Sea-level related resedimentation processes on the northern slope of Little Bahama Bank (Middle...

Sea-level related resedimentation processes on the northernslope of Little Bahama Bank (Middle Pleistocene to Holocene)

HENDRIK LANTZSCH,*1 SVEN ROTH*�2, JOHN J. G. REIJMER*�3 and HANNO KINKEL�*IFM-Geomar, Leibniz-Institut fur Meereswissenschaften, Dienstgebaude Ostufer, Wischhofstr. 1-3,24148 Kiel, Germany (E-mail: [email protected])�Centre de Sedimentologie-Paleontologie, Universite de Provence (Aix-Marseille I), 3, place Victor Hugo,13331 Marseille Cedex 3, France�Institut fur Geowissenschaften, Christian-Albrechts-Universitat zu Kiel, Ludewig-Meyn-Str. 10, 24118Kiel, Germany

ABSTRACT

Middle Pleistocene to Holocene sediment variations observed in a 26 metre

long core taken during a cruise of the RV Marion Dufresne are presented. Core

MD992202 was retrieved from the northern slope of Little Bahama Bank and

provides an excellent example for sedimentation processes in a mid-slope

depositional environment. The sediment composition indicates sea-level

related deposition processes for the past 375 000 years (marine isotope

stages 1 to 11). The sediments consist of: (i) periplatform ooze (fine-grained

particles of shallow-water and pelagic origin) with moderate variations in

carbonate content, carbonate mineralogy and grain-size; and (ii) coarser

intervals with cemented debris consisting of massive, poorly sorted, mud-

supported or clast-supported deposits with an increased high-magnesium

calcite content. During interglacial stages (marine isotope stages 1, 5, 7, 9 and

11) periplatform oozes (i) are characterized by higher aragonite contents, finer

grain-size and higher organic contents, whereas during glacial stages (marine

isotope stages 2 to 4, 6, 8 and 10), increased low-magnesium and high-

magnesium calcite values, coarser grain-size and lower organic contents are

recorded. These glacial to interglacial differences in mineralogy, grain-size

distribution and organic content clearly show the impact of climatically

controlled sea-level fluctuations on the sedimentation patterns of the northern

slope of Little Bahama Bank. The coarser deposits (ii) occur mainly at the

transitions from glacial to interglacial and interglacial to glacial stages, and are

interpreted as redeposition events, indicating a direct link between sediment

properties (changes in mineralogy, grain-size distribution, variations in

organic contents) and sea-level fluctuations. Changes in hydrostatic pressure

and the wave base position during sea-level changes are proposed to have

triggered these large-scale sediment redepositions.

Keywords Bahamas, carbonate slopes, Caribbean, debris flows, Holocene,Pleistocene.

1Present address: Fachbereich 05, Geowissenschaften, Fachgebiet Sedimentologie, Palaozeanographie, UniversitatBremen, P.O. Box 330 440, 28334 Bremen, Germany.2Present address: Numerical Rocks AS, Stiklestadveien 1, 7041 Trondheim, Norway.3Present address: Faculty of Earth and Life Sciences (FALW), Department of Sedimentology and Marine Geology,Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.

Sedimentology (2007) 54, 1307–1322 doi: 10.1111/j.1365-3091.2007.00882.x

� 2007 The Authors. Journal compilation � 2007 International Association of Sedimentologists 1307

INTRODUCTION

Recent studies have shown that redepositionprocesses on carbonate slopes are either relatedto sea-level fall or to sea-level rise in leeward andwindward settings (Hilbrecht, 1989; Grammeret al., 1993a). The processes triggering redeposi-tion and the timing are still a matter of debate.The tectonically stable Bahamas are very well-suited to study the timing and processes ofredeposition events related to sea-level fluctua-tions.

Little Bahama Bank (LBB) is the second largestand northernmost carbonate platform of theBahamian Archipelago (Fig. 1). The top of thenorth-western corner of LBB is generally flat andrarely exceeds a water depth of 6 m (Williams,1985). Sediment core MD992202 was recoveredfrom the northern slope of LBB from a waterdepth of 460 m (27�34Æ45¢ N, 78�57Æ93¢ W; Fig. 1).This slope site lies within a windward setting andis characterized by an accretionary slope type,consisting of a relatively steep (4�) upper slopebetween water depths of 200 and 900 m withnumerous gullies and a more gentle (1� to 2�)lower slope below 900 m (Hine & Neumann,1977; Schlager & Ginsburg, 1981; Mullins et al.,1984; Harwood & Towers, 1988). Wind frequencyand wave energy flux for the northern slope of

LBB are displayed in Fig. 2. The region fromwhich the core was retrieved is characterized byprevailing winds from the east, north-east andnorth (U.S. Naval Service Weather Command,1974, 1975 in Hine & Neumann, 1977) and by adominance of southerly wave energy flux.

This study may provide a model for sedimenta-tion processes on fossil carbonate platformslopes, where an exact timing of redepositionevents remains problematic because of temporaluncertainties. The objective of this study was tocharacterize sedimentation patterns on carbonateslopes through: (i) examination of variations inthe sediment composition (mineralogy, grain-sizeand stable oxygen isotope values of carbonateslope sediments); (ii) determining the timing ofthe compositional changes and to evaluate theirrelation to sea-level fluctuations; and (iii) charac-terizing the response of the overall carbonateslope system to sea-level changes and glacial/interglacial stages.

Fig. 1. Core position of MD992202. Arrows displaycurrent directions of upper 50 m surface layer (afterLeaman et al., 1995). Platform edges are indicated by200 m isobath. TOTO, Tongue of the Ocean; NWPC,Northwest Providence Channel; NEPC, NortheastProvidence Channel (modified from Roth & Reijmer,2004).

Fig. 2. Wind frequency (%) and wave energy flux(gms)3) for the Little Bahama Bank area. Data for windfrequency diagrams are from Miami Summary ofSynoptic Meteorological Observations (SSMO) andGrand Bahama SSMO and represent observations takenover a 40 year period in areas shown on inset map (U.S.Naval Weather Service Command, 1974, 1975 in Hine &Neumann, 1977). White arrows indicate total normalcomponent of wave-energy flux affecting bank–marginzone. Easterly and northerly facing margins are wind-ward, high-energy zones; westerly facing marginsare leeward and lower energy zones (modified fromHine & Neumann, 1977; satellite image from http://www.visibleearth.nasa.gov).

