental perspective onthe New Jersey Atlantic Coastal Plain Geological Society of AmericaAbstracts with Programs 42 (5) 256

Collignon M 1952 Ammonites neacuteocretaceacutees du Menabe (Madagascar) IILes Pachydiscidae Travaux du Bureau Geacuteologique de Madagascar 411ndash114

Conrad TA 1858 Observations on a group of Cretaceous fossil shellsfound in Tippah County Mississippi with descriptions of fiftyminussix newspecies Journal of the Academy of Natural Sciences of PhiladelphiaSecond Series 3 (4) 323ndash336

Conrad TA 1869 Observations on the genus Astarte with descriptions ofthree other genera of Crassatellidae American Journal of Conchology5 46ndash48

Cowie JW Ziegler W and Remane J 1989 Stratigraphic Commissionaccelerates progress 1984 to 1989 Episodes 12 (2) 79ndash83

Cope KH Utgaard JE Masters JM and Feldmann RM 2005 Thefauna of the Clayton Formation (Paleocene Danian) of southern Illiminusnois a case of KP survivorship and Danian recovery Bulletin of theMizunami Fossil Museum 32 97ndash108

Denton DS Hsieh CminusT Landman NH and Bosenberg JS 2010 Niand Co in pyrites mark the KT boundary in the Crosswicks Creek Baminussin Monmouth County New Jersey USA Geological Society ofAmerica Abstracts with Programs 42 (5) 305

Edwards LE Gohn GS SelfminusTrail JM Prowell DC Bybell LMBardot LP Firth JV Huber BT Frederiksen NO and MacLeodKG 1999 Physical stratigraphy paleontology and magnetostratiminusgraphy of the USGSminusSantee Coastal Reserve core (CHNminus803) Charleminusston County South Carolina United States Geological Survey OpenminusFile Report 99minus0308minusA 1ndash36

Eisenack A 1954 Mikrofossilien aus Phosphoriten des samlaumlndischen Unterminusoligozaumlns und uumlber Einheitlichkeit der Hystrichosphaerideen Palaeontominusgraphica A 105 49ndash95

Eisenack A and Gocht H 1960 Neue Namen fuumlr einige Hystrichosphaumlrender Bernsteinformation Ostpreussens Neues Jahrbuch fuumlr Geologieund Palaumlontologie Monatshefte 1960 (11) 511ndash518

Gabb WM 1859 Article IX Descriptions of some new species of Cretaminusceous fossils Journal of the Academy of Natural Sciences of Philadelminusphia Second Series 3 (4) 299ndash305

Gallagher WB 1993 The CretaceousTertiary mass extinction event in thenorthern Atlantic Coastal Plain The Mosasaur 5 75ndash155

Gocht H 1970 DinoflagellatenminusZysten aus einem Geschiebefeuerstein undihren Erhaltungszustand Neues Jahrbuch fuumlr Geologie und Palaumlontominuslogie Monatshefte 1970 (3) 129ndash140

Guinasso NL Jr and Schink DR 1975 Quantitative estimates of biologminusical mixing rates in abyssal sediments Journal of Geophysical Reminussearch 80 (21) 3023ndash3043

Hansen TA Upshaw III B Kauffman EG and Gose W 1993 Patternsof molluscan extinction and recovery across the CretaceousndashTertiaryboundary in east Texas report on new outcrops Cretaceous Research14 685ndash706

Harris GD 1894 The Tertiary geology of southern Arkansas ArkansasGeological Survey Annual Report for 1892 2 1ndash207

Hsuuml KJ and McKenzie JA 1985 A ldquoStrangelove Oceanrdquo in the earliestTertiary In ET Sundquist and W Broecker (eds) American Geominusphysical Union Monograph 32 487ndash492

Jagt JWM Smit J and Schulp AS 2003 Early Paleocene ammonitesand other molluscan taxa from the AngerpoortminusCurfs quarry (Geulhemsouthern Limburg the Netherlands) In MA Lamolda (ed) BioeventsTheir Stratigraphical Records Patterns and Causes Caravaca 3rdndash8th

June 2003 113 Ayuntamiento de Caravaca de la Cruz CaravacaKear AJ Briggs DEG and Donovan DT 1995 Decay and fossilizaminus

tion of nonminusmineralized tissue in coleoid cephalopods Palaeontology38 105ndash131

Kennedy WJ and Cobban WA 2000 Maastrichtian (Late Cretaceous)ammonites from the Owl Creek Formation in northeastern MississippiUSA Acta Geologica Polonica 50 175ndash190

Kidwell SM and DWJ Bosence 1991 Taphonomy and timeminusaveragingof marine shelly faunas In PA Allison and DEG Briggs (eds)Taphonomy Releasing the Data Locked in the Fossil Record 115ndash209Plenum New York

