regional climates, whereas their comparison suggests broader North Pacific atmospheric circulation patterns and shifts. The Jellybean Lake d 18 O record is 7500 years long and d 18 O variations are interpreted as degree of fractionation during moisture transport from the Gulf of Alaska controlled by the intensity and position of the Aleutian Low. An intensified/eastward Aleutian Low is thought to correspond with lower d 18 O values, and vice versa. The Bison Lake d 18 O record is 10,000 years long and d 18 O variations are interpreted as seasonal precipitation balance controlled by winter Pacific storm tracks. Drought periods (i.e. drier winters and/or a more rain- dominated seasonal precipitation balance) generally correspond with higher d 18 O values, and vice versa. Comparisons with marine proxy data along the northeast Pacific margin are used to evaluate the hypothesis that climate patterns along the North American cordillera reflect changes in Pacific climate patterns such as ENSO and the PDO. ENVIRONMENTAL EVOLUTION OF THE MIRA ESTUARY (SW PORTUGUESE COAST) IN THE LATE QUATERNARY César Andrade. Centro de Geologia, Faculdade de Ciências da Unive, Portugal E-mail address: candrade@fc.ul.pt The Mira River outlets in the SW coast of Portugal, 120km south of Lisbon. It flows SE-NW for 140km before abruptly bending westwards in its terminal 5km. A number of sediment-choked flat-floored stream valleys meeting the main valley, together with expansions of tidal flats/salt marshes at the river margins constitute excellent sedimentary archives with potential to unravel the Pleisto-Holocene environmental evolution of this region. Three cores were drilled in these sediments (MA – Moinho da Asneira salt marsh, 3.5km landward of the coast, north margin of the main stream; CP – Corgo do Porto, 4km upcoast, alluvial plain of a tributary; VN1-Ch – salt marsh 5km upstream, south margin of the main stream) and studied for palaeoenvironmental proxies (sedimentology, geochemistry, micropalaeontology) and dated using 14C. Cores CP, 27m-long, and VN1-Ch, 43m-long, correspond to Holocene and Upper Pleistocene sediments directly resting upon Palaeozoic basement; MA core is 5.5m long and sampled materials accumulated from 5500 cal BP onwards. Results and interpretation of the studied proxies allowed recognizing the signal of the Holocene transgression in all cored areas, represented by a thick sequence of organic and bioclastic mud deposits, covering Pleistocene high-energy fluvial materials. The transgressive sediments settled in estuarine and progressively more open marine environments, until a transgressive maximum detected around 6000 cal BP at CP, after 4500-4000 cal BP at VN1-Ch and 2700 cal BP at MA. The age differences correspond to contrasting elevations of the surfaces drowned. Following this maximum, a forced regression is recorded in all sites, the terrestrialization corresponding to the establishment of an alluvial plain at CP and of marginal salt marsh expansions at MA and VN1-Ch. LATE PLIOCENE/EARLY PLEISTOCENE ENVIRONMENTS OF THE SIBERIAN ARCTIC INFERRED FROM THE LAKE EL'GYGYTGYN POLLEN RECORD Andrej Andreev. University of Cologne, Institute of Geology and Mi, Germany E-mail address: aandreev@awi-potsdam.de Continuous sequences that penetrates the entire Quaternary and further into the Pliocene is highly desired from the terrestrial Arctic. Such a record has now become available from Lake El’gygytgyn located in northeastern Siberia. The lake lies within a meteorite impact crater in Chukotka (NE Russia, 67  30' N, 172  05' E). The crater was created nearly 3.6 Million years ago in volcanic target rocks. The impact formed an 18-kilometer-wide hole in the ground that then filled with water. The retrieved lake sediments are trapped pollen from a several thousand square-kilometer source area providing reliable insights into over-regional millennial-scale vegetation and climate changes of the Arctic since the Pliocene. The international ’’El’gygytgyn Drilling Project“ of ICDP has completed three holes in the centre of the lake penetrating about 311 m thick lake sediments and about 200 m of the impact rocks below. The lowermost 200 m of the lacustrine sediments have been studied for pollen. The record documents palae- oenvironmental and palaeoclimatic changes during the Late Pliocene and transition to the