1308 H. Lantzsch et al.

� 2007 The Authors. Journal compilation � 2007 International Association of Sedimentologists, Sedimentology, 54, 1307–1322

PALAEOCEANOGRAPHIC SETTING

Two major input sources are known for sedimentsdeposited close to carbonate platforms: the shal-low platform itself and the open ocean. The majorpart of the sediments occurs as clay-sized ara-gonite needles, which are transported off-bank(Neumann & Land, 1975). High-magnesium cal-cite (HMC) may occur as cements or in the form ofneritic red algae and skeletal fragments of benthicforaminifera. Low-magnesium calcite (LMC) is ofplanktonic origin and is principally derived fromcoccolithophorids and planktonic foraminifera(Schlager & James, 1978). Schlager & James(1978) established the term ‘periplatform ooze’for this mixture of shallow-water carbonate mudand planktonic input. Variations between shal-low-water and pelagic input in periplatformsediments reflect changes in the depositionalconditions on the shallow-water platform. The‘highstand shedding’ model (Droxler & Schlager,1985; Reijmer et al., 1988; Schlager et al., 1994) isnow widely accepted for flat-topped carbonateplatforms to explain cyclic variations in thearagonite content in the deep-water realm adja-cent to carbonate platforms. During highstands,the platform top is flooded, enlarging the aragon-ite sediment production area, whereas duringlowstands the top is exposed, limiting the pro-duction area and the export of carbonate sedi-ments to deeper waters (Schlager et al., 1994;Dravis, 1996).

The vast quantity of excess bank-top aragoniteproduction and the limited storage volume in theshallow-water realm provide large volumes ofsediment available for off-bank export (Neumann& Land, 1975; Mullins et al., 1984; Roth &Reijmer, 2004). Off-bank transport of coarse-grained material occurs mainly during the pas-sage of storms along the leeward, open margin ofthe LBB (Hine et al., 1981). Tidal currents andnormal wave action cause only minor sandmovement, but relatively weak currents are ableto winnow fine-grained shallow-water sedimentand transport it to the slope (Hine et al., 1981).Off-bank sediment transport of fine-grained ara-gonite is forced by tide-driven and wind-drivenadvection and by ‘density cascading’ (Wilson &Roberts, 1995). The ‘density cascading’ modelsuggests that fine-grained sediment is entrainedby high-density waters and transported to theadjacent ocean. These hyperpycnal waters are theproduct of air–sea interactions, i.e. intense heatand moisture flux from the warm sea water intocold, dry continental air during the passing of

winter cold fronts and evaporation because ofsolar heating (Wilson & Roberts, 1995). Oncetransported off-bank, the sediments are trans-ported downslope mainly by turbidity currentsand debris flows (Mullins et al., 1984).

MATERIALS AND METHODS

Coring and sampling

In July 1999, core MD992202 was retrieved fromthe northern slope of the LBB (27�34Æ45¢ N,78�57Æ93¢ W; Fig. 1). The 26 m long sedimentcore was recovered from a 460 m water depthby the Calypso Giant Piston Coring Systemonboard RV Marion Dufresne. The core wassampled after visual core description and colourspectrophotometry. All depth values are repor-ted in centimetres below sediment surface. Inorder to obtain high-resolution data, a samplinginterval of 2 cm was chosen for the upper partof the core (0 to 510 cm). Throughout the lowerpart (510 to 2594 cm), an interval of 20 cm wasselected to obtain an overview of the long-termsedimentation patterns of core MD992202. Asubset of samples for X-ray diffraction (XRD)and Dumas combustion analysis were freeze-dried ()25 �C) and carefully ground by hand.Samples for grain-size analysis were weighedbefore and after freeze-drying to obtain thephysical properties of the sediment, such aswater content and dry density, which is neededfor the estimation of mass accumulation rates(MAR).

Radiocarbon measurements

To construct an age model for core MD992202, sixaccelerator mass spectrometry (AMS) 14C-meas-urements of the planktonic foraminifer Globigeri-noides sacculifer were performed at the LeibnizLaboratory for Age Determinations (Christian-Albrechts-University, Kiel, Germany). Thesamples were cleaned with 15% H2O2 in anultrasonic bath to remove dust, detrital carbonateand organic matter; following this procedure,they were treated with phosphoric acid (100%)at 90 �C. Using Fe powder as a catalyst, theevolving CO2 was reduced to elemental carbonand the resulting carbon–iron mixture waspressed in an aluminium holder.

The conventional 14C age was calculated afterStuiver & Polach (1977) including a correction forisotope fractionation. Error ranges of the derived

Resedimentation processes on carbonate slopes 1309


data comprise numerical statistics, stability of theAMS device and uncertainty of the subtractedzero effect. All ages are reported as uncalibrated14C ages.

Biostratigraphy

In order to improve the age model in coreMD992202 a number of samples were analysedfor calcareous nannofossil biostratigraphy. Sam-ples were prepared for scanning electron micro-scope (SEM) analysis using a modified version ofthe filtration method (Andruleit, 1996). A smallquantity (0Æ01 g) of sediment was homogenizedusing ultrasonification and filtered onto a poly-carbonate filter (pore size 0Æ4 lm) to ensure ahomogenous specimen distribution. A smallpiece of the filter was cut out and mounted onSEM stub, which was subsequently sputteredwith Au/Pd for SEM analysis. The filter wasscreened for the qualitative abundance of relevantMiddle Pleistocene to Holocene stratigraphicmarker species.

The Late Middle Pleistocene to Holocene nan-nofossil biostratigraphy is based on a few reliableevents, which have good time control based onastronomical tuned time series (Raffi et al., 2006).For the Middle Pleistocene to Holocene thefollowing biohorizons are relevant:

• highest occurrence (HO) of Pseudoemilianialacunosa [436 to 467 ka, marine isotope stages(MIS 12)];

• lowest occurrence (LO) of Emiliania huxleyi(265 to 291 ka, MIS 8);

• dominance interval of E. huxleyi (63 to 82 ka,MIS 4/5).

In addition, the Middle Pleistocene to Holocenecan be further subdivided by evolutionary chan-ges among coccolithophorids belonging to thegenus Gephyrocapsa. The most obvious intervalis the global acme of Gephyrocapsa caribbeanicain the Mid-Pleistocene (580 to 260 ka), which isreported by several authors (Bollmann et al.,1998; Baumann & Freitag, 2004).

Stable oxygen isotope analysis

Stable oxygen isotope ratios were measured witha Thermo Finnigan MAT Deltaplus Advantagemass spectrometer system (Thermo ElectronCorporation, Waltham, MA, USA) at the IFM-GEOMAR (Kiel, Germany). The planktonicforaminifer Globigerinoides ruber (white) wasselected for isotope analysis because G. ruber

represents the conditions in the upper surfacewater and stable oxygen isotope values of G. ruberhave been shown to correlate well with the stableoxygen isotope values of ice cores (Droxler et al.,1983; Boardman et al., 1986). Hand-picked sam-ples of G. ruber (white; 10 specimens) from thesize fraction 355 to 425 lm were floated with Hegas and treated with 100% H3PO4. The generatedCO2 was then measured by using a mass spectro-meter. The standard deviation of the measure-ments amounts to 0Æ07&. A conversion to theinternational Vienna Peedee Belemnite (V-PDB)scale was performed using the standard NBS19.All values are reported in parts per thousandagainst the V-PDB standard.

