Abstracts / Quaternary International 279-280 (2012) 462–565 511

Studies of European Pleistocene faunal remains tend to focus on individualsites or on evolutionary trends in specific lineages. Our knowledge of thesefaunas has now advanced to a level where it has become possible toinvestigate the intricate relationships between abiotic environmentalconditions, especially climatic and geographical factors, and communityprocesses. The high amplitude of the Pleistocene glacial-interglacial cyclesin Europe and the excellent faunal and floral records provide opportunitiesto examine the role of specific climatic and community processes in thedynamics of the mammal fauna.The Last Interglacial (oxygen isotope stage 5e) of north-west and centralEurope was characterised by an abrupt transition from cold glacialconditions to a temperate oceanic climate. The climate and largely forestedenvironment are thought to have been similar over large stretches ofnorthern Europe. Though the British Isles are climatically comparable tothe European mainland at this time, certain key species, notably hominins,horses and forest rhino, are missing from Last Interglacial faunas of theBritish Isles.To examine the causal factors behind these differences in faunal compo-sition, a variety of palaeoproxies (mammal remains, beetles and pollen) areinvestigated against a background of climatic data using a range ofmethods including environmental modelling, ecological analyses andmorphometric approaches. The detailed environmental and faunal recordfor the Last Interglacial allows for a comparison of the impact of both rapidclimate change and differences in community composition on thedynamics of the large mammal community between regions with similarclimatic conditions.

POSITION OF THE STEINHEIM INTERGLACIAL SEQUENCE WITHINTHE MARINE OXYGEN ISOTOPE RECORD BASED ON MAMMALBIOSTRATIGRAPHY

Eline N. van Asperen. Liverpool John Moores University, United KingdomE-mail address: envanasperen@palaeo.eu

The site of Steinheim (Germany) has been regarded as an iconic homininlocality for the Middle Pleistocene of Europe since the recovery of a hom-inin skull from the interglacial ‘Antiquus-Schotter’ of the River Murr in1933. The skull, attributed to Homo heidelbergensis, is considered to bemorphologically similar to the skull from the British Hoxnian site Swan-scombe. Based on stratigraphical considerations and the characteristics ofthe associated faunal assemblage, the site has generally been correlatedwith the Holsteinian Interglacial andmarine oxygen isotope stage (MIS) 11.However, over the last decades it has become apparent that many sitespreviously attributed to the Holsteinian Interglacial (sensu stricto) inactuality represent several temperate stages.During the late Middle Pleistocene, the caballoid horse lineage was char-acterised bychanges in size andmorphology under the influence of climaticoscillations in temperature and humidity, biogeographical and communityfactors. Significant differences in horse morphology can be observedbetween European late Middle Pleistocene sites dating from differentoxygen isotope stages. An analysis of caballoid horse remains from theSteinheim skull layer reveals clear morphological differences with horsefossils from British and German sites dated to MIS 11 and 9. A connectionwith MIS 9 material from southern France is suggested, implying a subdi-vision of the horse lineage into an eastern and a southern population, withan area of overlap in western continental Europe. As well as providinga relative date for the Steinheim site, these results indicate that biogeo-graphic factors should be considered in biostratigraphical correlations.

HOLOCENE SPATIAL AND TEMPORAL PATTERNS OF CARBON SEQUE-STRATION IN OMBROTROPHIC PEATLANDS OF QUEBEC, CANADA:IMPLICATIONS FOR GLOBAL RECONSTRUCTIONS

Simon van Bellen. Université du Québec à Montréal, CanadaE-mail address: van_bellen.simon@courrier.uqam.ca

Reconstructions of carbon sequestration in peatlands are often obtainedfrom single and long records sampled in central sections of the ecosystem.As peatland margins are often hydrologically and botanically distinct andlateral expansion rates may be related to local rather than external factors,reconstructions from a single core may poorly represent accumulationpatterns at the ecosystem scale.

