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Benthonic marine species show a wide range of biological reactions to seawater chemical changes through time, from subtle adjustments to extinction. The Early Toarcian Oceanic Anoxic Event (T-OAE) was recently recognized in the Neuquén Basin, Argentina, confirming its global scope. The event was identified chemostratigraphically on the basis of a relative increase in marine organic carbon and a characteristic negative carbon-isotope excursion (δ13Corg) in bulk rock and fossil wood in the upper Pliensbachian–lower Toarcian interval in the Arroyo Lapa section (Neuquén). Simultaneously with collection of lithological samples, a high-resolution biostratigraphical survey was carried out, and the scarce benthonic fauna was collected in order to check the biotic response to changing marine geochemical conditions. We present here an analysis of size and abundance data from the T-OAE interval in the Neuquén Basin for the dominant bivalve species, the paper-clam Posidonotis cancellata (Leanza), and relate these data to geochemical proxies (%TOC and δ13Corg) obtained at the same locality. The abundance of P. cancellata increased when the rest of the benthos diminished, reaching a maximum at the onset level of the T-OAE, and then decreasing. Size-frequency distributions show a noteworthy lack of juvenile shells. Shell size shows a positive correlation with %TOC in the whole section, though over the T-OAE interval proper, it decreases below the level where the maximum %TOC value is attained and increases above it. Posidonotis cancellata shows features of opportunistic species, such as high tolerance to hypoxia, strong dominance in impoverished environments and a strong dependence on primary productivity, but at the same time had a reproductive strategy more similar to equilibrium species, with relatively low juvenile mortality rates. Several anatomical features suggest adaptation to permanently dysaerobic environments. The species disappeared just before the minimum negative carbon-isotope value was reached; and by the same time the genus became extinct worldwide. Fil: Ros Franch, Sonia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Echevarría, Javier. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Damborenea, Susana Ester. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Manceñido, Miguel Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Jenkyns, Hugh C.. University of Oxford; Reino Unido Fil: Al Suwaidi, Aisha. Khalifa University Of Science And Technology; Emiratos Arabes Unidos Fil: Hesselbo, Stephen P.. University of Exeter; Reino Unido Fil: Riccardi, Alberto Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina

A high-precision geologic time scale is the essential key for understanding the Earth’s evolutionary history and geologic processes. Astronomical tuning of orbitally forced stratigraphic records to construct high-resolution Astronomical Time Scales (ATS) has led to a progressive refinement of the geologic time scale over the past two decades. In turn, these studies provide new insights regarding the durations and rates of major Earth events, evolutionary processes, and climate changes, all of which provide a scientific basis for contextualizing and predicting future global change trends. South China hosts some of the best-exposed and well-dated Neoproterozoic through Mesozoic stratigraphic sections in the world; many of which are suitable for cyclostratigraphy and calibrating the geologic time scale. In North China, several Cenozoic oil-bearing basins have deep boreholes with continuous sampling and/or well logging that enable derivation of astronomically tuned time scales for an improved understanding of basin evolution and hydrocarbon generation. This Special Issue focuses on case studies of astrochronology and applied cyclostratigraphy research using reference sections within China. In this introductory overview, we: (1) summarize all existing astrochronology studies of the Neoproterozoic through Cenozoic sections within China that have been used to enhance the international geologic time scale, (2) examine briefly the astronomically forced paleoclimate information recorded in various depositional systems and the modern techniques employed to analyze the periodicity of these signals encoded within the sedimentary record, and (3) summarize the 20 contributions to this Special Issue of Palaeogeography, Palaeoclimatology, Palaeoecology on 'Cyclostratigraphy and Astrochronology: Case studies from China’.

The stable oxygen isotope composition of phosphates (δ 18 O P ) extracted from vertebrate bone and teeth material is widely used for paleotemperature reconstruction over the Quaternary period. However, inconsistency in analytical and statistical procedures used by different researchers for recalculation of mean air temperatures from measured δ 18 O P values makes integration of different data sets challenging. Therefore, consistency in both stable isotope data processing and the application of appropriate statistical procedures is highly desirable. This paper evaluates the uncertainty associated with two most commonly used regression methods, least-squares inverted fit and transposed fit. We assessed the performance of both fits by designing ‘real-life’ experiments using various data sets. We used both regression models to reversely calculate the differences between actual recorded in ‘real-life’ values and values calculated from the regression models. Our calculations clearly show that the mean absolute errors are always substantially higher for the inverted fit and the transposed fit always returned mean values closer to the values measured in ‘real life.’ In all studied scenarios, the predictive models performed better than causal models, returning mean absolute errors by 12–65% lower. In the paper, we also examined the other main sources of uncertainty, concerns about calculation of δ 18 O P of phosphates from δ 18 O C of carbonates, averaging of δ 18 O W in precipitation and highlight major challenges in the field of phosphate stable oxygen isotope biogeochemistry. The estimation of paleotemperatures from isotope records could be improved by employing globally consistent calculation procedures.

L'Arbreda Cave is one of the southernmost of the Reclau Caves (Serinya, Girona, northeastern Iberian Peninsula), located between the west margin of the Pla d'Usall and the Serinyadell river, at an altitude of about 211 m a.s.l. The Pla d'Usall forms part of the Banyoles-Besald Basin, which is bounded by Eocene and Neogene reliefs. It is filled with sediments of Plio-Pleistocene age. The cave is a shelter formed by travertine cascades with a degree of karstification, and contains sedimentary deposits ranging from the end of the Middle Pleistocene to the Early Holocene, thus constituting an important archaeo-palaeontological record for an understanding of the prehistoric occupation of northeastern Iberia. It is one of the most complete and best-dated terrestrial sequences in Iberia from the Mousterian to the Early Holocene period. In this paper we present a palaeoenvironmental and palaeoclimatic reconstruction of the sequence based on non-flying small mammals (insectivores and rodents) and pollen analyses. The environmental and climatic results, together with the absolute dating of the sequence and direct comparison with NorthGRIP delta O-18 and the sea-surface temperatures (SST) of the Alboran Sea, allow us to identify various climatic periods within our sequence: a cold period between interstadials 12 and 10 in Level I, probably interstadial 10 in Level H-2 the Last Glacial Maximum (LGM) in Levels C and B, the Bolling-Allered interstadial (B/A) in Level A, and the Preboreal/Boreal (Pr/B) in the Terra Rossa Level We want to thank the editor Dr. Paul Hesse and the three reviewers (Prof. Gloria Cuenca-Bescos and two anonymous) for their comments that improve the final version of the manuscript. This paper is part of the projects HAR2013-48784-C3-2-P, CGL2012-38358 and 2014-SGR900. Excavations ara funded by "Conselleria de Cultura Generalitat de Catalunya". J.M. Lopez-Garcia is a beneficiary of a Beatriu de Pinos postdoctoral fellowship (2011BP-A200001) from the Generalitat de Catalunya, a grant co-funded by the European Union through the Marie Curie Actions of the 7th Framework Program for R + D

Reconstructing the phylogeny and biogeography of the Caribbean land snail Cerion requires a robust stratigraphic and chronological framework. To this end, we have determined the stratigraphic succession on San Salvador, a Bahamian island with a rich fossil and modern Cerion fauna. A primary purpose of this paper is to independently verify this succession through whole-rock and Cerion aminostratigraphies and AMS 14C-based age models. Over 150 individual Cerion shells were age-ranked from 140 ka to modern using stratigraphic position and reverse-phase HPLC (RPC) amino acid racemization, which was sufficiently sensitive to resolve stratigraphic subunits within the Holocene and late Pleistocene. A secondary purpose of this paper is to assess broad changes in the gross morphology (height, width) of supersets of Cerion from age-ranked lots spanning this ~ 140 kyr chronostratigraphy. Through each of the three interglacial sequences (i.e., marine isotope stages 5e, 5a, and 1), between-sample trends in mean gross morphology often greatly exceed within-sample variances (± 1σ). Live-collected Cerion exhibit a range in gross morphology that nearly encompasses that of the entire fossil sequence. A trend of increasing gross shell size characterizes each of the interglacial phases, with a major step-decrease between marine isotope stages 5a and 1. While between-unit variation is often great in Cerion from SSI, within-unit variation appears unimodal through the record.

The early Tournaisian (Carboniferous) stage represents a key episode in the evolution of vertebrates. It follows the end-Devonian Hangenberg extinction event, which led to a major perturbation to both terrestrial and aquatic vertebrate ecosystems, and resulted in a significant restructuring of assemblages. However, few faunal associ-ations of this age have been described, and our understanding of faunal turnover across the Devonian -Carboniferous boundary remains poor. In this paper, we present an analysis of coprolite material from early Tournaisian lacustrine facies at Celsius Bjerg on Ymer o in East Greenland, which overlies the world-famous latest Devonian tetrapod-bearing localities. Fifty-five coprolite specimens (defined as a single coprolite or a piece of shale containing coprolites) were analysed using propagation phase-contrast synchrotron micro -tomography (PPC-SR mu CT). Through a study of external morphology, shape and size combined with information about internal structures, we categorise coprolite morphotypes, and interpret their origin. Notably, we identify a greater number of coprolite morphotypes compared to vertebrate taxa known from skeletal material, indicating the existence of a cryptic ecosystem that has not yet been recovered as body fossils. Vertebrate diversity in the immediate aftermath of the end-Devonian extinction is inferred to have been higher than expected, and might have included transient faunal elements within an open system, perhaps involving marine basin connections. Our results show that coprolites offer an alternative fossil data source, revealing diversity that is otherwise not always captured by the skeletal record.