Foraminifera build up their calcite shells as afunction of water temperature and oxygen isotopecomposition of the ambient sea water. Dependingon the global ice volume, the measured ratio of18O to 16O (d18O) in the shells shows high valuesduring glacial phases (corresponding to sea-levellowstands) and low values during interglacialstages (corresponding to highstands in sea-level).Therefore, the d18O record of planktonic fora-minifera can be used for a climate–stratigraphiccorrelation to construct an age model. Glacial andinterglacial stages were classified in marine iso-tope stages (MIS), following the definition ofShackleton & Opdyke (1973), based on thepioneering work of Emiliani (1955), where oddnumbers generally represent interglacial stagesand glacial stages are labelled with even numbers.MIS 1 represents the Holocene and MIS 5 the lastfull interglacial.

Carbonate content, organic carbon andinsoluble residue

Total carbon (TC) and total organic carbon(TOC) were measured by Dumas combustionwith a C-200 Leco furnace (LECO InstrumenteGmbH, Monchengladbach, Germany) at IFM-GEOMAR (Kiel, Germany). The sample andaccelerator material were placed in a ceramiccrucible and combusted in an induction fur-nace. The CO2 produced was measured in theinfrared cell of the Leco furnace. The analysedTOC was then subtracted from TC to obtain thecarbonate carbon (wt%) present in the samples.In order to calculate the correct carbonatecontent (wt%), the exact ratio of Ca and Mgincorporated in the HMC has to be known. TheMg content of HMC was calculated from thed-values of the individual HMC peaks obtainedthrough XRD (see the section Mineralogy). The



Ca/Mg ratios within the HMC enable the calcu-lation of the atomic weight, which is multipliedwith the percentage of carbonate carbon toobtain the carbonate content. Insoluble residue(IR) content is determined by the sum of TOCand carbonate content, subtracted from 100%. Ifthe deviations between the double measure-ments exceeded 0Æ05 wt% TOC or 0Æ5 wt% TC,a third run was performed.

Mineralogy

X-ray diffraction was used to analyse the min-eralogy of the bulk sediment. After hand grind-ing, the samples were measured with a PhilipsX-ray diffractometer (Phillips Electronics, Eind-hoven, The Netherlands) at IFM-GEOMAR (Kiel,Germany) composed of a goniometer (PW 1820),a control unit (PW 1710) and a generatorcontaining a cobalt anode (PW 1830). A 2hangle between 20� and 40� was chosen to coverthe main peaks of the major carbonate minerals(aragonite, HMC, LMC, dolomite) and quartz.Measurements were performed at 40 kV and35 mA with a scanning speed of 0Æ01� sec)1.The amount of carbonate minerals relative to thetotal carbonate content was calculated using thepeak area ratio (Milliman, 1974). The peak areaswere determined using the MacDiff 4.0.7 soft-ware. An in-house calibration curve was used toaddress the non-linear relationship betweenaragonite and calcite (Roth, 2003). In order toestimate the real carbonate content from Dumascombustion analysis, the amount of Mg incor-porated in the HMC has to be known (mol.%MgCO3). A linear relationship between MgCO3

content and d-values of the individual HMCpeaks was used to calculate the mol.% MgCO3

(Goldsmith & Heard, 1961; Lumsden, 1979).

Mass accumulation rates

Unlike linear sedimentation rates (LSR; centi-metres of sediment per 1000 years), MARs takethe physical properties of the sediment intoaccount, such as density and water content anddisplay the weight of sediment deposited on afixed surface over a period of time (grammes ofsediment per square centimetre and kiloyear).MARs enable discrimination between sedimentcomponents and thus allow the calculation of theaccumulation of individual carbonate phases,aragonite, LMC and HMC, within a distinct timeinterval. MARs were calculated after Ehrmann &Thiede (1985).

Grain-size distribution

The grain-size distribution was calculated fromthe weight of the different grain-size fractions.First, the dry bulk sediment was weighed. Duringwet sieving the fine fraction (<63 lm) was separ-ated from the >63 lm sediments. After wet siev-ing the >63 lm fraction was oven-dried at 60 �Cand weighed again. To obtain the amount of thedifferent grain-size fractions, the dried coarsefraction (>63 lm) was dry sieved using a sieve setwith mesh widths of 125, 250, 500 and 1000 lm.Relative distribution values (in percentages) werecalculated using the weight of the dry bulksample and of the six grain-size fractions <63,63 to 125, 125 to 250, 250 to 500, 500 to 1000 and>1000 lm.

RESULTS

Core description

Sediments of core MD992202 are white togreenish, unlithified, nearly uncompacted andmainly show a homogeneous appearance withrespect to colour and grain-size (Fig. 3A). The

Fig. 3. (A) Slightly bioturbated section showing themainly homogeneous appearance of the sediments ofcore MD99202 (2496 to 2521 cm); (B) grain-supportedsection containing cemented debris (119 to 150 cm).



matrix mostly consists of mud and silt (<63 lm).The sediments can be classified as wackestonesto packstones. Biogenic components consist ofshells of brachiopods, gastropods, bivalvesand serpulids, echinoderm spines and spongespicules as well as planktonic and benthicforaminifera. Throughout the entire core, thesediments show minor to moderate bioturbationand very good sorting, except for the sectionscontaining cemented debris (Figs 3B and 4A),which are mainly non-bioturbated and poorlysorted (varying from mud to gravel up to 6 cm indiameter). These sections are distributed atirregular intervals throughout the core (Fig. 4A)and show a mud-supported to clast-supportedappearance. The individual cemented clasts aresub-rounded to rounded and contain skeletalcomponents such as foraminifera, gastropods,bivalves and echinoderm spines.

Construction of the age model

The age model is a prerequisite for the presenta-tion of the results. A climate–stratigraphic agemodel was established by biostratigraphy andgraphical correlation of the stable oxygen isotopecurve (G. ruber), developed in this study with thed18O record of the SPECMAP ice core (Imbrieet al., 1984) using the computer software Analy-Series (Paillard et al., 1996).

Radiocarbon measurementsIn total, six radiocarbon measurements were made.Figure 4B and Table 1 present the results of thesemeasurements. The radiocarbon age dates given bythe majority of the samples, however, do not agreewith the biostratigraphic age dates and the oxygenisotope stratigraphy (see below). The sample at200 cm (>49 850 yr BP) is older than the under-lying sample at 310 cm (42 500 + 1530/)1280 yrBP) which, in this case, might suggest the redep-osition of older material. The two oldest samples(at 750 and 1000 cm), however, show ages youngerthan the sample at 430 cm (48 180 + 3440/)2400 yr BP). It remains unclear what processmight have caused this age inversion. Because ofthe significant discrepancy between the radiocar-bon ages and the other stratigraphic data, as well asthe aforementioned inversions, it was decided notto use the majority of the AMS 14C dates for thistime–stratigraphic age model.