We used multiple cores to reconstruct spatial and temporal carbonsequestration in three pristine, ombrotrophic peatlands (1.7-2.7 km2) inthe Eastmain region of boreal Quebec, Canada. Peatland depth wasmodelled by kriging after extensive manual probing and ground-pene-trating radar analyses. Peat carbon density was quantified after bulkdensity and loss-on-ignition analyses.At the ecosystem scale, Holocene carbon accumulation rates averaged 16.2g m-2 yr-1, with a mean age of peat inception of 5.1 ka BP. Site-specific age-depthmodelling shows a long-term decrease in vertical peat accumulationafter initial peat inception between 7.5-7.0 ka BP for each peatland, whilelateral expansion rates culminated in the earliest stages of bog historybetween 7.0-6.0 ka BP. Except for a shift at the acrotelm-catotelmboundary, carbon density did not show a consistent increasing trendtowards older peat. Combining vertical peat accumulation, lateral expan-sion and carbon density data, the most important period of carbonsequestration was centered between 5.0-3.0 ka BP.These results show that reconstructions of both vertical accumulation andlateral expansion patterns are essential to accurately quantify carbonsequestration at the ecosystem scale and that reconstructions based onvertical rates only may provide erroneous interpretations. Moreover, aschanges in expansion rates have previously been linked to local variabilityin basin morphology rather than climate factors, this implies that pastsequestration might have been controlled to a greater extent by local,geomorphological conditions than previously thought.

APPLICATION OF TEPHROCHRONOLOGY IN THE KURILE-KAMCHATKAAND ALEUTEAN MARGINAL SEA-ISLAND ARC SYSTEMS (KALMAR-PROJECT)

Christel van den Bogaard. IFM-GEOMAR, GermanyE-mail address: cbogaard@ifm-geomar.de

KALMAR aims at investigating the geosystem “Kurile-Kamchatka-AleuteanArc“ and its interaction with the climate system onshore Kamchatka andoffshore in the NW Pacific and the Bering Sea. The complex system iscontrolled by the most active volcanoes on earth and allows the study ofthe flux rates of material from mantle to atmosphere as well as theinteraction of the asthenosphere, hydrosphere and the atmosphere.Environmental changes during the Pleistocene to Holocene are inferredfrom both marine and lake sediment cores that give insight into climate-driven changes in palaeoceanography as well as ecological and limnolog-ical changes in the terrestrial realm, respectively. Marine sediment coreswere taken from the NW-Pacific and the Bering Sea during cruise SO201 ofresearch vessel 'SONNE' in 2009, while lake records were obtained fromTwo-Yurts Lake and Lake Sokoch on Kamchatka peninsula in summer2007.Various tephra layers were identified in the sediment cores. Toenable a long distance correlation of individual tephra layers a reliablefingerprinting of the volcanic ash was aimed at by EMP and LA-ICP-MSglass analyses.In the poster aspects of this study are shown as well asimplications of the correlations that link various geological records. Thestudy will permit the comparison of paleoclimatic, paleoceanological andvolcanological records. The study contributes to understand the volcanicand magmatic evolution of the Kamchatka-Aleutian Triple Junction.

TOWARDS ABSOLUTE POLLEN SAMPLING IN SURFACE MOSS

Pim van der Knaap. Institute of Plant Sciences & Oeschger Centre for,SwitzerlandE-mail address: pim.vanderknaap@ips.unibe.ch

Modern palynological studies require a good understanding of biases inpollen deposition and often use comparisons of modern pollen assem-blages with vegetation. Modern pollen is often collected as moss samples.The question on how the moss should be collected and how well itrepresents the average pollen deposition is relevant to existing datasetsand to the design of new studies. Here we evaluate the composition andabsolute content of pollen in moss samples against long pollen monitoringseries by means of modified Tauber Traps as employed in the PollenMonitoring Programme. We developed a semi-quantitative way of mosssampling for calibration with pollen trap results: pre-defined surfaces (22cm2) of moss were sampled close to each of 12 pollen traps in the Swissmountains. Each sample was split in a sub-sample consisting of the upper