Altres ajuts: CERCA Programme/Generalitat de Catalunya The Guadalupian was a key epoch for the evolution of tetrapod faunas. It includes the earliest unambiguous occurrences of therapsids and stereospondyls (groups that later became dominant in terrestrial and freshwater environments, respectively) and the late Capitanian mass extinction event. The low-latitude faunas from this time interval, where sufficiently dated, comprise rare tetrapod body fossils whereas the most complete records are provided by ichnoassociations, especially coming from the Provence basins of France. In this paper, we revise the tetrapod ichnoassociation from the Pélitique Formation of the Le Luc Basin of Provence, identifying the following tetrapod ichnotaxa: Batrachichnus salamandroides (temnospondyls/lepospondyls), Capitosauroides talus comb. nov. (therocephalian therapsids), Dicynodontipus isp. (cynodont therapsids), Varanopus isp. (bolosaurian parareptiles), Hyloidichnus bifurcatus (captorhinomorph eureptiles) and Rhynchosauroides isp. (neodiapsid eureptiles). According to our revised ichnotaxonomy and stratigraphic correlations, we date the Pélitique Formation as late Capitanian and assign its tetrapod ichnoassociation to the newly defined Association V (Dicynodontipus sub-biochron of the Erpetopus biochron). The Pélitique Formation ichnoassociation shows a typical composition for a post-dinocephalian extinction ichnofauna, as shown by preliminary multivariate statistics on Guadalupian-Lopingian tetrapod ichnoassociations. It is similar to the contemporaneous skeletal faunas described from the mid- to high-latitude sites of Russia and South Africa and is arguably the earliest evidence of post-dinocephalian extinction recovery at low-latitudes. Our results confirm the global and abrupt impact of the late Capitanian terrestrial mass extinction and the subsequent recovery in the low-latitude realm. This extinction was probably time-equivalent with a global benthic marine mass extinction, and both events may have been linked to climatic perturbation caused by the Emeishian volcanic activity in China, which reached its peak around 260 Ma.

The Nihewan Basin in North China contains the densest concentration of early Pleistocene Paleolithic sites outside Africa. This paper introduces a new archaeological site complex at Madigou (MDG) that was systematically excavated from 2011 to 2014 in the northeastern part of the Nihewan Basin. The site contains fossils and well-preserved stone artefacts in fluvio-lacustrine sediments. Our magnetostratigraphic results situate the MDG sedimentary sequence in the early Brunhes normal chron and the late Matuyama reverse chron, including the Jaramillo normal subchron. The MDG artifact layers are positioned within the pre-Jaramillo Matuyama chron, with an estimated age of ca. 1.2 Ma, close to the onset of Mid-Pleistocene climate transition. The MDG core and flake technology includes bipolar flaking of siliceous dolomite cobbles, and freehand flaking of chert and brecciated chert block fragments. Mammalian fauna and pollen compositions indicate that the MDG hominins lived in an open habitat varying from lightly-wooded grassland to an ecosystem dominated by sparse steppe near the shore of the Nihewan paleolake. Our combined results in the fields of archaeology, paleontology, palynology and magnetochronology suggest that innovations in technological behavior may correlate with adaptations to high environmental variability during the start of Mid-Pleistocene climate transition.

Bouchal, Johannes Martin/0000-0002-4241-9075; Guner, Huseyin Tuncay/0000-0001-9742-1319 WOS:000478712100017 The early Miocene was a period of major palaeogeographic reorganization in the eastern Mediterranean region, during which time the Anatolian Plateau became subaerial and several intracontinental basins intermittently became connected to the Paratethys and Mediterranean seas. In this paper, we analyse early Miocene vegetation and climate using leaf records, palynological assemblages, and fossil wood at 36 localities from western and central Turkey, most of which have precise age control based on radiometric dating and mammal faunal ages. Using the leaf flora of Giivem (Bes Konak, Kesekoy), Climate Leaf-Analysis Multivariate Program (CLAMP) analyses and Koppen signatures were employed to infer a palaeoclimate typical of modern laurel forest regions. Based on the palynological records, abundance of various pollen-taxa was used as a measure of openness of vegetation and regional presence of major tree taxa. Most pollen floras are dominated by tree pollen (ranging from 85 to 98%) and indicated widespread afforestation. In the pollen diagrams, shifts in dominance from swamp forest elements (Taxodioideae) to well-drained forests (Pinaceae) indicate changes in lake levels or phases of basin development. Such shifts may have been associated with the development of more xeric forest vegetation. Wood anatomical features such as false tree rings further may indicate seasonal climate. Pollen diagrams and macrofossils reflect zonal and azonal broadleaf and needleleaf forest and extrazonal open vegetation. The latter occurred in areas with shallow soils on volcanic rocks or limestone (e.g. cycads, Dracaena), or coastal areas (herb dominance). Taxonomic composition and biogeographic affinities suggest laurel forest as a major forest biome on well-drained soils and ecotones between laurel forest and broadleaf deciduous forest biomes. A comparison with younger floras shows that these are neither more diverse nor more warmth-loving despite an increase in global temperature (Mid-Miocene Climatic Optimum) suggesting bottlenecks during previous (Oligocene) cooler times for warmth-loving taxa. Swedish Research Council (VR)Swedish Research Council; Scientific and Technologicl Research Council of Turkey (TUBITAK), 2219 Post-Doctoral Research Fellowship Program (2017/2)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [1059B191700382] Bob Spicer, Jakub Sakala, and Howard Falcon-Lang provided valuable suggestions to improve the manuscript. We thank the Turkish Ministry of Mining for permission to work at the lignite mines of Can, Soma, Deni, and Tavsanli, and Atay Holding for permission to work in the lignite mine of Sahnall. Financial support from the Swedish Research Council (VR) to TD is acknowledged. HTG was supported by The Scientific and Technologicl Research Council of Turkey (TUBITAK), 2219 Post-Doctoral Research Fellowship Program (2017/2), project no. 1059B191700382.

Archaeologists and palaeoecologists are increasingly turning to stable isotope analysis (δ13C, δ18O) of fossil bioapatite to examine interactions of human and animal populations. However, relatively few investigations have focussed on the identification of natural variation in comparable modern populations, particularly within the Australian context. In this paper, we present the first modern isotopic reference dataset for Tasmanian bare-nosed wombat teeth (Vombatus ursinus tasmaniensis). Samples for δ13Cbioapatite and δ18Obioapatite measurements were recovered sequentially at sub-monthly resolution from all tooth types. δ13Cbioapatite showed little variation within a seasonal sinusoidal pattern within the sample set (n = 24 wombats; 35 teeth) due to the homogeneous C3 distribution of plants in Tasmania. In contrast, δ18Obioapatite profiles varied seasonally, representing time periods of between 0.9 and 2.1 years in 95% of the sample. Significant differences between tooth types were found from intra-individual to inter-regional scales for both dental growth rates and isotopic values. The accuracy of season-of-death assessments differed across the island; those in eastern Tasmania were accurate in all instances whereas those in the west showed substantial inaccuracies. We suggest that this may be due to the elodont form of wombat dentition and the ecologically influenced seasonally varied diet in western Tasmania. As the rate of dental growth is positively correlated with the proportion of coarse vegetation within the diet, this seasonal variation is therefore likely to change how annual isotopic signals are incorporated into the enamel. These results highlight the need to understand the degree of species-specific isotopic variation at a range of scales before applying this technique to archaeological or palaeontological assemblages.

One of the most reliable proofs of terrestrial ice-free conditions within Stadials is the presence of terrestrial vertebrate fauna that require access to vegetation in the winter, for example sedentary birds such as Ptarmigans and herbivorous mammals in particular. The musk ox (Ovibos moschatus) is an example of the latter; modern-day distributions of this species are limited to areas with low snow accumulations. In this paper we discuss the discovery of musk ox bones in Norway. Recently obtained radiocarbon dates on this material demonstrate the presence of this species 41–35 cal kyr B.P. in southern Norway during late Marine Isotope Stage 3 (MIS3). Furthermore the dates have implications for the interpretation of climate and environmental conditions; indicating the existence of a small ice cap in the mountains and climate and vegetation supporting a large mammal fauna in South Norway at that time. publishedVersion

Flexible crinoids (subclass Flexibilia) likely originated from the cladid crinoid genus Cupulocrinus or one of its immediate ancestors in the Middle to Late Ordovician. A remarkably constant and clade-defining character of flexible crinoids is the possession of three plates in the infrabasal circlet of the calyx. This character was a significant morphological modification for the origin of the flexible clade, resulting from the reduction of the number of infrabasal plates from five plates in the ancestral cupulocrinid. Of 615 museum specimens of Cupulocrinus sp. for which the number of infrabasal plates could be determined, 21 specimens, or 3.4%, displayed a deviation from the normal five infrabasals. Of the aberrant specimens, fifteen have four infrabasal plates, and six have six infrabasal plates. An additional aberrant specimen has five infrabasals, with one significantly reduced in size. Although the number of infrabasals is typically thought to be constant within a species, this trait appears to have been variable in the immediate ancestor of flexible crinoids, in the time period just before the number of infrabasals became fixed at three for the Flexibilia. This paper documents the range of aberrations within the infrabasal circlet of Cupulocrinus and considers the implications for the origin of the flexible crinoids.

© 2017. A new Permian-Triassic boundary microbialite (PTBM) is described from the Xiajiacao section of western Hubei Province, South China. The new microbialite, 3.16. m thick, comprises a thin layer of stromatolite and a thick thrombolite unit. An irregular contact separates the uppermost Permian skeletal packstone from the post-extinction stromatolite, but it is not yet possible to discriminate whether it was formed by submarine solution in the wake of ocean acidification or subaerial exposure due to regional regression, or a combination of both. The stromatolite shows "cabbage-like" morphology, and the thrombolite is characterized by centimetric clotted texture. Abundant columns of the microproblematica structure Gakhumella, coccoid-like spheroids, bacterial clump-like spheroids, and hollow spheroids are recognized in both stromatolites and thrombolites and may have played an important role in accretion of the microbialites. Pyrite framboid analysis indicates that microbialites may have been affected by lower dysoxic to upper dysoxic conditions in the immediate aftermath of the Permian-Triassic extinction. Stratigraphic abundance of both high-temperature grains (β-quartz and glassy balls) peaked ~. 20. cm below the biotic extinction horizon, implying that either intensive volcanic eruption occurred only just prior to biotic extinction, or volcanism was still intensive during biotic extinction, but volcanic grains were not deposited in the Xiajiacao locality, likely due to the shallow, agitated environment caused by the regional regression. Overall, microbial bloom, indicated by the widespread PTBMs, seems to have been little affected by the contemporaneous volcanism. We thank both anonymous reviewers and editor Thomas Algeo for critical comments and constructive suggestions, which have greatly improved the quality of the paper. This study is partly supported by the 111 Program of China (B08030), two NSFC grants (41572091, 41402089), and one research grant from the State Key Laboratory of Biogeology and Environmental Geology (BGEG), China University of Geosciences (GBL11206). It is a contribution to the IGCP 630 “Permian–Triassic climatic and environmental extremes and biotic response”.