Kiessling W and Claeys P 2002 A geographic database approach to the KTBoundary In E Buffetaut and C Koeberl (eds) Geological and Biologiminuscal Effects of Impact Events 83ndash140 Springer Verlag New York

Kump LR 1991 Interpreting carbonminusisotope excursions Strangeloveoceans Geology 19 299ndash302

Landman NH Johnson RO and Edwards LE 2004a Cephalopods fromthe CretaceousTertiary boundary interval on the Atlantic Coastal Plainwith a description of the highest ammonite zones in North America Part 1Maryland and North Carolina American Museum Novitates 3454 1ndash64

Landman NH Johnson RO and Edwards LE 2004b Cephalopodsfrom the CretaceousTertiary boundary interval on the Atlantic Coastal


Plain with a description of the highest ammonite zones in North Amerminusica Part 2 Northeastern Monmouth County New Jersey Bulletin of theAmerican Museum of Natural History 287 1ndash107

Landman NH Johnson RO Garb MP Edwards LE and Kyte FT2007a Cephalopods from the CretaceousTertiary boundary interval onthe Atlantic Coastal Plain with a description of the highest ammonitezones in North America Part III Manasquan River Basin MonmouthCounty New Jersey Bulletin of the American Museum of Natural Hisminustory 303 1ndash122

Landman NH Johnson RO Garb MP Edwards LE and Kyte FT2010a Ammonites from the CretaceousTertiary boundary New JerseyUSA In K Tanabe Y Shigeta T Sasaki and H Hirano (eds) CephalominuspodsmdashPresent and Past 287ndash295 Tokai University Press Tokyo

Landman NH Kennedy WJ Cobban WA and Larson NL 2010bScaphites of the ldquonodosus grouprdquo from the Upper Cretaceous (Campaminusnian) of the Western Interior of North America American Museum ofNatural History Bulletin 342 1ndash242

Landman NH Larson NL and Cobban WA 2007b Jaws and radula ofBaculites from the Upper Cretaceous (Campanian) of North AmericaIn NH Landman RA Davis and RH Mapes (eds) CephalopodsPresent and Past New Insights and Fresh Perspectives 257ndash298Springer Verlag New York

LejeuneminusCarpentier M 1942 Lrsquoeacutetude microscopique des silex Peacuteridiniensnouveaux ou peu connnus (Dixiegraveme note) Annales de la Socieacuteteacutegeacuteologique de Belgique 65 B181ndashB192

Lentin JK and Williams GL 1973 Fossil dinoflagellates index to generaand species Geological Survey of Canada Paper 73minus42 1ndash176

Machalski M and Heinberg C 2005 Evidence for ammonite survival intothe Danian (Paleogene) from the Cerithium Limestone at Stevns KlintDenmark Bulletin of the Geological Society of Denmark 52 97ndash111

Machalski M Jagt JWM Heinberg C Landman NH and HaringkanssonE 2009 Dańskie amonity ndash obecny stan wiedzy i perspektywy badańPrzegląd Geologiczny 57 486ndash493

Miller KG Sugarman PJ Browning JV Kominz MA Olsson RKFeigenson MD and Hernaacutendez JC 2004 Upper Cretaceous seminusquences and seaminuslevel history New Jersey Coastal Plain GeologicalSociety of American Bulletin 116 (34) 368ndash393

Miller KG Sherrell RM Browning JV Field MP Gallagher WOlsson RK Sugarman PJ Tuorto S and Wahyudi H 2010 Relaminustionship between mass extinction and iridium across the CretaceousndashPaleogene boundary in New Jersey Geology 38 867ndash870

Minard JP Owens P Sohl NF Gill HE and Mello JF 1969 CretaminusceousndashTertiary boundary in New Jersey Delaware and eastern Maryminusland United States Geological Survey Bulletin 1274minusH 1ndash33

Molina E Alegret L Arenillas I Arz JA Gallala N GrajalesminusNishimura JM MurillominusMuntildeetoacuten G and ZaghbibminusTurki D 2009The Global Boundary Stratotype Section and Point for the base of theDanian Stage (Paleocene Paleogene ldquoTertiaryrdquo Cenozoic) auxiliarysections and correlation Episodes 32 84ndash95

Morton SG 1828 Description of the fossil shells which characterize theAtlantic Secondary Formation of New Jersey and Delaware includingfour new species Journal of the Academy of Natural Sciences of Philaminusdelphia 6 73ndash76

Morton SG 1830 Synopsis of the organic remains of the Ferruginous SandFormation of the United States with geographical remarks AmericanJournal of Science and Arts 17 274ndash295