Biostratigraphic analysisFifteen representative samples were chosen forcalcareous nannofossil biostratigraphy (Fig. 4 and

Table 2). In the lowest section of the core, nospecimens of P. lacunosa were found, indicatingthat the core does not reach MIS 12. Samples fromthe base of the core until 1238 cm show a cleardominance of G. caribbeanica. The first rareoccurrence of E. huxleyi is observed at 1058 and818 cm. E. huxleyi remains rare at 436 cm andbecomes more dominant in the samples at 192and 20 cm. In the samples where E. huxleyi israre, small Gephyrocapsa dominate the assem-blages, a feature that is common in MIS 5 insubtropical environments.

Based on the calcareous nannofossil observa-tions, the following age constraints can be made.The lack of P. lacunosa from the base of the coreindicates that the core does not reach MIS 12. Thelowest occurrence of E. huxleyi indicates that thecore is younger than MIS 8 from 1058 cmupwards. The lowest occurrence of this markerspecies is generally difficult to establish becauseof its small size and its rare contribution to thetotal nannoplankton assemblage. However, itagrees well with the dominance interval ofG. caribbeanica, which was observed up to1238 cm. Both the first occurrence of E. huxleyiand the dominance of G. caribbeanica are inconflict with the two oldest AMS 14C dates, butagree well with the proposed oxygen isotopestratigraphy. Besides the relatively difficult iden-tification of the lowest occurrence of E. huxleyi,the rise to dominance of this species only takesplace in the very uppermost section of thecore, indicating that a number of 14C ages areerroneous.

Oxygen isotope measurementsIn total, 323 d18O measurements on G. ruber(white) were performed. The derived d18O valuesrange from )1Æ59& at 20 cm to 1Æ84& at 484 cm(Fig. 4B). According to the incorporation of d18Ointo the shells of foraminifera, distinct sea-levelfluctuations are recorded and a classification intoMIS was performed (see Materials and methods).Core MD992202 comprises MIS 1 to 11. MIS 11is equivalent to the interval from 2595 to2498 cm. MIS 10 comprises the interval from2498 to 2218 cm. MIS 9 matches the depth from2218 to 1318 cm, MIS 8 from 1318 to 1138 cm,MIS 7 from 1138 to 598 cm, MIS 6 from 598 to470 cm, MIS 5 from 470 to 192 cm and MIS 4 toMIS 2 comprise the interval between 192 and68 cm. MIS 1 is established from depth 68 cm upto the core top. According to the SPECMAP agescale, the oldest sediments of core MD992202show an age of approximately 375 000 yr BP.



A B

Fig. 4. (A) Lithology of core MD992202 displaying the grain-size of the matrix, degree of bioturbation, sectionscontaining cemented debris and sorting (depth scale); (B) oxygen isotopes, samples for nannofossil biostratigraphy(x), radiocarbon ages, correlation of d18O curves of core MD992202 (depth scale) versus SPECMAP ice core (age scale)and sub-division into marine isotope stages (MIS) 1 to 11; glacials: white, interglacials: grey.



Organic carbon, carbonate content andinsoluble residue

The TOC values are generally low. The averagecontent during glacial stages (0Æ1%) is lower thanthat of interglacial stages (0Æ25%). The highestorganic contents are present within interglacialMIS 9 (Fig. 5A and B). High TOC values are alsopresent within the stages MIS 7, MIS 5 and MIS 1,with the highest values mostly occurring duringthe first third of these stages. The TOC valuesshow an inverse correlation to variations in stableoxygen isotopes (R ¼ )0Æ76; Fig. 5A and B).

Carbonate content and insoluble residue (IR)content seem to be independent of glacial tointerglacial variations (Fig. 6A). This fact is mostprobably related to the small variance of theoverall high carbonate content (90 to 96Æ5 wt%).

Mineralogy

Aragonite and calcite dominate the sediments ofcore MD992202. Calcite occurs as HMC and LMC.

Quartz and dolomite are present in negligibleamounts. Aragonite, HMC and LMC show strongvariations in relative abundance (Fig. 6B).Although aragonite is the dominant mineral inmost of the samples (avg. 63%), it exhibits varia-tions between 8 and 92Æ5 wt%. Glacial mineralogydisplays much higher average HMC values(47 wt%) compared with interglacial stages(13 wt%; Figs 6B and 7). In contrast, aragonitehas lower average values in glacial stages (33 wt%)than in interglacial stages (78 wt%). The oxygenisotope variations and the aragonite content of coreMD992202 show a clear anticorrelation(R ¼ )0Æ85), in which samples with higher ara-gonite content in general have lower d18O valuesthan those with lower aragonite content.

Generally, LMC shows increased average valueswithin glacial stages (glacial average: 19Æ5 wt%;interglacial average: 11 wt%; Figs 6B and 7).Although the highest LMC values are recordedduring MIS 10, other stages also show largeinternal variations in LMC. The latter variationsexceed the glacial/interglacial changes and, there-fore, LMC variations do not seem to be a goodindicator for glacial to interglacial changes.

Mass accumulation rates

The MAR values vary between 2 and54 g cm)2 kyr)1 (avg. 12 g cm)2 kyr)1). Becauseof uncertainties regarding the age model, nospecific intervals of the accumulation rates arediscussed. Therefore, interglacial and glacialaverage values are used to give an overview ofthe general relationship between mass accumula-tion rates and sea-level fluctuations.

Grain-size distribution

The grain-size in glacial stages is considerablycoarser than in interglacial stages. Whereas inter-glacial stages display average values of the finefraction (<63 lm) of 70Æ5 wt%, glacial stagesshow average values of 49 wt%. The fine fraction(<63 lm) dominates most parts of coreMD992202. Low values in the fine fraction aremainly characterized by high relative amounts ofthe grain-size fraction >1000 lm (Fig. 6C). Themost pronounced grain-size variations are dis-played at the transitions of the MIS. Maxima ofthe grain-size fraction >1000 lm are present atmost of the transitions from glacial to interglacial(MIS 10 to MIS 9, MIS 8 to MIS 7, MIS 6 to MIS 5,MIS 2 to MIS 1) and interglacial to glacial stages(MIS 9 to MIS 8, MIS 7 to MIS 6, MIS 5 to MIS 4;

Table 1. Results of AMS 14C measurements of coreMD992202 based on G. sacculifer.

Core depth(cm)

Laboratoryidentifier

Radiocarbonage (yr bp)

20 KIA 22924 3005 ± 30200 KIA 22925 >49 850310 KIA 22926 42 500 + 1530/)1280430 KIA 22927 48 180 + 3440/)2400750 KIA 22928 >45 680

1000 KIA 22929 >47 320

Table 2. Biostratigraphic estimation of the MarineIsotope Stages (MIS).