This paper presents a late Holocene chironomid-inferred record of July air temperature from a core obtained from Lake Uddelermeer in the Netherlands. The core interval, which dates from 2500 to 400 cal. yr. BP, was analysed at multi-decadal resolution for organic content, pollen, spores and NPPs (Non Pollen Palynomorphs), and chironomid head capsules. These proxies indicate that, from 2500 to 1140 cal. yr. BP, the lake was mesotrophic and sustained a Littorellion community, while the chironomid assemblage was dominated by littoral species associated with macrophytes. At 1140 cal. yr. BP, a shift in the lake ecology occurred from low-nutrient to high-nutrient conditions dominated by algae. This shift might be linked to a concurrent increase in human impact and is reflected in the chironomid assemblage by increases in eurytopic taxa, which are resistant to disturbances. Shifts in the chironomid record between 2500 and 1140 cal. yr. BP do not coincide with changes in lake ecology and are presumably driven by climate change. Using a Norwegian-Swiss calibration dataset as a modern analogue, we produced a chironomid-inferred temperature (C-IT) reconstruction. This reconstruction compares well to other regional temperature reconstructions in timing and duration showing a Roman Warm Period between 2240 and 1760 cal. yr. BP, a Dark Age Cold Period starting at 1760 cal. yr. BP and the Medieval Climate Anomaly beginning at 1280 cal. yr. BP. The C-IT record indicates a temperature drop of 1.5 °C from the Roman Warm Period to the Dark Age Cold Period. Findings improve knowledge of the first millennium AD in NW Europe, which was characterised by changes in landscape, vegetation, society and climate.

Made available in DSpace on 2018-12-11T16:49:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Medical Library Association Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Ichnology is an important tool for facies and sequence stratigraphic analysis, typically yielding greater resolution than that provided by body fossils. Less commonly, ichnofossils also can be applied to ichnostratigraphy, a variant of biostratigraphy that aids in determining stratigraphic age of sedimentary sequences. Previous publications on the Furnas Formation (Paraná Group, early Paleozoic of the Paraná Basin), have yielded different interpretations of age, depositional environment, and sequence stratigraphic framework. Deposition in fluvial environments has been proposed in many papers, although a tide-influenced marine context has been inferred since the presence of Cruziana and Rusophycus was reported during the 1990s. Sequence stratigraphic interpretations also differ, mainly regarding the presence or absence of a sequence boundary between the middle and upper units of the Furnas Formation. The absence of body fossils in all but the topmost part of the upper unit, which contains Lochkovian (Lower Devonian) palynomorphs and primitive plants, has precluded age determination for the Furnas Formation in general. Here, we demonstrate the utility of both ichnofacies and ichnostratigraphic analysis to elucidate such questions. The studied sections are located in the cities of Tibagi, Palmeira and Ponta Grossa (Guartelá, Sítio Canei and São Jorge sections, respectively). Seventeen ichnotaxa are recognized, doubling the number of previously known ichnotaxa: Cruziana acacensis elongata and Rusophycus acacensis n. ichnosp. (in the lower and middle units); Arthrophycus alleghaniensis, A. brongniartii, Rhizocorallium commune, Didymaulyponomos rowei and Heimdallia chatwini (middle unit only); Arenicolites, Cylindrichnus and Diplocraterion (lower and upper units); Lockeia siliquaria and Psammichnites implexus (middle and upper units); Rosselia socialis (upper unit); and Palaeophycus tubularis, Didymaulichnus lyelli, Skolithos, and Thalassinoides (all units). Assemblages of these ichnofossils are assigned to Skolithos and proximal Cruziana ichnofacies. Ichnologic data, combined with associated physical sedimentary facies associations, indicate predominantly tide-influenced marine depositional environments. The presence of ichnotaxa of stratigraphic value (Arthrophycus alleghaniensis, A. brongniartii and Cruziana acacensis elongata) in lower and middle units indicates an Early Silurian age. This, in turn, indicates that a significant unconformity exists between the middle and upper units of Furnas Formation. Although the precise magnitude of this stratigraphic gap is difficult to establish, this break likely is linked to the Late Silurian global regression. Unisinos University Geology Graduate Program, Av. Unisinos, 950, Cristo Rei Auburn University Department of Geosciences, 2050 Beard-Eaves Memorial Coliseum Universidade Estadual Paulista-UNESP/IGCE, Av. 24-A, 1515 Universidade Estadual Paulista-UNESP/IGCE, Av. 24-A, 1515 FAPESP: 1998/02183-3 Medical Library Association: 308563/2013-1 CNPq: 311473/2013-0 Medical Library Association: 459776/2014-2 CAPES: 88887.129752/2016-00

Understanding environmental conditions faced by hunter-fisher-gatherers during the Pleistocene and Holocene, and interpretation of subsistence strategies, social organisation and settlement patterns, are key topics for the study of past human societies. In this respect, oxygen isotope values (?18O) of mollusc shell calcium carbonate can provide important information on palaeoclimate and the seasonality of shell collection at archaeological sites. In this paper, we tested P. vulgata shells from northern Iberia as a paleoclimate archive through the study of shell oxygen isotope values and sclerochronology of modern samples. Results showed that limpets formed their shells close to isotopic equilibrium, with an average offset between measured and predicted values of 0.36?. This offset is significantly reduced with respect to those reported in previous studies, probably due to the use of highly resolved data on the isotopic composition of the water when calculating predicted values. Despite large intra-specific variability, shell growth patterns of P. vulgata revealed a common pattern of higher growth in spring and a growth cessation/slowdown in summer and winter. The seasonal growth cessation/slowdown did not exceed three months. Therefore, a correct interpretation of the season of shell collection is still possible. Reconstructed seawater temperature exhibited a high correlation with instrumental temperature (R2 =0.68 to 0.93; p b 0.0001). Despite periods of growth cessation/slowdown, mean seawater temperatures and annual ranges were reconstructed accurately. As demonstrated here, seawater temperature can be reconstructed with a maximum uncertainty of ±2.7 °C. Therefore, our study shows that oxygen isotope values from P. vulgate can be used for the reconstruction of paleoclimate and the season of shell collection This research was part of the projects NF100413 (Newton International Fellowship granted to IGZ) and HAR2013-46802-P (funded bythe Spanish Ministry of Economy and Competitiveness, MINECO).

Proximal alluvial sediments represent a useful sedimentary archive to reconstruct the tectono-climatic history of continental rift basins. However, poor dating of coarse fluvial successions usually prevents high-resolution distinction of tectonic and climatic processes, and thus good determination of process rates. This paper presents a dating study of Plio-Pleistocene Kalavryta river system during the early history of the Corinth Rift (northern Peloponnese, Greece) based on magnetostratigraphy and palynology. This river system developed across several active normal fault blocks that are now uplifted along the southern rift margin. The detailed sedimentary record constrains alluvial architectures from the proximal basin to the river outlet where small deltas built into a shallow lake. In four magnetostratigraphy sections the correlation to the reference scale relies on the identification of the Gauss/Matuyama magnetic reversal and biostratigraphic elements. The river system developed between about 3.6 to 1.8 Ma, with sediment accumulation rates (SARs) ranging from 0.40 to 0.75 mm yr−1. SAR is lower in the alluvial fans than in the deltaic system, and higher at the centre of the normal fault depocentres than at the fault tip. By comparison with worldwide Cenozoic SARs, our values are higher but lie in the same range as those determined in coarse alluvial foreland basins. Moreover, in the context of overfilled intra-mountainous rift basins, these rates are minimum values and can be used as a proxy for accommodation rate. Therefore, early rift stratal wedges and growth synclines attest high sedimentation rates and also high rates of tectonic processes. Finally, in the distal river system, floral compositions and changes of vegetation deduced from palynological data are coherent with alternating fluvio-deltaic and shallow lacustrine deposits, which are linked to relative base level variations. Dry/cool climate is preferentially recorded during periods of low lake level, while the warm/moist climate is mainly recorded in prodelta deposits during periods of high lake level. This correlation suggests that, despite the dominant control of active faulting, climate is a key control of syn-rift stratigraphic architectures.

International audience; Understanding the formation of the Qilian Shan in the NE Tibetan Plateau provides insights into the growth mechanisms of the northern portion of the plateau through time. The onset time of exhumation in the Qilian Shan is still debated. The Qinghai Nan Shan subrange, located in the southeastern Qilian Shan, is cut by the Yellow River that forms Longyang Gorge, providing a good vertical profile for thermochronological investigation of exhumation. In this paper, we reconstruct the cooling and exhumation history of the Eastern Qinghai Nan Shan using apatite fission-track(AFT) and apatite (Usingle bondTh)/He(AHe) thermochronological dating on basement rocks. The fission-track data display a marked age-elevation trend from Early Cretaceous (114–122 Ma) ages at the bottom of the canyon to Early-Middle Jurassic ages (165–180 Ma) at the top. Mean (Usingle bondTh)/He ages are mainly Early Cretaceous (97–128 Ma) with one Eocene outlier (42 Ma). Combined with fission track lengths, Dpar values and thermal modeling results, these data indicate that the study area resided above the closure temperature of AFT and AHe until Early Cretaceous. Rapid cooling occurred during the Early Cretaceous and early Cenozoic likely driven by the Lhasa and Indian blocks collision with the southern margin of the Asian continent. Nonetheless, since then exhumation was limited to less than a few kilometers in the study area. Combined with regional geological studies, the thermochronological analysis demonstrates that, since the Mesozoic, intense exhumation occurred simultaneously along the northern and southern margins of the Qilian Shan. Hence, we suggest that the geomorphic framework of the northeast margin of the Tibetan Plateau was established during the Early Cretaceous-early Cenozoic.