Morton SG 1833 Article XminusSupplement to the ldquoSynopsis of the organicremains of the Ferruginous Sand Formation of the United Statesrdquo conminustained in Vols XVII and XVIII of this journal American Journal of Sciminusence and Arts 23 288ndash294

Morton SG 1834 Synopsis of the organic remains of the Cretaceousgroup of the United States Illustrated by nineteen plates to which isadded an appendix containing a tabular view of the Tertiary fossils hithminuserto discovered in North America 88 pp Key and Biddle Philadephia

Olsson RK Miller KG Browning JV Habib D and Sugarman PJ1997 Ejecta layer at the CretaceousndashTertiary boundary Bass River NewJersey (Ocean Drilling Program Leg 174AX) Geology 25 759ndash762

Owens JP Sugarman PJ Sohl NF Parker RA Houghton HF

Volkert RA Drake AA Jr and Orndorff RC 1998 Bedrock geominuslogic map of central and southern New Jersey United States GeologicalSurvey Miscellaneous Investigations Series Map Iminus2540minusB

Racki G Machalski M Koeberl C and Harasimiuk M 2010 The weathminuseringminusmodified iridium record of a new CretaceousndashPalaeogene site atLechoacutewka near Chełm SE Poland and its palaeobiologic impricationsActa Palaeontologica Polonica 56 205ndash215

Richards HG 1962 Appendix C New Cretaceous invertebrate fossils fromtest borings in New Jersey In CW Cooke HF Garner BF Howell JAJeletzky AK Miller HWMiller Jr RC Ramsdell HG Richards JBReeside Jr HB Roberts and JW Wells (eds) The Cretaceous Fossilsof New Jersey New Jersey Department of Conservation and EconomicDevelopment Bulletin 61 (2) 199ndash207

Rocchia R and Robin E 1998 Lrsquoiridium agrave la limite CreacutetaceacutendashTertiaire dusite drsquoEl Kef Tunisie Bulletin de la Socieacuteteacute geacuteologique de France 169(4) 515ndash526

Schellenberg SA Brinkhuis H Stickley CF Fuller M Kyte FT andWilliams GL 2004 The CretaceousPaleogene transition on the EastTasman Plateau Southwestern Pacific In N Exon JP Kennett and MMalone (eds) The Cenozoic Southern Ocean Tectonics Sedimentationand Climate Change Between Australia and Antarctica GeophysicalMonograph Series 151 93ndash112

Schioslashler P and Wilson GJ 1993 Maastrichtian dinoflagellate zonation inthe Dan Field Danish North Sea Review of Palaeobotany and Palynology78 321ndash351

Schulte P Alegret L Arenillas I Arz JA Barton PJ Bown PRBralower TJ Christeson GL Claeys P Cockell CS Collins GSDeutsch A Goldin TJ Goto K GrajalesminusNishimura JM GrieveRAF Gulick SPS Johnson KR Kiessling W Koeberl K KringDA MacLeod KG Matsui T Melosh J Montanari A MorganJV Neal CR Nichols DJ Norris RD Pierazzo E Ravizza GRebolledominusVieyra M Reimold WU Robin E Salge T Speijer RPSweet AR UrrutiaminusFucugauchi J Vajda V Whalen MT andWillumsen PS 2010 The Chicxulub asteroid impact and mass extinctionat the CretaceousndashPaleogene Boundary Science 327 1214ndash1218

Selpuacutelveda J Wendler JE Summons RE and Hinrichs KminusU 2009Rapid resurgence of marine productivity after the CretaceousndashPaleominusgene mass extinction Science 326 129ndash132

Smit J and Brinkhuis H 1996 The Geulhemmerberg CretaceousTertiaryboundary section (Maastrichtian type area SE Netherlands) summary ofresults and a scenario of events Geologie en Mijnbouw 75 283ndash293

Stephenson LW 1941 The larger invertebrates of the Navarro Group ofTexas (exclusive of corals and crustaceans and exclusive of the fauna ofthe Escondido Formation) University of Texas Bulletin 4101 1ndash641

Stephenson LW 1955 Owl Creek (Upper Creatceous) fossils from Crowminusleyrsquos Ridge southeastern Missouri United States Geological Survey Prominusfessional Paper 274 97ndash140

Tuomey M 1856 Description of some new fossils from the Cretaceousrocks of the southern States Proceedings of the Academy of NaturalSciences of Philadelphia 7 (for 1854) 167ndash172

Vajda V Raine JI and Hollis CJ 2001 Indication of global deforestaminustion at the CretaceousndashTertiary boundary by New Zealand fern spikeScience 294 1700ndash1702