Core depth (cm) Estimated MIS

20 MIS 1192 MIS 3 to 4436 MIS 5e558 MIS 6750 MIS 7998 MIS 7

1058 MIS 71238 MIS 81278 MIS 81398 MIS 91678 MIS 91998 MIS 92338 MIS 102418 MIS 102518 MIS 11



Fig. 5. (A) d18O values of core MD992202; (B) TOC content; (C) grain-size fraction >1000 lm. Age axis displayed onthe left; marine oxygen isotope stages (MIS) shown on the right; glacials: white, interglacials: grey.



A B C

Fig. 6. (A) LECO analysis; (B) mineralogy; (C) grain-sizes (for illustration reasons, the grain-size fractions 63–125 lm, 125–250 lm, 250–500 lm and 500–1000 lm were summarized to 63–250 lm and 250–1000 lm). Age axisdisplayed on the left; marine oxygen isotope stages (MIS) shown on the right; glacials: white, interglacials: grey.



Fig. 6C). The exception to the rule forms thetransition from MIS 11 to MIS 10, which showsno maximum in coarse-grained material.

INTERPRETATION AND DISCUSSION

The impact of sea-level variations (glacials/interglacials) on sedimentation patterns

Total organic content (TOC) is generally lowthroughout the entire core, never exceeding0Æ6%, although distinct fluctuations occur be-tween glacial and interglacial stages (Fig. 5A andB). The most pronounced TOC maxima preferen-tially occur during the early phases of MIS 9, 7, 5and 1 (Fig. 5A and B), which represent periods ofmaximum bank-top flooding. Because of thelarger production area, organic production onthe bank increased, leading to the highest exportrates of organic material from the bank top to theopen ocean during highstands. Glacial stages(MIS 10, 8, 6, and 4 to 2) are characterized byan average TOC content of 0Æ1%. During glacialphases, large parts of the platform were exposedand organic production was limited. This processresulted in decreased export of organic carbonfrom the bank top. The TOC contents are clearlyrelated to sea-level fluctuations, as supported bytheir good correlation with the stable oxygenrecord (Fig. 5A and B). Similar to the TOC values,the aragonite content of core MD992202 wasinfluenced by glacial/interglacial related sea-levelfluctuations as indicated by the correlation withthe oxygen isotope curve (high aragonite contentis accompanied by lower d18O values; R ¼ )0Æ85).This pattern of enhanced export of aragoniteduring sea-level highstands agrees with the ‘high-stand shedding’ model proposed by Droxler &Schlager (1985), Reijmer et al. (1988) and Schlag-er et al. (1994). In contrast, glacial mineralogy ischaracterized by high average HMC values incomparison with interglacial stages (Fig. 7) whichcan be best explained by the redeposition ofsyndepositional cemented material (mainlyHMC) from the upper slope (Grammer et al.,1993a,b), and a decreased aragonite input duringsea-level lowstands, when large areas of theplatform are exposed and could not contributeto aragonite production and export (Schlageret al., 1994). For the Northwest Providence Chan-nel, Boardman et al. (1986) proposed that aragon-ite production during sea-level lowstandsoccurred along the steep margin of the platform.In contrast to the flat-topped Great Bahama Bank

(GBB), the LBB is a flat-topped platform with anortherly attached shelf. Whereas carbonate pro-duction stopped on GBB during glacial lowstandswhile the entire production area was exposed, thenortherly attached shelf of LBB presumably wasstill partially flooded which allowed a downslopeshift of the carbonate factory, probably explainingthe continuing presence of aragonite in coreMD992202 during glacial phases.

Mass accumulation rates are clearly influencedby sea-level changes. The overall mass accumula-tion rate (MAROverall) in interglacial stages is twiceas high as in glacial stages (Fig. 8). Interglacialaverage aragonite accumulation rates (MARArag)with 11 g cm)2 kyr)1 are distinctly higher thantheir glacial counterparts (3 g cm)2 kyr)1). Whenthe sea-level was high, a large production area foraragonite existed and excess sediment could beexported to the open ocean. Glacial lowstandscaused a decrease in the production area andtherefore resulted in decreasing MARArag. En-hanced shedding of cemented debris led toincreased MARHMC, mainly not only during thetransitions of the marine isotope stages,but also during glacial lowstands (glacial aver-age: 2Æ5 g cm)2 kyr)1; interglacial average:

Fig. 7. Interglacial/glacial average values of miner-alogy within core MD992202.

Fig. 8. Interglacial/glacial average values of overallmass accumulation rates (MARs) and MARs of arago-nite (Arag.), high-magnesium calcite (HMC) and low-magnesium calcite (LMC).



2 g cm)2 kyr)1). Glacial stages show higherMARHMC, whereas interglacial stages are charac-terized by higher MARArag, again corroborating the‘highstand shedding’ model (Droxler & Schlager,1985; Reijmer et al., 1988; Schlager et al., 1994).

Grain-sizes in glacial stages are considerablycoarser than those found in interglacial stages(Fig. 6C), suggesting that the input of fine mater-ial from the platform top decreased during glaciallowstands (decreased input of aragonite) andredeposition events became more important. Sim-ilar grain-size variations were observed on theleeward western slope of GBB (Rendle et al.,2000; Rendle-Buhring & Reijmer, 2005), as well asin leeward and windward settings around theTongue of the Ocean (GBB; Grammer et al.,1993a). The most pronounced grain-size varia-tions exist at the transitions of the individualMIS. Maxima of the grain-size fraction >1000 lmare present at most of the transitions from glacialto interglacial (MIS 10 to MIS 9, MIS 8 to MIS 7,MIS 6 to MIS 5, MIS 2 to MIS 1) and interglacial toglacial stages (MIS 9 to MIS 8, MIS 7 to MIS 6,MIS 5 to MIS 4), respectively (Fig. 5C). Thisregular recurrent feature can, most probably, beexplained by redeposition events which willbe discussed in the next section. In summary,the variations in the sedimentation patterns ofcore MD992202, such as TOC, mineralogy, grain-size, MARArag and MARHMC show a strongdependence on sea-level fluctuations.