El Salt is an important reference site for understanding the extinction of Neanderthal populations in the eastern Iberian Peninsula during MIS 3. In this paper, we describe the small mammal assemblage from Stratigraphic Unit V, the youngest unit with evidence of human presence, based on nearly 1300 specimens. A total of seven rodents (Microtus arvalis, Microtus duodecimcostatus, Microtus cabrerae, Sciurus vulgaris, Arvicola sapidus, Eliomys quercinus and Apodemus sylvaticus), three insectivores (Talpa occidentalis, Crocidura sp., Sorex sp.) and one lagomorph (Oryctolagus cf. cuniculus) were identified. Palaeocological analyses point to drier conditions in this part of the stratigraphic sequence, supporting the hypothesis that an aridification scenario may have played a role in the extinction of the Neanderthal groups inhabiting this region of the Iberian Peninsula.

In this paper, we reconstruct palaeoclimate for the late Oligocene (Chattian) La Val plant assemblage of Spain (NE Iberian Peninsula). Our study employs both CLAMP (Climate Leaf Analysis Multivariate Program) and LMA (Leaf Margin Analysis), the first time these two techniques have been directly compared, and is based on 25 morphotypes (representing 23 taxa) of woody dicot leaves from a single stratigraphic unit (layer LV6). Both methods have provided a similar result. Although the standard deviation of LMA is higher than CLAMP, the results of LMA are coherent with CLAMP. The palaeoclimatic variables obtained from CLAMP shows a marked contrast between WMMT and CMMT and between 3-WET (836.3 ± 145.4 mm) and 3-DRY (113 ± 33 mm). Meanwhile, the GROWSEAS (9.30 ± 0.7 months) points out that the growth season lasted almost all the year. These variations signal a seasonal contrast, showing the existence of a dry season. Results indicate a warm temperate climate with hot and dry summers. The palaeoclimatic variables obtained using CLAMP are: MAT 17.2 ± 1.7 °C, WMMT 25.5 ± 1.3 °C, CMMT 10 ± 1.8 °C and GSP 1480 ± 204 mm. The palaeoclimatic variables obtained using LMA are MAT 17.11 ± 4.61 °C (regression equation for data from East Asia) and 16.8 ± 4.7 °C (regression equation for data from Europe). The palaeoclimatic values estimated from La Val site match those obtained from other Oligocene sites from Iberia (e.g. As Pontes site) that rely on different palaeoclimate methods. These palaeoclimatic values obtained from La Val are also similar to those from several Oligocene localities (e.g. the Rot flora) in Europe and reflect peak temperature corresponding to the late Oligocene warming episode.

Coprolites are commonly identified in the Pleistocene archaeo-palaeontological record. They have often been described as indirect evidence for the presence of carnivores (usually hyenids) during the formation of a depositional sequence. However, coprolites are a much larger source of information that can provide data relating to factors affecting an archaeological assemblage, including its taphonomic history and palaeoecology. In this paper, two fossil coprolite accumulations dating to the late Early Pleistocene are described: Level TD6.1 of Gran Dolina (Sierra de Atapuerca, Burgos) and Unit II of la Mina (Barranc de la Boella, Tarragona). The results highlight the morphological homogeneity of these hyena coprolites, despite a considerable variation in size. The presence of microspherulites is clearly identified in all of the analysed hyena coprolites. Their composition is rich in elements characteristic of bone-origin, such as calcium (Ca) and phosphorus (P). A major difference, however, differentiating the remains from these sites was a higher frequency of bone fragments in the la Mina coprolites, regarding to TD6.1. Pollen, spores, and palynomorphs are scarce in the samples from both sites, which in fact share similar ecological characteristics such as the presence of pine, wild grasses, and coprophilous fungi. Hyena coprolites are relatively easy to differentiate from those of other taxa; however, they show intra-specific similarities in their micro- and macro-morphology and composition, despite their wide size range. The species of hyenids responsible for the coprolites is not possible to identify based exclusively on the size range, and the importance of a multidisciplinary study of the latrines and the coprolites is discussed as a source of palaeoecological and taphonomic information. In this study, coprolites are analysed, compared, and attributed to a hyenid, identified as Crocuta crocuta in the case of TD6.1, but without specific attribution in the case of la Mina., The research at Barranc de la Boella has been carried out with the financial support of the Spanish Ministerio de Economía y Competitividad projects: CGL2012-38358; CGL2012-38434-C03-03; CGL2012-36682, and HAR2012-32548. The Generalitat de Catalunya, AGAUR agency, provided projects 2014SGR-901, 2014PBR-899 and the framework of CERCA Programme/Generalitat de Catalunya. Financial support for Barranc de la Boella fieldwork and archaeological excavations has been provided by the Ajuntament de La Canonja the Diputació de Tarragona and the Departament de Cultura (Servei d'Arqueologia i Paleontologia) (2014/100574) of the Generalitat de Catalunya. The research at Sierra de Atapuerca has been carried out with the financial support of the Spanish Ministerio de Economía y Competitividad and the Fondo Europeo de Desarrollo Regional (FEDER): CGL2015-65387-C3-1-P (MINECO/FEDER).

Analyses of stratigraphic sequences within the paleocanyons of the Hualapai Plateau, Arizona, are important because these deposits offer the only evidence for the Paleogene-Neogene geological history of the Grand Canyon area. In this paper, we focus on the origins and paleoenvironmental significance of the West Water Formation, located within the Milkweed and West Water paleocanyons on the Hualapai Plateau. We propose that the supposed “limestone unit” of the West Water Formation at and near its type section is not a limestone; rather, it is a 21 m-thick valley calcrete, overprinted by a ~ 1–2 m-thick pedogenic calcrete, and subsequently dolomitized in its upper-to-middle sections, with a superimposed 4 m-thick red paleosol. We also propose that this unit is not coeval in age or origin with the Long Point limestone on the Coconino Plateau, and that the presence of a complex calcrete-dolocrete-paleosol alters previous interpretations associated with this unit. Evidence for a calcrete-paleosol origin, beyond the West Water Formation's lack of fossils, includes: its predominantly micritic calcite-palygorskite composition; its textures characteristic of valley and pedogenic calcrete deposits (as exhibited by thin section, SEM, and TEM analyses); and its association with a relatively thick overlying red paleosol that also contains abundant palygorskite. Stable carbon and oxygen isotope values from carbonate cements are also within the range expected of a near-surface calcrete. Carbonate minerals within the calcrete-dolocrete were precipitated at or near the water table in a valley setting due to evaporation and/or CO 2 degassing in a semi-arid to arid environment of deposition. High 87 Sr/ 86 Sr values within the calcrete were inherited from groundwater infiltrating through Music Mountain Formation arkosic sediments, which were derived from a Precambrian source terrane to the south and southwest. No absolute ages exist for the Music Mountain Formation and West Water Formation in the Milkweed and West Water paleocanyons; these sediments could range in age from the Late Cretaceous to the latest Eocene-earliest Oligocene, and may record the Eocene-Oligocene Transition in the Grand Canyon area.

This paper deals with the Middle Triassic-to-earliest Jurassic evaporite sedimentation in the epicontinental, eastern Iberian platform. This deposition occurred under extensional regime during the westwards migration of the Neotethys Ocean at the start of the Pangea break-up. Although attention is focused on the evaporitic episodes recorded in the Epicontinental (Germanic) Triassic of the platform, the evaporite units in the carbonatic Alpine Triassic are also considered. In the Epicontinental Triassic, up to six evaporitic episodes, which alternated with three carbonatic episodes and a siliciclastic one, occurred between the Anisian and the Lower Hettangian. The evaporitic episodes may be divided into two groups. The stratigraphic units of the older group have similar characteristics in salinity and facies, and were formed in chloride-rich, evaporitic mudflats. In the younger group, the salinity and depositional features display considerable differences and the environments evolved from evaporitic mudflats to extensive salterns. The different evolutive trends in the evaporites of the two groups suggest major re-structuration of the platform after the sedimentation of the siliciclastic units of the middle Keuper (Carnian Humide Episode). Progressive marine influence in the assemblage of the six evaporitic episodes is deduced from the changing nature of the evaporites and their host sediment. All the evaporite units accumulated as transgressive and highstand systems tracts. The close relationship between evaporite units and thick accumulation suggests that the structural control played a major role in the sedimentation. In the Alpine Triassic, the presence of evaporites interbedded in the allochthonous carbonate units is documented. Lateral correlation of the evaporite units of the Epicontinental and the Alpine types of Triassic allows us to reconstruct the facies continuum across the original Iberian platform. Such a west-to-east transect illustrates the palaeogeography, structural evolution, and major depositional controls in the platform during the period under study. The deduced evaporitic pattern could be applied to other Triassic platforms which acted as epeiric seaways for the westward advance of the Neotethys.