Wani R 2007 How to recognize in situ fossil cephalopods evidence fromexperiments with modern Nautilus Lethaia 40 305ndash311

Wani R Kase T Shigeta Y and De Ocampo R 2005 New look atammonoid taphonomy based on field experiments with modern chamminusbered nautilus Geology 33 849ndash852

Wetzel O 1933 Die in organischer Substanz erhaltenen Mikrofossilien desbaltischen KreideminusFeuersteins mit einem sedimentminuspetrographischenund stratigraphischen Anhang Palaeontographica A 78 1ndash110

Whitfield RP 1886 Brachiopoda and Lamellibranchiata of the RaritanClays and Greensand Marls of New Jersey US Geological SurveyMonograph Volume 9 (= New Jersey Geological Survey Paleontominuslogical Series Volume 1) 1ndash348

Whitfield RP 1892 Gasteropoda and Cephalopoda of the Raritan Claysand Greensand Marls of New Jersey United States Geological SurveyMonograph 18 1ndash402



Landman et al (2007a 2010a) investigated outcrops inMonmouth County New Jersey that contain ammonites anddinoflagellates associated with an iridium anomaly These fosminussils are traditionally assigned to the uppermost Maastrichtianbut appear above the iridium anomaly suggesting that theymay actually be Danian The fossils occur in two layers thelower layer known as the Pinna Layer is very fossiliferousand has been thoroughly documented by Landman et al(2007a 2010a) The upper layer known as the Burrowed Unitcontains a depauperate assemblage of ammonites and dinominusflagellates and has received much less attention In this paper

we focus on the ammonites in this unit to determine if theywere fossilized at the time of deposition of the surrounding sedminusiment having lived andor died during this time interval or ifthey were reworked from older deposits The ultimate explanaminustion of the sequence of events at this site depends however onwhether the iridium anomaly represents the record of the bolideimpact and if so whether it is in place or has migrated downminusward (Landman et al 2007a Miller et al 2010)

Institutional abbreviationsmdashAMNH American Museum ofNatural History New York USA MAPS Monmouth Amaminusteur Paleontological Society Long Branch New Jersey


Fig 1 Stratigraphic section in the Manasquan River Basin Monmouth County New Jersey A The top of the Tinton Formation consists of the Pinna Layeroverlain by the Burrowed Unit which is overlain in turn by the Hornerstown Formation An enriched concentration of iridium occurs at the base of thePinna Layer (indicated by the stars) The position of the CretaceousPaleogene boundary in this figure is based on the assumption that the enriched concenminustration of iridium is in place B Iridium profile from two sites (represented by the solid and dashed lines) in the Manasquan River Basin (Landman et al2007a) C Map of part of New Jersey showing localities mentioned in the text 1 Manasquan River Basin 2 Buckrsquos Pit 3 Ivanhoe Creek

































B

E

M

C

KG H

Q

I J

N O P

R S T U V

3AA1 2AD1 2D 3D F1 F2

L1

3L

2L




C

A



5 mm10 mm 10 mm

D1 D2

E1 E2








A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR



































































































































B

E

M

C

KG H

Q

I J

N O P

R S T U V

3AA1 2AD1 2D 3D F1 F2

L1

3L

2L




C

A



5 mm10 mm 10 mm

D1 D2

E1 E2








A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR

























































































































B

E

M

C

KG H

Q

I J

N O P

R S T U V

3AA1 2AD1 2D 3D F1 F2

L1

3L

2L




C

A



5 mm10 mm 10 mm

D1 D2

E1 E2








A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR
























































































































B

E

M

C

KG H

Q

I J

N O P

R S T U V

3AA1 2AD1 2D 3D F1 F2

L1

3L

2L




C

A



5 mm10 mm 10 mm

D1 D2

E1 E2








A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR




































































































B

E

M

C

KG H

Q

I J

N O P

R S T U V

3AA1 2AD1 2D 3D F1 F2

L1

3L

2L




C

A



5 mm10 mm 10 mm

D1 D2

E1 E2








A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR





































































































C

A



5 mm10 mm 10 mm

D1 D2

E1 E2








A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR








































































































A B C

3 mm

100 μm

3 mm 3 mm

3 mm

D1 D2












Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR













































































































Arca spNR


Crassatella spNR


Cyclorisma pumila R





Pycnodonte spNR




Epitonium spR

Euspira sp R


Turritella sp R






Porifera Cliona spR



Foraminifera NR



Diphyes spNRR









































































































































































































































































































































































































Documents

Short−term survival of ammonites in New Jersey after the ... · Ammonites include Pachydiscus (Neodesmoceras) mokotibensis, Sphenodiscus lobatus , Eubaculites carinatus , E. latecarinatus