The redeposition events within coreMD992202

The sedimentation patterns present in coreMD992202 show distinct intervals characterizedby either: (i) fine-grained sediments with higharagonite contents (‘highstand shedding’ sedi-ments); or (ii) cemented debris accompanied byhigh HMC values. In contrast to the ‘highstandshedding’ sediments (i), the sections containingcemented debris (ii) are characterized by higherHMC values (marine cements) and a high contentof the grain-size fraction >1000 lm. The lattersediments are interpreted as being the result ofredeposition events (Figs 3B and 9). These redep-osition events produced debris flow deposits,consisting of massive, poorly sorted, mud-sup-

Fig. 9. Correlation of grain-size fraction >1000 lm(solid line) and relative HMC values (scattered line)and occurrence of redepositions. Age axis displayed onthe left; marine oxygen isotope stages (MIS) shown onthe right; glacials: white, interglacials: grey.



ported or clast-supported sediments. The irregu-larly rounded shape of the cemented clasts andtheir composition, including pteropods andplanktonic foraminifera G. ruber and G. sacculifer,implies reworking of cemented areas on the upperslope of the LBB and subsequent downslopetransport of the debris. Debris flows are generatedas soon as the applied shear stress exceeds theshear strength of the sediment (Einsele, 1991).Generally, this can be caused by several proces-ses, such as: (i) earthquakes; (ii) differentialcementation on the slopes; (iii) oversteepeningof the slopes because of high sediment input; and(iv) sea-level fluctuations changing the equilib-rium between pore-water pressure and hydrosta-tic pressure and altering the wave base (Cook,1983; Hilbrecht, 1989; Einsele, 1991; Grammeret al., 1993a). Additional loading of sediments byslides and slumps may also generate secondarymass movements (Cook, 1983; Einsele, 1991).Moreover, Grammer et al. (1993a) demonstratedthat recent upper slopes of the Tongue of theOcean (GBB) show numerous cracks, suggestingthat these slopes experienced initial failure. Withrespect to the process shaping the northernmargin of the LBB, Harwood & Towers (1988)proposed an association of debris flows withgully-wall collapses. As can be observed ontopographic maps and seismic profiles, thesegullies extend across the entire slope and repre-sent sediment pathways (Harwood & Towers,1988).

Redeposition events in core MD992202occurred mainly at the glacial–interglacial (MIS10 to 9, 8 to 7, 6 to 5 and 2 to 1) and interglacial–glacial transitions (MIS 9 to 8, 7 to 6 and 5 to 4).Redeposition events that occurred at transitionfrom glacial to interglacial stages are consideredas events associated with transgressions in sea-level (transgressive events). Conversely, regres-sive redeposition events occurred at the transitionfrom interglacial to glacial stages. Considering thestratigraphic distribution of redeposition events,sea-level fluctuations seem to be the dominantfactor triggering debris flows. For the westernslope of GBB, Henderson et al. (2006) proposednon-Milankovitch sea-level highstands at 185 ka,post-dating the expected end of MIS 7, and at343 ka, pre-dating full MIS 9 interglacial condi-tions. The age dates of these events agree verywell with the timing of redeposition eventsoccurring in core MD992202.

Although literature data suggest that slopefailure occurred more often during sea-levellowstands (Cook, 1983; Sarg, 1988), Grammer

et al. (1993a) suggested for the Tongue of theOcean that slope failures occur during transgres-sional phases as well. This study documents thatboth regressional and transgressional redeposi-tion events may take place in one depositionalsetting. The main physical processes are thoughtto be changes in hydrostatic pressure, the ratio ofhydrostatic to pore-water pressure, the level ofthe wave base and oversteepening of the slopes incombination with variable degrees of cementation(Hilbrecht, 1989; Grammer et al., 1993a). Thescenarios for regressive and transgressive redep-osition events are given in Fig. 10. Transgressiveredeposition events were initiated by an increasein hydrostatic pressure during sea-level riseleading to instability in formerly deposited sedi-ments (Grammer et al., 1993a).

During highstands in sea-level the bank-topsediment production was increased, which mayhave led to oversteepening of the slopes. A fall insea-level: (i) caused lowering of the wave base,which affected the sediment mobilization onthese oversteepened slopes by storm waves; and(ii) resulted in pore-water overpressure because ofdecreasing hydrostatic pressure (Hilbrecht, 1989).

In ancient deposits it will remain difficult todetermine the timing of slope erosion relative tosea-level. Lowstands are often suggested as thetime interval in which large-scale slope failuresand slope erosion might occur (see Handford &Loucks, 1993 for numerous examples). Moreover,earthquakes are often proposed as the triggeringmechanism for catastrophic collapse of carbonateplatform margins that result in the deposition ofmegabreccias on the slope and within the basin(Hine et al., 1992; Handford & Loucks, 1993;Drzewiecki & Simo, 2002). Only a few studiesrelate the emplacement of debris flows withprocesses associated with sea-level variations. Inhis study of Upper Cretaceous deposits, Hilbrecht(1989) proposed a regression-related mechanism,which might explain the frequent occurrence ofgravity-transported sediments in the basin. Cre-vello & Schlager (1980) analysed a big debris flowand associated turbidite deposits in ExumaSound (Bahamas), and related the emplacementof these deposits to a lowering in sea-level fromthe Sangamon highstand, 80 to 120 ka. In theirstudy of turbidite sequences on the MadeiraAbyssal Plain, Weaver & Kuijpers (1983) showedthat, at least for the last 340 ka, sea-level changesassociated with transgressions and regressionswere more important processes to trigger turbi-dites than other changes during the quiet periodsin-between. A similar association was observed in



the calciturbidite distribution pattern near PedroBank (Caribbean) by Andresen et al. (2003).These authors showed that the tectonic activityin the region played a minor role in the distribu-tion pattern of calciturbidites. They also demon-strated that turbidite input was not only linked toslope instabilities, caused by carbonate platformoverproduction (highstand bundling sensu Drox-ler & Schlager, 1985), but also to sedimentredistribution during changes in sea-level asso-ciated with transgressions and regressions.

CONCLUSIONS

A sedimentological study on core MD992202,retrieved from the northern slope of the LittleBahama Bank (27�34Æ45¢ N, 78�57Æ93¢ W) demon-strates the important role of climaticallycontrolled sea-level fluctuations on the sedimen-tation patterns present in periplatform sediments.Core MD992202 contains (i) mostly fine-grained

sediments, which are dominated by aragonite withminor high-magnesium calcite and low-magne-sium calcite, representing a mixture of particles ofshallow-water and pelagic origin (periplatformooze) and (ii) sections with cemented debrischaracterized by high HMC values. Aragoniteaccumulation was higher during sea-level high-stands than during glacial lowstands supportingthe ‘highstand shedding’ model (Droxler & Schla-ger, 1985; Reijmer et al., 1988; Schlager et al.,1994). In addition, HMC accumulation was higherduring glacial stages and sea-level lowstands.Because of sea-level highstands, organic contentsare higher in interglacial deposits than in glacialdeposits that formed during lowstands when largeparts of the platform were exposed. The highestexport rates of organic content occurred during thefirst third of the interglacial phases representingphases of maximum bank-top flooding.