This paper provides a high-resolution temperature reconstruction for the last Millennium from Lake Atnsjøen, SE Norway (61°52′31″N, 10°10′37″E). The sedimentary record reveals strong influence of the large-scale global climate patterns on the local climate in southern part of Eastern Norway. We reconstructed mean July air temperature using Chironomidae-based transfer function and fossil Chironomidae assemblages. The reconstruction was supported by a selection of climate-sensitive geochemical and paleoecological sedimentary proxies of terrestrial and aquatic origin, including Cladocera, pollen and macrofossils. Presented results revealed that summer temperatures were 1–2 °C warmer than the mean Millennial temperatures during the 11th, 13th, 15th and 20th centuries and 1–2 °C lower during the 12th, 14th, 17th–18th centuries. A persistent cold period, the Little Ice Age (LIA), occurred between 1550 and 1800 CE, was interrupted by a short warming at 1650 CE. The recognized regional climate fluctuations during the last Millennium affected the lake and its catchment, of which the strongest impact was caused by the LIA cooling. During the LIA the catchment vegetation was impacted by climate deterioration and the lake productivity reached its lowest level during the last Millennium. The current temperature reconstruction is in agreement with a previous continental scale temperature reconstruction for Europe. From obtained results it emerges that during the LIA the climate of western Scandinavia has been dictated by the atmospheric patterns originating from the North Atlantic. peerReviewed

Wrinkle structures are microbially induced sedimentary structures (MISS) formed by cyanobacteria and are common in pre-Cambrian and Cambrian siltstones and sandstones but are otherwise rare in the Phanerozoic geological record. This paper reports the first discovery of Mesozoic wrinkle structures from Sweden. These are preserved in fine-grained and organic-rich heterolithic strata of the Lower Jurassic (Hettangian) Höganäs Formation in Skåne, southern Sweden. The strata formed in a low-energy, shallowsubtidal setting in themarginal parts of the Danish rift-basin. Palynological analyses of fine-grained sandstones hosting the wrinkle structures show that the local terrestrial environment probably consisted of a wetland hosting ferns, cypress and the extinct conifer family Cheirolepidaceae. Palynostratigraphy indicates a Hettangian age, stillwithin the floral recovery phase following the end-Triassic mass extinction event. The finding of wrinkle structures is significant as the presence of microbial mats in the shallow subtidal zone, (in a deeper setting compared to where modern epibenthic microbial mats grow) suggests decreased benthic biodiversity and suppressed grazing in shallow marine environments in the early aftermath of the end-Triassic mass extinction event. 2015-04264 Utgör mass-utdöenden en driftkraft för evolutionen? Studier från krita-paleogengränsen Swedish Research Council 349-2007-8705 Lund University Carbon Cycle Centre (LUCCI) UNESCO-IUGS-IGCP Project 632

Evaluating and understanding bio-environmental relationships at different spatial and temporal scales is important for accurately assessing marine productivity in relation to oceanographic conditions in changing Arctic ecosystems. In this paper, we compare four different bio-environmental datasets, in order to shed new light on the complex marine ecosystem of the Baffin Bay-Labrador Sea region, as well as the historical links between environmental changes and the ecosystem. Satellite dataset was used to describe the regional distribution of chlorophyll a, sea ice concentration (SIC), sea surface temperature (SST) and sea surface salinity (SSS). Chlorophyll a data were also analysed together with shrimp assessment dataset to examine the relationship between marine pelagic productivity and bottom feeders off the Greenland coast. A microfossil dataset (diatom valves) from 57 surface sediment stations was used to describe diatom concentration and diversity across the study region. It was also used in combination with satellite data from the same sites to analyse species-environment relationships and develop a diatom-based transfer function for reconstructing past changes in SIC, SST and SSS. Subsequently, we applied the diatom transfer function on three short sediment cores from off SW and W Greenland spanning the last few centuries. A monitoring dataset of sea ice observations and instrumental measurements of water temperature and salinity, together with atmospheric data (air temperature and wind conditions) from Greenland, were used to develop a more complete picture of 20th and 21st century changes in ocean-climate conditions. Our comparative analyses show clear spatial distribution patterns of marine phytoplankton and identify key ecological groups linked to oceanic conditions. In addition, we find a significant correlation between the different trophic levels, culminating in a ‘productivity boom’ in 2001 CE. On a longer temporal scale, the transfer function reconstructions reveal a good correlation with the satellite, monitoring and observational trends, as well as a consistent, long-term decrease in sea ice linked to ocean-climate variability.

This paper reviews quantitative biostratigraphic data from 101 petroleum exploration wells from the Malay, Sarawak and Sabah basins, and places the stratigraphy of each area into a precise chronostratigraphic framework comprising 41 transgressive-regressive depositional packages which are fully defined here. Each package is ‘fingerprinted’ by foraminiferal, nannofossil and palynological index fossils, and then tied to the global pattern of glacio-eustatic sea level and climate changes based on the global δ18O and δ13C datasets used to calibrate the geological timescale. The result is a tightly constrained chronostratigraphic framework that is applicable from deep to shallow water and is of high accuracy. It is concluded that there is a sedimentation ‘pulsebeat’ across Southeast Asia, independent of local and regional tectonics, driven by patterns of global climate change. For the Oligocene and Miocene, Antarctic glaciation is the key driver, whereas the Pliocene cycles are mainly driven by the expansion and contraction of Northern Hemisphere glaciers. The new chronostratigraphic framework allows unconformities across Malaysia to be better characterised, and the different classification schemes of seismic “Groups” in Malay and Penyu basins, “Cycles” in offshore Sarawak and “Stages” in offshore western Sabah to be correlated. Also, with a clear understanding of the effect of fluctuating sea levels on the stratigraphy of the region, it is easier to make firm judgments regarding the effect of tectonics. The study also characterises systems tracts from shelf to basin floor using biostatigraphic assemblages, which should help in ground-truthing the architecture of depositional sequences in the region based on seismic. The new framework is proposed as an alternative to the outdated TB scheme of Haq et al. (1988) , widely used to interpret depositional cycles across Sarawak and Sabah.

Mortality curves are a valuable tool to study taphonomy and to infer population structure in ancient communities; however, they rely on the precise determination of ontogenetic ages of individual animals, which is often uncertain for fragmentary and isolated fossil remains. In this paper, we develop a new protocol to construct mortality curves for fossil rhinocerotids using both tooth rows and isolated teeth, based on dental wear. We tested and calibrated this protocol using 29 skulls and 18 jaws of extant rhinoceroses (Diceros bicornis, Rhinoceros sondaicus, and R. unicornis). We then applied it to four extinct rhinocerotid species from the late early Miocene locality of Beon 1 of Montreal-du-Gers, SW France: the teleoceratines Brachypotherium brachypus and Prosantorhinus douvillei, the basal rhinocerotine Plesiaceratherium mirallesi, and the early elasmotheriine Hispanotherium beonense. Findings allow us to estimate population structures of these rhinocerotids, based on the percentage of juveniles, subadults and adults. The mortality curves of Beon 1 rhinocerotids reveal several major periods of vulnerability: birth, weaning, sexual maturity, and middle-late adulthood. When compared to extant populations (D. bicornis, Ceratotherium simum, and R. unicornis) and other ancient case studies (Miocene of USA, Pleistocene of Southeast Asia and France), mortality rate curves from Beon 1 are similar in early and late life; however, they lack the increased socially-driven mortality that is observed between 25 and 50% of the potential lifespan in some populations of D. bicornis and in the Miocene teleoceratine Teleoceras proterum. The population structures of Pr. douvillei, Pl. mirallesi, and H. beonense are close to those of extant populations of D. bicornis. In contrast, adult specimens of B. brachypus are overrepresented at Beon 1, similarly to Aphelops malacorhinus at Love Bone Bed (USA), probably due to taphonomical bias. It is important to note that considering isolated or associated teeth alone results in significant differences in mortality curves and population structures at Beon 1, hence both samples should be studied.

International audience; This paper presents the first continuous pollen record from the southern Namib Desert spanning the last 50,000 years. Obtained from rock hyrax middens found near the town of Pella, South Africa, these data are used to reconstruct vegetation change and quantitative estimates of temperature and aridity. Results indicate that the last glacial period was characterised by increased water availability at the site relative to the Holocene. Changes in temperature and potential evapotranspiration appear to have played a significant role in determining the hydrologic balance. The record can be considered in two sections: 1) the last glacial period, when low temperatures favoured the development of more mesic Nama-Karoo vegetation at the site, with periods of increased humidity concurrent with increased coastal upwelling, both responding to lower global/regional temperatures; and 2) the Holocene, during which time high temperatures and potential evapotranspiration resulted in increased aridity and an expansion of the Desert Biome. During this latter period, increases in upwelling intensity created drier conditions at the site. Considered in the context of discussions of forcing mechanisms of regional climate change and environmental dynamics, the results from Pella stand in clear contrast with many inferences of terrestrial environmental change derived from regional marine records. Observations of a strong precessional signal and interpretations of increased humidity during phases of high local summer insolation in the marine records are not consistent with the data from Pella. Similarly, while high percentages of Restionaceae pollen has been observed in marine sediments during the last glacial period, they do not exceed 1% of the assemblage from Pella, indicating that no significant expansion of the Fynbos Biome has occurred during the last 50,000 years. These findings pose interesting questions regarding the nature of environmental change in southwestern Africa, and the significance of the diverse records that have been obtained from the region.

This paper is not subject to U.S. copyright. The definitive version was published in Palaeogeography, Palaeoclimatology, Palaeoecology 451 (2016): 73-83, doi:10.1016/j.palaeo.2016.03.018.

Glacial sediment is an important paleoclimatological and paleoenvironmental archive. In the Mediterranean region most of the Quaternary glaciers were hosted in carbonate mountains. Diagenetical processes in carbonate sediments tend to impact preservation of glacial features and complicate the establishment of accurate chronologies. This paper presents a sedimentological study of a paleoglacier hosted in the carbonate Velebit Mountain, Croatia. Three carbonate tills were studied in order to evaluate their depositional environments and the diagenetical processes that affect them. The tills were selected from lateral moraines of different glacial stages of the paleoglacier and they are interpreted as lodgement and melt-out tills. Diagenetical processes such as cementation, dissolution and increase in organic content were enhanced by the percolation of water through the sediment and the propagation of rootlets. This research demonstrates the importance of understanding the diagenetical processes affecting carbonate tills after their sedimentation. Studies like this are an essential research stage prior to conducting geochronological and paleoclimatological interpretations based on paleoglaciers in carbonate regions.