Abstracts / Quaternary International 279-280 (2012) 462–565512

green moss and a sub-sample of the directly underlying brown and well-preserved moss. The time represented by the pollen in each top sub-sample and in each complete sample (both sub-samples) was estimated intwo different ways. Method 1, based on accumulation, derives the numberof years in moss by dividing the pollen accumulation per cm2 of the top-10trees in moss by their PAR in the associated traps. Method 2, based onpercentages, searches for the smallest squared chord distance (SCD)between the pollen percentages of the top-10 trees in moss and in asso-ciated traps averaged over the last 1 to 10 years. The number of years of themulti-year trap data associated with the smallest SCD represents thenumber of years in the moss. Pollen accumulations suggest that the topmoss sub-samples contain on average about half of the annual pollendeposition and the total moss samples about 1.5 years. The percentage-based method results in nearly two times longer deposition times than theaccumulation-based method. Non-selective loss of pollen during deposi-tion, which decreases accumulation but does not affect percentages, mayexplain this.

DIFFERENTIATING RECHARGE MECHANISMS AND GROUNDWATERINPUTS IN A CARBONATE AQUIFER (NW-QUEENSLAND, AUSTRALIA)

Mira van der Ley. ANSTO, Institute of Environmental Research, AustraliaE-mail address: m.vanderley@unsw.edu.au

The NW of Queensland is a remote pristine and sparsely populated regionwith minimal groundwater monitoring infrastructure. This is a semi-aridclimatic region with monsoonal fronts between December and Marchbeing the main source of precipitation. While yearly rainfall averages 580mm, evaporation can reach 3000 mm. Only a limited number of streamsflowing north into the Gulf of Carpentaria sustain flow through the year.These are exclusively maintained by groundwater discharge during the dryseason. Furthermore, all perennial streams share the same headwaterlithology, consisting of an w80 m thick Cambrian marine-platformcarbonate sequence. A number of water samples have been collected fromperennial spring discharges and available wells downstream. Preliminaryresults suggest the presence of several aquifer systems operating atdifferent time scales. The shallow system has short residence times asindicated by 35S activities in stream waters. The very low SO4 concentra-tions of streamwaters (w1 mg/L) suggests that most sulfur in the shallowsystem is marine derived and related to the last monsoonal rainfallsevents. Intermediate systems discharge into perennial springs with longerresidence times, where no 3H activity is detected and 14C activities suggestsub-modern groundwater. The comparison of 87Sr/86Sr and REEs of locallithologies and water samples show the interaction between water,carbonates and Proterozic metasediments. This proves intermediatesystems either expand into underlying metasedimentary formations ormix with other sources prior to discharging in the springs. The deepestregional system contains palaeowaters (ca. 9000 a) that may have beenpartially recharged through carbonate lithologies but mostly flow throughunderlying Proterozoic metasediments, generally increasing in agetowards the N but also mixing with younger waters along deep faults andother regional structural controls such as the Riversleigh impact structure.

MULTIPLE PALEOHYDROLOGICAL PROXIES FOR WESTERN MONGOLIABASED ON LACUSTRINE OSTRACODES

Thijs Van der Meeren. Ghent University, BelgiumE-mail address: tvdmeeren@gmail.com

Lacustrine Ostracoda (Crustacea) allow paleo-environmental reconstruc-tions based on changes in species assemblage, morphometry and valvechemistry. We conducted surveys of the ostracode fauna of westernMongolia, which allowed to identify around 55 ostracode species, of whichseveral are ill-known or new to science. Multivariate statistical analysis,based on either living or subfossil ostracodematerial, indicates communityresponse to environmental variables like calcium, alkalinity, salinity andtemperature. Strong faunal turnover corresponds well with solute evolu-tion from relatively Ca-enriched groundwater to the highly alkaline watersof saline lakes. An ostracode-based transfer function for calcium contenthas good statistical performance and provides a valuable approach to infergroundwater discharge into lakes. We also explored the intra-specificmorphometric response to environmental gradients in Limnocythere