Early Pleistocene. The revealed pollen assemblages can be subdivided into 10 pollen zones. The Pliocene pollen assemblages are so far dominated mostly by tree pollen. Repeated changes in the plant assem- blages through time reflect variations in forests of pine, larch, spruce, fir, alder, and hemlock. The tree pollen significantly decreases during the presumed Kaena subchron (3.1-3.03 Ma), concomitant with an increase in the relative abundance of wormwood pollen, spores of rock spike-moss, and coprophilous fungi. This pollen composition suggests treeless glacial environments, which can be described as tundra-steppe. The Pliocene/ Pleistocene transition (2.5 Ma) is broadly marked in the widely spaced samples studied so far by a distinct change from predominantly coniferous assemblages to pollen spectra dominated by dwarf birch, shrub alder, and herbs. A REVISION OF THE CAPRINAE (BOVIDAE, MAMMALIA) FROM THE PLIO-PLEISTOCENE OF SPAIN María Andrés. Departamento de Ciencias de la Tierra-IUCA, Univer, Spain E-mail address: mandresr@unizar.es Sheep and goats and their relatives (Caprinae) are an important compo- nent of the mammalian faunas from Eurasia since the Late Pliocene. Today, the Caprini are the most abundant caprines in Eurasia, but during the Pliocene they were the Ovibovini. Nevertheless, caprines are scarcely found in Plio-Pleistocene fossil sites. Because of this, the intraspecific morphological variability is unknown and the taxonomic determination is difficult in many cases. Furthermore, systematics and phylogenetic rela- tionships of these taxa have been controversial and are still unclear. Thus, some authors consider Megalovis latifrons, Hesperidoceras merlae and Pliotragus ardeus closely related forms that could well constitute a single species or evolving lineage and Kabulicornis ahmadi would be an earlier relative form of them. Hesperidoceras merlae is a quite rare bovid only found in Spain, in partic- ular in the Late Pliocene site of Villarroya. The only taxonomical study of this species was made by Villalta and Crusafont Pairo (1953), which included the skull and the teeth. However, the postcranial elements have never been studied. Here, we examine new material from the Villarroya fossil site and compared it with the related Plio-Pleistocene ovibovines above mentioned. The morphometric analyses (bivariate and principal component analyses) carried out on teeth and postcranial elements reveal clear differences among all the species. Our conclusions on the systematics and relationships of these species indicate that Pliotragus ardeus and Hesperidoceras merlae are not synonymous species. Current knowledge points out that Capra or closest relatives were not present in Iberian Peninsula until the Pleistocene. A LATE QUATERNARY HISTORY OF COASTAL PLAIN DEVELOPMENT RECORDED IN PALAEOSOLS AND SEDIMENTARY SUCCESSIONS Stefano Andreucci. University of Sassari, Italy E-mail address: sandreucci@uniss.it Alluvial fans combine palaeosol conservation, outcrop access, and extended time intervals. On the other hand, they host potentially ambig- uous palaeosol outcrops; pedocomplexes are the norm, and nature and position of stratigraphic boundaries cannot be taken for granted. Then, palaeosol research greatly benefits from detailed stratigraphic analysis which, in turn, greatly benefits from palaeopedology. Absolute dating is a requirement for solving stratigraphic ambiguities, even before it is needed for placing the record in its context. Alluvial fans in coastal settings are a link between marine and terrestrial environments. The Cecina valley (Tuscany) Pleistocene succession is a large sediment body recording a long-term sea level regression. The succession evolves from a fluvio-deltaic to an alluvial fan environment, and the upper portion was focused by our research. Integration of field skills was needed to reconstruct key surfaces. Back-to-back detail assessment of inconsis- tencies in soil profiles and facies overcame ambiguities. The succession records the transition from alluvial-fan conglomerate, from poorly confined, sediment-laden, flows, to channel-fill conglomerate, sandstone and mudstone. The latter attest to a fan entrenchment, within a long-term telescopic progradation driven by surface uplift and sea level changes. Fan Abstracts / Quaternary International 279-280 (2012) 9–120 19