The sections containing cemented debris areinterpreted as redeposition events and formedprimarily during transitions from glacial to inter-

Fig. 10. Scenarios for appearance ofredepositions during relative sea-level falls and relative sea-level rises(modified from Andresen et al.,2003).



glacial (transgressive events) and interglacial toglacial (regressive events) stages, respectively.Redeposition deposits are characterized by signi-ficantly higher values of the >1000 lm grain-sizefraction (cemented debris) and high HMC values.Lowering of wave base and pore-water overpres-sure because of decreasing hydrostatic pressureduring sea-level falls led to regressive redeposi-tion events, whereas increasing hydrostatic pres-sure during sea-level rises most probably led totransgressive redeposition events.

This study documents that both regressionaland transgressional redeposition events may takeplace in one depositional setting, a phenomenonthat has been largely under-represented in theliterature and, therefore, contributes to a betterunderstanding of sea-level related depositionmechanisms on carbonate slopes.

The exact timing of redeposition events in fossildeposits remains problematic because of temporaluncertainties. This study shows that a temporalclassification of sea-level related redepositionevents is possible. Additional high-resolutionstudies are needed to evaluate the differences andsimilarities of margin types, currents and slopemorphologies, and the associated timing of basinaldebris flow and turbidite deposition.

ACKNOWLEDGEMENTS

Special thanks go to the captain and crew of RVMarion Dufresne for technical assistance duringthe shipboard work. We thank the members of thecarbonate sedimentology group at IFM-GEOMAR,Germany for their support. Furthermore, wethank student assistants Jill Falk and Steffi Sch-midt for their help with the laboratory work. Themanuscript benefited from critical comments bySven Egenhoff (Freiberg University of Mining andTechnology, Germany). Special thanks go to JuttaHeinze, Sylvia Koch and Lulzim Haxhiaj for theirsupport during the measurements of X-ray dif-fraction, Dumas combustion analysis and massspectrometry.

This study was supported by the GermanScience Foundation, Images Program to J.R. andDFG-RE1051/9-2 to S.R. and J.R. (KLIBANK pro-ject). We especially acknowledge the constructivereviews of Giovanna Della Porta, G. MichaelGrammer and editor Isabel Montanez, whichsignificantly improved the manuscript. The spon-taneous SeaLaix-reviews of Andre Droxler andEduard Bard stimulated the re-evaluation of thetime-model.

REFERENCES

Andresen, N., Reijmer, J.J.G. and Droxler, A. (2003) Timing

and distribution of calciturbidites around a deeply sub-

merged carbonate platform in a seismically active setting

(Pedro Bank, northern Nicaragua Rise, Carribean Sea). Int. J.

Earth Sci., 92, 573–592.

Andruleit, H. (1996) A filtration technique for quantitative

studies of coccoliths. Micropaleontology, 42, 403–406.

Baumann, K.-H. and Freitag, T. (2004) Pleistocene fluctua-

tions in the northern Benguela Current system as revealed

by coccolith assemblages. Mar. Micropaleontol., 52, 195–

215.

Boardman, M.R., Neumann, A.C., Baker, P.A., Dulin, L.A.,Kenter, R.J., Hunter, G.E. and Kiefer, K.B. (1986) Banktop

responses to Quaternary fluctuations in sea level recorded

in periplatform sediments. Geology, 14, 28–31.

Bollmann, J., Baumann, K.-H. and Thierstein, H.R. (1998)

Global dominance of Gephyrocapsa coccoliths in the late

Pleistocene: selective dissolution, evolution, or global

environmental change? Paleoceanography, 13, 517–529.

Cook, H.E. (1983) Ancient carbonate platform margins, slopes

and basins. SEPM Short Course Notes, 12, 5.1–5.189.

Crevello, P.D. and Schlager, W. (1980) Carbonate debris sheets

and turbidites, Exuma Sound, Bahamas. J. Sed. Petrol., 50,1121–1148.

Dravis, J.J. (1996) Rapidity of freshwater calcite cementation;

implications for carbonate diagenesis and sequence strati-

graphy. Sed. Geol., 107, 1–10.

Droxler, A. and Schlager, W. (1985) Glacial versus interglacial

sedimentation rates and turbidite frequency in the Bahamas.

Geology, 13, 799–802.

Droxler, A.W., Schlager, W. and Whallon, C.C. (1983) Qua-

ternary aragonite cycles and oxygen-isotope record in

Bahamian carbonate ooze. Geology, 11, 235–239.

Drzewiecki, P.A. and Simo, J.A. (2002) Depositional proces-

ses, triggering mechanisms and sediment composition of

carbonate gravity flow deposits: examples from the Late

Cretaceous of the south-central Pyrenees, Spain. Sed. Geol.,

146, 155–189.

Ehrmann, W.U. and Thiede, J. (1985) History of Mesozoic and

Cenozoic Sediment Fluxes to the North Atantic Ocean.

Contrib. Sedimentol., 15. E. Schweizerbart’sche Verlags-

buchhandlung, Stuttgart, 109 pp.

Einsele, G. (1991) Submarine mass flow deposits and turbi-

dites. In: Cycles and Events in Stratigraphy (Eds G. Einsele,

W. Ricken and A. Seilacher), pp. 313–339. Springer, Berlin.

Emiliani, C. (1955) Pleistocene temperatures. J. Geol., 63,9538–9578.

Goldsmith, J.R. and Heard, H.C. (1961) Subsolidus phase

relations in the system CaCO3-MgCO3. J. Geol., 69, 45–74.

Grammer, G.M., Ginsburg, R.N. and Harris, P.M. (1993a)

Timing of deposition, diagenesis, and failure of steep

carbonate slopes in response to a high-amplitude/high-

frequency fluctuation in sea level, Tongue of the Ocean,

Bahamas. In: Carbonate Sequence Stratigraphy: Recent

Developments and Applications (Eds R.G. Loucks and J.F.

Sarg), AAPG Mem., 57, 107–131.

Grammer, G.M., Ginsburg, R.N., Swart, P.K., McNeill, D.F.,Jull, A.T. and Prezbindowski, D.R. (1993b) Rapid growth

rates of syndepositional marine aragonite cements in steep

marginal slope deposits, Bahamas and Belize. J. Sed. Petrol.,63, 983–989.

Handford, C.R. and Loucks, R.G. (1993) Carbonate deposi-

tional sequences and system tracts – responses of



carbonate platforms to relative sea-level changes. In: Car-

bonate Sequence Stratigraphy: Recent Developments and

Applications (Eds R.G. Loucks and J.F. Sarg), AAPG

Mem., 57, 3–41.

Harwood, G.M. and Towers, P.A. (1988) Seismic sedimento-

logic interpretation of a carbonate slope, north margin of

Little Bahama Bank. In: Proc. ODP Sci. Results (Eds J.A.

Austin Jr, W. Schlager and P.A. Comet), College Station, TX,

101, 263–277. American Association of Petroleum Geolo-

gists, Tulsa, OK.