inopinata. Valve outline measurements in a 15-site calibration datasetconfirmed consistent morphometric variation along the hydrochemicalgradient, and suggests potential for morphometry-based inferences inlow-diversity assemblages of dynamic saline environments. To exploit thegeochemical record of ostracode calcite, we compared the valve chemistryfingerprint (d 18O, d 13C, Mg/Ca, Sr/Ca) of live-captured L. inopinata femalesto ambient water chemistry. This suggested that adult valves of this speciescalcify epibenthically during the warm season in the shallow littoral zone.In connection with the regional gradient in solute evolution, this high-lighted the potential of Mg/Ca as a proxy for salinity, provided that thehydrochemical evolution of the studied water body is similar to that of theregional gradient. This work thus quantified ostracode response to theregional hydrochemical gradient at different levels (valve chemistry,species and community), providing a solid framework for ostracode-basedpalaeohydrological reconstruction in the region.

LATE HOLOCENE PALEOHYDROLOGICAL CHANGES FROM DUNE-ASSOCIATED LAKES IN WESTERN MONGOLIA AS WINDOWS TOWESTERLY DYNAMICS

Thijs Van der Meeren. Ghent University, BelgiumE-mail address: tvdmeeren@gmail.com

Late-Holocene records from two dune-associated freshwater lakes inwestern Mongolia are compared in order to detect coeval changes ininferred local water budgets pointing to regional trends in climate vari-ability. These regional shifts are interpreted in terms of past dynamics inmoisture supply. Bulk sediment composition, ostracode species composi-tion and valve chemistry (stable isotopes and trace elements) providedfairly robust scenario's for the lakes’ evolution, with small inferredamplitudes of hydrochemical shifts reflecting their through-flow nature.Three intervals, each encompassing excursions of greater effective mois-ture, represent major periods of regional climatic variability: 2700-2300,1800-1500 and 1300-1000 yr BP. A more recent (400-200 yr BP) periodwith concurrent hydrological shifts invoked divergent trends. Theseoverall patterns partly correspond with other climate records from thearea, corroborating that moisture supply by mid-latitude westerliesgoverns regional Late-Holocene climate variability in western Mongolia.Yet, substantial heterogeneity among regional records and among instru-mental precipitation data confirms that topographic complexity stronglycontrols spatial patterns in regional moisture. On Late-Holocene timescales, direct links between climate variability in Central Asia and atmo-spheric circulation in the North Atlantic Ocean may be difficult to discernbecause of different reasons. Westerly flow is modulated by other regionalmodes of atmospheric circulation (e.g. Siberian High), the stability of NorthAtlantic climate modes (e.g. North Atlantic Oscillation) on this time scale isunknown, and there is possible superposition of regional rainfall responseto solar variability. Paleolimnological work allows to further increase thespatial resolution of Late-Holocene moisture inference, and reveal thedifferential regional responses to changes in strength and position of thewesterly flow.

THE VALUE OF NUMERICAL MODELING OF AQUIFERS IN DATA-POORREGIONS

Martine van der Ploeg. Wageningen University, NetherlandsE-mail address: martine.vanderploeg@wur.nl

Studies on the Earth's hydrology in general thrive on abundant data, whiledata on certain groundwater systems are virtually absent as a result oftheir inaccessibility. This poses challenges for modeling such systems, yetmodeling is often the only option to study inaccessible systems. The levelof complexity that is needed in a model knows two fundamentalapproaches: either begin with the simplest model possible that is able toreproduce themeasured system behavior, or assume that a complexmodelwill be right when the conceptualization of all the important individualprocesses is right (Grayson and Bloshl 2000). When it comes to limiteddata availability, a simple model may have a better predictive performancethan a complexmodel (Grayson and Bloshl 2000). Both Oreskes (1994) andYe et al. (2008) state multiple interpretations regardless of the availabledata are possible as the environment is an open and complex system.Using multiple interpretations of a system by making different