The paper describes Late Jurassic–Early Cretaceous seep carbonate boulders from the Russian Arctic island of Novaya Zemlya, collected in 1875 by A.E. Nordenskiold during his expedition to Siberia. The carbonates are significantly depleted in heavy carbon isotopes (δ13C values as low as ca. − 40‰) and show textures typical for carbonates formed under the influence of hydrocarbons, such as fibrous carbonate cements and corrosion cavities. The rocks contain index fossils of Late Oxfordian–Early Kimmeridgian, Late Tithonian (Jurassic) and latest Berriasian–Early Valanginian (Cretaceous) age. The fossil fauna is species rich and dominated by molluscs, with subordinate brachiopods, echinoderms, foraminifera, serpulids and ostracods. Most of the species, including two chemosymbiotic bivalve species, likely belong to the ‘background’ fauna. Only a species of a hokkaidoconchid gastropod, and a possible abyssochrysoid gastropod, can be interpreted as restricted to the seep environment. Other seep faunas with similar taxonomic structure are suggestive of rather shallow water settings, but in case of Novaya Zemlya seep faunas such structure might result also from high northern latitude.

Two new 40Ar/39Ar ages (*) and previously published K/Ar ages of basaltic pillow lava flows are coeval with closely-related fossiliferous marine layers, allowing us to establish the beginning (5.8; 5.0; 4.8 Ma at Ajui, Fuerteventura Island and 4.8 ± 0.03 Ma (2σ)* at Tamaraceite) and a middle stage (4.20 ± 0.18 Ma (2σ)* at La Esfinge in Gran Canaria Island) of Early Pliocene marine deposits in the Canary Islands. Here the presence of tropicopolitan fossils (Megaselachus megalodon, Janthina typica) suggests the influence of a possible Central American Circumtropical Current during the Pliocene and in the North Atlantic basin. The presence of both Janthina typica and the Argonauta argo also indicate the occurrence of tropical storms in the area of the Canary Islands around that time. In addition, the pillow lava flow at La Esfinge overlies a submarine pyroclastic layer containing Ostrea offreti that was preserved in its life position, a fossil from the terminal Miocene and commonly found on the south eastern Iberian Peninsula. At La Cruz on Fuerteventura Island, a dune formed above marine deposits lies beneath a palaeosol and a basaltic lava flow that was K/Ar dated at 2.9 Ma. Near El Marmol in Gran Canaria the corresponding palaeosol lies between lava flows K/Ar dated at 3 Ma. Based on these observations, we argue in this paper that the first appearance of the Canary Current, the eastern boundary current of the North Atlantic sub-tropical gyre, occurred between 4.2 Ma and 2.9 Ma ago. This was followed by a major sea level drop (of about 40 m) and the formation of a first fossil-bearing palaeosol which indicate that major climate change that took place around 2.95–2.82 Ma.

Volcanic islands are unique contexts to analyze the controls on calcrete development in settings with varied relief, climate and vegetation, and lacking carbonate host rocks. This paper discusses the formation of Quaternary calcrete profiles in Gran Canaria volcanic Island, under direct influence of the SAL (Saharian Air Layer). Calcrete profiles are multi-storey and composed of prismatic, massive, laminar, pisolithic, ooid-bearing, sandy mudstones with rhizoliths and brecciated horizons. Host rocks include basalts, siliceous mudstones, volcanic sands and gravels and bioclastic-rich sands. Carbonate is mostly calcite but some dolomite occurs in massive horizons. The main microfabrics include laminated micrite, fine crystalline dolomite, desiccated micrite, micrite-clay groundmass, oriented Mg-rich clays, peloids, spherulites and coated grains. δ13C varies from −3.26 to −9.18‰ VPDB and δ18O from +0.86 to −3.24‰ VPDB. The 87Sr/86Sr ratios are between 0.707504 and 0.708860, indicating that calcium was mostly supplied from the CaCO3-rich aeolian dust coming from the Sahara Desert. Calcrete profiles are mostly pedogenic with roots and microorganisms enabling carbonate precipitation within the soils. The correlation trend of δ13C and δ18O points to a climate control on precipitation, with the heavier isotope values in the horizons containing dolomite. Sedimentation rates interplayed with calcrete formation processes and erosion to outline the profiles/horizons. Amalgamated laminar horizons formed when the rate of calcrete formation was higher than sedimentation and erosion, whereas areas or periods with relatively higher sedimentation allowed the separation of calcrete horizons. The direction of the winds supplying aeolian dust, and the varied relief, vegetation and climate favored better development of calcretes in the relatively arid and lowland areas of the eastern side of the island. Our study shows that calcretes contain the record of the paleoenvironmental controls that operated in volcanic islands with no previous carbonate substrates.

The lower Miocene Santa Cruz Formation (dated to ~18–16 Ma) of Southern Patagonia, Argentina, preserves rich vertebrate faunas, which are representative of communities that existed prior to the Great American Biotic Interchange (GABI). Some previous researchers have hypothesized that these pre-GABI faunas had a low richness of mammalian carnivores (an impoverished predator guild), while others argue for a predator/prey ratio similar to those of recent communities. In this paper, we analyze faunas from the lower part of the Santa Cruz Formation (FL 1–7) using a methodology that allows us to quantify (i) the meat resources that were available to the secondary consumers of the palaeocommunity; and (ii) the competition intensity for these resources. In our modeling, we considered different scenarios related to meat consumption, including the possibility that several taxa had a scavenging behavior, and also differences in mortality rates between young and adult prey. Our results provide estimates of the nutritional requirements from the predator/scavenger guild under maximum and minimum quantities of meat offered by the prey community, which indicate the presence of a well-balanced palaeocommunity. Moreover, the competition indices point to a relatively high level of competition for prey of small-to-medium size, although competition for resources from large mammal prey was rather low. This suggests that the predator/scavenger guild was not impoverished, although there were insufficient carnivore species to fully consume the megaherbivore biomass.

This paper presents pollen analyses and radiocarbon dating on Crocuta coprolites from Las Ventanas (LV) and Carihuela (Car) Caves in southern Spain (Granada), with the aim of reconstructing the environmental conditions of these hominin sites. The LV coprolites are radiocarbon dated from c. 37,890 to 6980 cal yr BP, and the Car coprolites from c. 31,063 to 7861 cal yr BP. Overall, the palaeoecological scenario inferred from both coprolite series display similar patterns, with Pinus, Poaceae, and Artemisia as dominant during the full Pleistocene, and an important contribution of Quercus in the most recently dated coprolite samples. While the palynology is consistent with results of former investigations on the past environments in the region as obtained from other deposits (peat bogs, cave infills), the Late Glacial and Holocene chronology of several coprolites in both sites is in conflict with the generally accepted timing of extinction of Crocuta in western Europe. A discussion on the taphonomical processes and potential sources of carbon contamination of the radiocarbon samples is provided. The correlation between pollen from coprolites and from sedimentary records, and the paucity of the fossil bone record suggests nevertheless, that a late survival of Crocuta in southern Spain should not be categorically discarded.

Geographically isolated insular species face energetic restrictions and commonly evolve adaptations that distinguish them from their mainland ancestors. During the Pleistocene, several Mediterranean islands were inhabited by now extinct Hippopotamidae. They underwent diverse changes in locomotion, dentition and body size. Based on these differences, it is supposed that they occupied different ecological niches depending on their respective faunal complexes and available resources. In this paper, we assess the paleoecology of dwarfed hippopotami from Crete, Malta, Sicily and Cyprus using a novel dental multiproxy approach. We applied dental topography analysis (SAGA-GIS) to measure the mean slope of the dental occlusal surface, mirroring dietary adaptations, as well as 3D surface texture analysis (3DST) to quantify the surface of occlusal wear facets, which correlate with dietary abrasiveness. Low slope values were found in the larger, more hypsodont hippopotami, whilst the smaller Phanourios minor displayed the highest occlusal relief with large compression basins. Since Hippopotamus pentlandi exhibited lower mean slope values than the larger, more hypsodont Hippopotamus amphibius, we conclude that lower occlusal reliefs reflect adaptations to lower diet quality and arid environments, which are characteristic of freshwater-limited island habitats. The 3DST analysis revealed distinct ecological niches for the investigated insular hippos. Hippopotamus creutzburgi exhibited enamel surface textures analogous to those of Hippopotamus amphibius, a fresh grass grazer, thus confirming a semiaquatic lifestyle at the upland lake at Katharo, Crete. Hippopotamus pentlandi was bound to a similar niche to the extant form, probably due to the mainland character of its fauna, but experienced more dust intake. Hippopotamus melitensis had to cope with high ingestion of abrasives, seemingly on account of a more generalistic diet in its resource-limited and small habitat. Results point to either Phanourios minor broadening its dietary niche in its almost competition-free habitat, or suggest a dietary shift following a climatic change. The adopted multiproxy approach proved to be useful in identifying dental adaptations and individual foraging strategies linked to energetically restricted habitats, and therefore contributes to a better understanding of basic evolutionary and ecological principles.