Henderson, G.M., Robinson, L.F., Cox. K. and Thomas, A.L.(2006) Recognition of non-Milankovitch sea-level high-

stands at 185 and 343 thousand years ago from U-Th dating

of Bahamas sediment. Quatern. Sci. Rev., 25, 3346–3358.

Hilbrecht, H. (1989) Redeposition of Late Cretaceous pelagic

sediments controlled by sea-level fluctuations. Geology, 17,1072–1075.

Hine, A.C. and Neumann, A.C. (1977) Shallow carbonate-

bank-margin growth and structure, Little Bahama Bank,

Bahamas. AAPG Bull., 61, 376–406.

Hine, A.C., Wilber, R.J., Bane, J.M., Neumann, A.C. and

Lorenson, K.R. (1981) Offbank transport of carbonate sands

along open, leeward bank margins: Northern Bahamas. Mar.

Geol., 42, 327–348.

Hine, A.C., Locker, S.D., Tedesco, L.P., Mullins, H.T., Hal-lock, P., Belknap, D.F., Gonzales, J.L., Neumann, A.C. and

Snyder, S.W. (1992) Megabreccia shedding from modern,

low-relief carbonate platforms, Nicaragua Rise. Geol. Soc.

Am. Bul., 104, 928–943.

Imbrie, John, D., Hays, J.D,, Martinson, D.G., McIntyre, A.,Mix, A.C., Morley, J., Pisias, N.G., Prell, W.L. and

Shackleton, N.J. (1984) The orbital theory of Pleistocene

climate: support from a revised chronology of the marine

d18O record. In: Milankovitch and Climate 1 (Eds A.L.

Berger, J. Imbrie, H. Hays, G. Kukla and B. Saltzman), pp.

269–305. D. Reidel Publ, Dordrecht.

Leaman, K.D., Vertes, P.S., Atkinson, L.P., Lee, T.N.,Hamilton, P. and Waddell, E. (1995) Transport, potential

vorticity, and current/temperature structure across North-

west Providence and Santaren Channels and the Florida

Current off Cay Sal Bank. J. Geophys. Res., 100, 8561–

8570.

Lumsden, D.N. (1979) Discrepancy between thin-section and

X-ray estimates of dolomite in limestone. J. Sed. Petrol., 49,429–435.

Milliman, J.D. (1974) Recent Sedimentary Carbonates, Part 1,

Marine Carbonates. Springer-Press, Berlin, 375 pp.

Mullins, H.T., Heath, K.C., van Buren, M. and Newton, C.R.(1984) Anatomy of a modern open-ocean carbonate slope;

northern Little Bahama Bank. Sedimentology, 31, 141–168.

Neumann, A.C. and Land, L.S. (1975) Lime mud deposition

and calcareous algae in the Bight of Abaco, Bahamas: A

budget. J. Sed. Petrol., 45, 763–786.

Paillard, D., Labeyrie, L. and Yiou, P. (1996) Macintosh

program performs time-series analysis. EOS Trans. Am.

Geophys. Union, 77, 379.

Raffi, I., Backman, J., Fornaciari, E., Palike, H., Rio, D.,Lourens, L. and Hilgen, F. (2006) A review of calcareous

nannofossil astrobiochronology encompassing the past

25 million years. Quatern. Sci. Rev., 25, 3113–3137.

Reijmer, J.J.G., Schlager, W. and Droxler, A.W. (1988) Site

632: Pliocene-Pleistocene sedimentation cycles in a Baha-

mian basin. In: Proc. ODP Sci. Results (Eds J.A. Austin Jr, W.

Schlager and P.A. Comet), College Station, TX, 101, 213–

220. American Association of Petroleum Geologists, Tulsa,

OK.

Rendle, R.H., Reijmer, J.J.G., Kroon, D. and Henderson, G.M.(2000) Mineralogy and sedimentology of the Pleistocene to

Holocene on the leeward margin of Great Bahama Bank. In:

Proc. ODP Sci. Results (Eds P. Swart, G.P. Eberli, M. Malone

and J.F. Sarg), College Station, TX, 166, 61–76. American

Association of Petroleum Geologists, Tulsa, OK.

Rendle-Buhring, R.H. and Reijmer, J.J.G. (2005) Controls on

grain-size patterns in periplatform carbonates: marginal

setting versus glacio-eustacy. Sedimentary Geology, 175,99–113.

Roth, S. (2003) Holocene Climate Variations Recorded on the

Western Flank of Great Bahama Bank. Unpublished Ph.D.

Thesis, Christian-Albrechts-Universitat, Kiel, 124 pp.

Roth, S. and Reijmer, J.J.G. (2004) Holocene Atlantic climate

variations deduced from carbonate periplatform sediments

(leeward margin, Great Bahama Bank). Paleoceanography,

19, PA1003, doi:10.1029/2003PA000885.

Sarg, J.F. (1988) Carbonate sequence stratigraphy. In: Sea-levelChanges: An Integrated Approach (Eds C.K. Wilgus, B.S.

Hastings, H.W. Posamentier, J.C. Van Wagoner, C.A. Ross,

C.G.S.C. Kendall), SEPM Spec. Publ., 42, 155–182.

Schlager, W. and Ginsburg, R.N. (1981) Bahama carbonate

platform; the deep and the past. Mar. Geol., 44, 1–24.

Schlager, W. and James, N.P. (1978) Low-magnesian calcite

limestones forming at the deep-sea floor, Tongue of the

Ocean, Bahamas. Sedimentology, 25, 675–699.

Schlager, W., Reijmer, J.J.G. and Droxler, A. (1994) Highstand

shedding of carbonate platforms. J. Sed. Res., 64, 270–281.

Shackleton, N.J. and Opdyke, N.D. (1973) Oxygen isotope and

palaeomagnetic stratigraphy of equatorial Pacific core V28–

238: oxygen isotope temperatures and ice volumes on a

105 year and 106 year scale. Quatern. Res., 3, 39–55.

Stuiver, M. and Polach, H.A. (1977) Discussion: reporting of14C data. Radiocarbon, 19, 355–363.

Weaver, P.P.E. and Kuijpers, A. (1983) Climatic control of

turbidite deposition on the Madeira abyssal plain. Nature,

306, 360–363.

Williams, S.C. (1985) Stratigraphy, facies evolution, and dia-

genesis of Late Cenozoic limestones and dolomites, Little

Bahama Bank, Bahamas. Unpublished Ph.D. Thesis, RSMAS,

University of Miami, Fisher Island, Miami, FL, 489 pp.

Wilson, P.A. and Roberts, H.H. (1995) Density cascading:

Off-shelf sediment transport, evidence and implications,

Bahama Banks. J. Sed. Res., A65, 45–56.

Manuscript received 22 February 2007; revisionaccepted 26 April 2007



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