The Paraná Basin, the largest basin in South America, received glacially derived sediments during the Late Palaeozoic Ice Age (LPIA) of the Gondwana supercontinent. Despite the importance of this basin for understanding the continental development of the Gondwana glaciation, and the fact that ca. 95% of this basin is not exposed at the surface, few attempts have been made to connect the exposed glacial strata to the subsurface record. In this paper, exposures of glacial cycles in the Upper Itararé Group in Santa Catarina State, southern Brazil, are analyzed, locally correlated and then linked to the three major glacial cycles previously described from subsurface studies along the basin. Together study areas (Doutor Pedrinho and Vidal Ramos) record five, partially comparable shorter glacial subcycles (relative to the major glacial cycles). These series comprise coarse-grained subaqueous outwash deposits, turbidite sand sheets, marine shales, and diamictites, the latter mostly derived from delta slope failure and ensuing resedimentation. In addition to sedimentological and genetic stratigraphic description and analysis, preliminary age determination based on the palynological content is also presented. Besides, a regional correlation of the described succession to the subsurface record is proposed based on well logs and core information. All the palynomorph associations identified from the exposed successions, which represent the upper third part of the Itararé Group, are related to the Subzone Protohaploxypinus goraiensis, base of the Vittatina costabilis Zone. This zone and correlated ones along the Gondwana are considered Early Permian in age. However, a first isotopic age recently obtained for the upper Itararé Group and published elsewhere is considered within a regional stratigraphic framework once it leads to new insights in terms of the LPIA time span recorded in the Paraná Basin. Fil: Valdez Buso, Victoria. University of Aberdeen; Reino Unido Fil: Danielski Aquino, Carolina. Universidade do Vale do Rio Dos Sinos. Programa de Pós-Graduação em Geologia; Brasil Fil: Gomes Paim, Paulo Sérgio. Universidade do Vale do Rio Dos Sinos. Programa de Pós-Graduação em Geologia; Brasil Fil: Alves de Souza, Paulo. Universidade Federal do Rio Grande do Sul; Brasil Fil: Mori, Ana Louisa. Universidade Federal do Rio Grande do Sul; Brasil Fil: Fallgatter, Claus. University of Aberdeen; Reino Unido Fil: Milana, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina Fil: Kneller, Benjamin. University of Aberdeen; Reino Unido

The Last Interglacial Period (LIP) is often regarded as a good analogue for potential climatic conditions under predicted global warming scenarios. Despite this, there is still debate over the nature, duration and frequency of climatic changes during this period. One particularly contentious issue has been the apparent evidence of climatic instability identified in many marine cores but seemingly lacking from many terrestrial archives, especially within the Arctic, a key region for global climate change research. In this paper, geochemical records from Lake El'gygytgyn, north-eastern Russia, are used to infer past climatic changes during the LIP from within the high Arctic. With a sampling resolution of ~ 20–~ 90 years, these records offer the potential for detailed, high-resolution palaeoclimate reconstruction. This study shows that the LIP commenced in central Chukotka ~ 129 thousand years ago (ka), with the warmest climatic conditions occurring between ~ 128 and 127 ka before being interrupted by a short-lived cold reversal. Mild climatic conditions then persisted until ~ 122 ka when a marked reduction in the sedimentation rate suggests a decrease in precipitation. A further climatic deterioration at ~ 118 ka marks the return to glacial conditions. This study highlights the value of incorporating several geochemical proxies when inferring past climatic conditions, thus providing the potential to identify signals related to environmental change within the catchment. We also demonstrate the importance of considering how changes in sedimentation rate influence proxy records, in order to develop robust palaeoenvironmental reconstructions.

In this paper we present a paleoceanographic reconstruction of the southwestern South Atlantic for the past 13 kyr based on faunal and isotopic analysis of planktonic foraminifera from a high-resolution core retrieved at the South Brazil Bight continental slope. Our record indicates that oceanographic changes in the southwestern South Atlantic during the onset of the Holocene were comparable in strength to those that occurred during the Younger Dryas. Full interglacial conditions started abruptly after 8.2 kyr BP with a sharp change in faunal composition and surface hydrography (SST and SSS). Part of the observed events may be explained in terms of changes in thermohaline circulation while the other part suggests a dominant role of winds. Our data indicate that during the Early Holocene upwelling was significantly strengthened in the South Brazil Bight promoting high productivity and preventing the establishment of the typically interglacial menardiiform species. In general terms, oceanographic changes recorded by core KF02 occurred in synchrony with Antarctica's climate.

This paper presents the first quantitative study of the Early Jurassic recovery of ammonoids after the end-Triassic mass extinction based on detailed U–Pb ID-TIMS (isotope dilution thermal ionization mass spectrometry) geochronology from ash bed zircons placed within a clear phylogenetical and biochronological framework at the subzonal and species level. This study was triggered by the discovery of a rich Peruvian succession of ammonites, deposited concomitantly with an unusually large number of ash beds. Two major phases of rediversification are observed during the Psiloceras spelae and Angulaticeras zones that correspond to positive peaks in the δ13Corg curve, providing a possible link between biodiversity and the global carbon cycle. In the case of the post-extinction recovery, the development of the earliest Hettangian ammonites occurs within the genus Psiloceras, which begins with the occurrence of P. spelae and then explodes into worldwide development of smooth psiloceratids of the Psiloceras planorbis group s.l. This rapid biodiversification likely occurred less than 100 ka after the end-Triassic crisis; the genus Psiloceras occupied all the possible ecological niches worldwide, from the Pacific deep waters to the NW European shallow deposits and also in some rare Tethyan occurrences like at Germig in Tibet. This global dispersion allowed the differentiation of the group in several major phyla, the Schlotheimiidae, Discamphiceratinae, Arietitidae and Lytocerataceae, which were the roots of all other Jurassic and Cretaceous ammonites.

In this paper, we present a chronostratigraphic calibration of the shallow benthic zones (SBZs) of larger foraminifera during Lutetian times based on new magnetostratigraphic data (Isuela section) and two new densely sampled biostratigraphic sections (Isuela and Gabardiella). These sections are located in the External Sierras (Southern Pyrenees) and represent an ideal location to avoid previous chronostratigraphic problems. 1) They belong to a shallow carbonate shelf environment with abundant larger foraminifera, which ensure the reliability of SBZ data. 2) The time span covers almost the entire Lutetian interval. 3) The profiles are sufficiently long to establish trustworthy local scales, both the SBZs (520 m and 760 m in Isuela and Gabardiella respectively) and the paleomagnetic local polarity sequence (LPS) (520 m). 4) The excellent outcropping conditions also permit a detailed paleomagnetic and biostratigraphic sampling to be performed. The LPS at the Isuela section was built after sampling every 2.6 m. In total, more than 359 samples were thermal (244) and alternating field (115) demagnetized. Characteristic remanent magnetization (ChRM) usually dropped at 560 °C. Only 43% the samples (359 demagnetizations) gave reliable directions (high quality) for the LPS. A further short section (Gas line) was also cored (38 samples in 90 m) to obtain more detailed data for the upper part of the section. At the Isuela section, the results allow three pairs of trustable magnetozones to be assembled within the Lutetian. A further 255 samples were taken for biostratigraphic purposes, 55 sites at the Isuela and 52 at the Gabardiella sections being determinant. This density enabled a thorough study of changes in fossil associations to be performed. Assuming a constant accumulation rate within the chron boundaries, absolute ages have been estimated for the biostratigraphic boundaries. Combining all these data allows the previous calibration of SBZ during Lutetian times in the geological time scale to be refined. In particular, with this new data, we identify the SBZ 13/SBZ 14 boundary at 44.46 Ma reaching C20r; a boundary interval spanning from SBZ 14 to SBZ 15 (41.36 and 42.45 Ma) is found within C20n and C19n; and, finally, the top of SBZ 15 can be accurately located at 41.12 Ma (C19r), Unidad de Zaragoza, Instituto Geológico y Minero de España, España, Departamento de Ciencias de la Tierra, Universidad de Zaragoza, España, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Universitat de Barcelona, España, Consultant Geologists, Unidad de Tres Cantos, Instituto Geológico y Minero de España, España

This paper is not subject to U.S. copyright. The definitive version was published in Palaeogeography, Palaeoclimatology, Palaeoecology 469 (2017): 159-160, doi:10.1016/j.palaeo.2016.11.028.

A quantitative biochronological study by Cody et al. (2008) integrates comprehensive diatom biostratigraphy, magnetostratigraphy, and tephrostratigraphy from 32 Neogene sections around the Southern Ocean and Antarctic continental margin. A recent method, known as Constrained Optimization (CONOP), which can be viewed as a multidimensional version of graphic correlation, is applied to that very interesting database. The goal of the present paper is to discuss some theoretical aspects of quantitative biochronology and to compare the constrained optimization with the deterministic method called Unitary Associations (UAM), a graph theoretical model. We illustrate the fact that the UAM is an extremely powerful and unique theory allowing an in-depth analysis of the internal conflicting inter-taxon stratigraphic relationships, inherent to any complex biostratigraphical database.

article i nfo This paper presents an updated, extensive review of glacier fluctuations during the past 1000 years in the extratropical Andes of South America between ca. 17° and 55°S. Given the variety of environmental conditions and evidence available for glacier fluctuations across this wide latitudinal range, regional accounts are given for the Desert Andes (∼17°-31°S), the Andes of central Chile and Argentina (31°-36°S), and the North (36°-45°S) and South (45°-55°S) Patagonian Andes. The techniques, dating limitations, and interpretations of the glacier records along this transect are also discussed. Information on glacier fluctuations in the Desert Andes is limited to the 20th century. Documentation on past glacier variations is more abundant in the Central Chilean-Argentinean Andes, but the number of chronologies dealing with glacier fluctuations prior to the 1900s is also limited. Most records indicate that glaciers were generally more extensive prior to the 20th century, with dates of maximum expansion ranging from the 16th to the 19th centuries. The number and extent of glaciers increase significantly in the Patagonian region, where the evidence available for dating glacier variations during the past centuries is more abundant and the dating control for glacier events is generally better than in the northern parts of the study area. For some Patagonian glaciers, maximum Little Ice Age (LIA) or post-LIA advances have been precisely dated by dendro- geomorphological determinations or in situ measurements. However, for most sites, the evidence available is still preliminary and there is considerable variability in the extent and timing of events related to the maximum LIA expansion identified in most areas between the 16th and 19th centuries. Evidence is starting to appear at a growing number of sites for glacier advances during the first half of the past millennium. These events were generally less extensive than the LIA maximum pulses. Despite the occurrence of several post- LIA readvances over the past 100-110 years, most areas in the Andes of extratropical South America have experienced a general pattern of glacier recession and significant ice mass losses. The differences in the glacier histories observed at local and regional scales probably reflect the inherent limitations associated with the glacier records and/or the dating techniques used in each case together with the varying dominance of precipitation, temperature and other climatic and non-climatic factors on glacier mass balance and glacier dynamics. These differences indicate that the late Holocene glacier history of southern South America is more complex than commonly assumed. The evidence discussed in this study highlights not only the immense potential for glaciological studies of this region but also a significant need for an increased number of detailed, well-dated records of glacier fluctuations.

article i nfo In South America, the arid and semiarid subtropical regions through the Atacama Desert and north-central Chile between 19° and 32°S are currently a gap in the tree-ring chronology network. Only a short tree-ring chronology has been published for this vast region and little is known about the suitability of many woody species for tree-ring analysis and dendroclimatology. In this paper we present the first detailed analysis of the climate responses and influences of the El Nino-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) on the tree-rings of three species new to dendrochronology and that typically occur at high elevations in the Andes of central and north-central Chile. Three well-replicated tree-ring chronologies of Kageneckia angustifolia, Proustia cuneifolia and Fabiana imbricata are compared with century-long regional records of precipitation and temperature, and with the N3.4 SSTand PDO indices in both time and frequency- domains using correlation and wavelet analysis. The radial growth of these species is controlled by winter precipitation and is also positively correlated with temperature during most of the rainy season from April to September (autumn-spring). The regional climate as well as tree growth is strongly modulated by ENSO and ENSO-like conditions in the equatorial Pacific at both interannual and interdecadal timescales. The decadal and interdecadal variability is not correlated with PDO and appears to be related to the Interdecadal Pacific Oscillation (IPO), a Pacific-wide ENSO-like mode of climate variability. Despite their relatively short lifespans, these three new species have a high potential for dendrochronological and dendroclimatic studies in the semiarid region of Chile over the last two centuries.

“One of the major obsessions of many early workers, to the mid-1900s, was the application of uniformitarian principles to deposi-tional models for black shales“ (Arthur and Sageman, 1994).The purpose of this overview of organic-carbon(OC)-rich marinesediments is to provide a brief but current summary of the historicaldevelopments, principle concepts, and remaining challenges in inte-grated sapropel and black shale research. As such, it provides asubstantive introduction to the Special Issue of Palaeogeography,Palaeoclimatology, Palaeoecology on “Organic Carbon Rich Sedimentsthrough the Phanerozoic: Processes, Progress, and Perspectives”.Giventhis focused scope, the overview does not aim to be comprehensive orcomplete but to provide a solid setting for the fourteen individualresearch papers that constitute this Special Issue and two previousspecial issues (Meyers and Negri, 2003; Negri et al., 2006)thatcoverresearch aspects complementary to this one. Like the individualcontributions, this introduction and overview is organized intoCenozoic, Mesozoic, and Palaeozoic units. The Cenozoic and PalaeozoicunitsaredeliberatelylargerthantheMesozoicunit,acknowledgingthatmuch ground on Mesozoic black shale is already covered in the twoprevious special issues. Because the Late Cenozoic sapropels of theMediterraneanBasinhavebeenextensivelystudied,understandinghowthese near-modern analogs of ancient black shales were depositedprovidesagoodfoundationforunderstandinghowtheoldersequencesmayhaveevolved.Incontrast,becausefarlessisgenerallyknownabouttheblackshalesofthePalaeozoicthancomparableOC-richsequencesofeither the Cenozoic or the Mesozoic, a more comprehensive summaryand comparison of the more ancient sequences is particularly appro-priate to the theme of this Special Issue.1. IntroductionSediments rich in organic carbon are restricted to small areas alongcontinental margins in the modern ocean and have rarely accumulatedduringtheCenozoic,yetorganic-rich sediments werewidely depositedduring multiple intervals of Mesozoic–Palaeozoic time and even earlierduringtheProterozoic–Archean.Globalmarinedepositsdocumentthatepisodes of accumulation of OC-rich sediments occurred in differentregions and at different times. These episodes were linked to climaticandpalaeoceanographicperturbationsthat resulted inmassive fluctua-tions in hydrologic and nutrient cycles and in oceanchemistryand thatrecurred throughout geologic time. However, the paucity of survivingPalaeozoic and earlier black shale sections makes it difficult toimpossible to recognize the internal structure of global events that arecommon inyounger OC-rich sedimentary sequences.Asunderlinedbelow,themarinesectionsinmanylocalitiesconsistof intercalated carbonates and shales that may grade into purecarbonate or black shale sedimentation, often reflecting shallowing/

In this paper two different Italian late Messinian lago-mare ostracod assemblages, dominated mainly by extinct Paratethyan species, have been analysed by means of Detrended Correspondence Analysis (DCA). The obtained plots have been compared and, with the help of the limited autoecological data on similar living species and geochemical data on the sediments in which they were included, the autoecology and synecology of the lago-mare assemblages have been inferred. In particular, it seems reasonable to suppose that: 1) assemblages made only by pointed candonids are typical of rather deep (possibly less than one hundred meters of depth) and freshwater/oligohaline environments; 2) assemblages mainly composed of Leptocytheridae point to shallow (probably few tens of meters of depth) and mesohaline waters; 3) diversified and even assemblages made both by pointed candonids and Leptocytheridae are common in rather deep (less than one hundred meters of depth) but oligo/low mesohaline environments; 4) Caspiocypris seems rather tolerant of brackish salinities, but prefers shallow environments; 5) Tyrrhenocythere could be an indicator of shallow and fresh/oligohaline waters. 6) Cyprideis is an indicator of shallow waters but can withstand a very wide salinity range.

South-central Chile is one of the most geodynamically active areas in the world, characterized by frequent volcanic eruptions and numerous earthquakes, which are both recorded in lake sediments. In Lago Icalma (39°S), long piston and short gravity coring, as well as 3.5 kHz high-resolution seismic profiling, have been carried out in order to study the Holocene sedimentary infill of the lake, with a special focus on earthquake-triggered deposits. Macroscopic description of sediment cores and detailed grain-size analyses allow us to identify four types of seismically-induced deposits, or “seismites”: slump deposits, chaotic deposits, turbidites s.s. and homogenites. Homogenites are characterized by the occurrence of three distinct units on grain-size profiles (i.e., a coarse base, a thick homogeneous unit topped by a thin layer of very fine sediment) and by the typical distribution of the grain-size parameters in a skewness–sorting diagram, while turbidites s.s. are characterized by a continuous fining-upward trend. Radiocarbon, 210Pb dating, and tephrochronology allow us to demonstrate that the regional seismotectonic activity was probably very high between 2200 and 3000 cal years BP as well as between 7000 and 8000 cal years BP and that none of the historically documented earthquakes has triggered a seismite in Lago Icalma. The most recent seismite recognized in the sediments of Lago Icalma is a slump deposit dated at 1100 ± 100 AD, i.e., older than the period covered by historical records. The remarkable record of seismites between 2200 and 3000 cal years BP is probably influenced by a major eruption of Sollipulli volcano at 3000 cal years BP, which has rejuvenated the stock of terrigenous particles available for erosion, by depositing a thick layer of pumices all over the watershed of Lago Icalma and by clearing the vegetation covering the volcanic ash soils. This paper demonstrates that the record of seismically-triggered deposits in lake sediments is not only controlled by the intensity of the triggering earthquake and the occurrence of unstable sediment along the lake slopes but also by the presence of particles available for erosion/remobilisation in the watershed.

16 pages, 2 tables, 7 figures., A multiproxy geochemical study of nine sapropel layers from ODP Hole 964A, ODP Leg 160 in the eastern Mediterranean spanning the Pliocene–Holocene time interval provides new insights into the evolution of sapropel deposition. Paleoenvironmental proxies were used for reconstruction of productivity (Ba derived from marine barite), oxygen conditions (trace metal ratios) and sedimentary regime (clay minerals, detrital elements). These proxies reveal a significant increase in river runoff relative to decreasing aeolian input during sapropel deposition over the whole time interval. Ba excess supports the argument that a significant increase in export productivity is the main triggering mechanism for sapropel deposition, although preservation also played an important role. Furthermore, major differences exist in depositional conditions, including both oxygenation and productivity since the Pliocene. Productivity fluctuated substantially and was higher during the Pliocene and Pleistocene than during the Holocene; at the same time decreasing oxygen availability parallels the enhanced productivity. Dysoxic to anoxic conditions appear to coincide with marine productivity maxima, thus suggesting that oxygen depletion may be linked to greater consumption rather than restricted circulation. This correspondence supports the hypothesis that productivity fluctuations resulting from climate oscillations were the main cause of enhanced organic matter contents and also a main controlling factor for reduced oxygen availability., This work was supported by Projects REN 2003- 09130 and CGL2006-13327-C04-04/CLI (“Ministerio de Educación y Ciencia”), Project RNM 432 and Research Group RNM 179 (“Junta de Andalucía”).We also thank Project CSD2006-00041 Topoberia. We are grateful to the Ocean Drilling Program for providing us with the samples used in this study as well as to the ODP Core Repository (Bremen, Germany) for assistance with sampling. Analyses were performed at the “Centro de Intrumentacion Cientifica” (University of Granada), and at the Stable Isotope Lab (Green Earth Science Building, Stanford University). We are also very grateful to David A. Mucciarone for carrying out the analysis of the samples at Stanford University. Finally we are indebted to Dr. P. Meyer for such a detailed and constructive review that significantly improved the final version of this paper. We are also grateful to one anonymous reviewer who also provided valuable input. Finally, we are very grateful to the Editor, Dr. Corrège, for an exhaustive and helpful review and valuable comments.