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I analyzed phytoliths from soil profiles on San Cristóbal Island in the Galápagos Islands to determine whether historical human impact and recent vegetation dynamics are visible in the phytolith record. I extracted phytoliths from soil samples taken from four test pits located at the village, an abandoned field, a forest, and an active agricultural field - all located within the former El Progreso plantation (AD 1860–1920). Changes in the ratio of tree to grass phytoliths with depth in all four samples suggest changes in vegetation composition from forest to open vegetation dominated by grasses, which reflects the removal of forest with colonization and the first permanent human occupation of the archipelago in the middle 19th century. This paper shows that the changes in vegetation brought about by colonization and land clearing for plantations are documented in the soil phytoliths record, and suggests that phytoliths can be used as an indicator of past vegetation change in future work on the historical ecology of the Galápagos archipelago. [ABSTRACT FROM AUTHOR]

This paper examines a glacial diamictite-bearing succession from the upper Itararé Group (Taciba Formation) in eastern Paraná Basin, Brazil. The object of study provides the opportunity to investigate in detail the late stages of glacial sedimentation during the Late Paleozoic Ice Age (LPIA) in this sector of SW Gondwana, with implications for glacial cyclicity and regional paleo-ice flow reconstructions. Sedimentology, geological mapping and palynological analysis allowed the recognition of four facies associations, comprising subaqueous outwash, mass-transport, tide-influenced delta-front, and tide-influenced delta plain deposits. The succession records at least two episodes of ice-margin advance and retreat into a marine-influenced environment and can be placed in the earliest Permian based on the palynomorph assemblage. Cross stratification in outwash facies and deltaic deposits indicate sediment transport to the SW, the same revealed by deformational structures in mass-transport diamictites derived from downslope resedimentation of glaciomarine sediments during deglaciation. A glacial source to NE is therefore indicated and is in agreement with paleo-ice flow directions obtained from previously studied localities to the north. This north-derived early Permian glaciation contrasts with glacial sources to the SE recognized in the lower and middle intervals of the Itararé Group. The scenario suggests a geometric reconfiguration of the Paraná Basin during the LPIA and the migration of ice centers with time during the Late Paleozoic Ice Age in SW Gondwana. [ABSTRACT FROM AUTHOR]

The population history of the Adélie penguin ( Pygoscelis adeliae ) and its response to climatic and environmental changes have been widely studied in maritime Antarctica and several glacial refugia of Adélie penguins were dated back to the Last Glacial Maximum. However, the process of colony expansion during the subsequent glacial-interglacial transition was less well-documented. In this paper, we investigate an ornithogenic core from Vestfold Hills, East Antarctica, to improve knowledge of postglacial penguin colonization. Local deglaciation occurred around 15.6 kyr BP, based on a coarse-grained detrital layer, a date that is earlier than most of those reported in other studies from the same region. Geochemical analysis of the core suggests penguins started colonizing the northern Vestfold Hills around 14.6 kyr BP, the oldest geological record in East Antarctica on penguin occupation, and their population exhibited a broadly increasing trend thereafter. The population expanded at approximately 6740 yr BP, in the mid-Holocene, which corresponds to a local climatic optimum. Although this inference is based on population changes of local sub-colonies, it corresponds well to reconstructions of regional climate change, and changes in the penguin population based on genetic studies. From a consideration of the results of previous studies of the occupation history of sea birds following deglaciation in the Arctic, as well as other parts of Antarctica, we propose that sea birds colonized the emerging ice-free areas shortly after local glacier retreat. Over geological time-scales, the availability of breeding habitat is a key factor controlling the population size and activity range of Antarctic Adélie penguins. [ABSTRACT FROM AUTHOR]

The Middle and Upper Jurassic stage of evolution of the anaptychus-type ammonoid jaw apparatus is relatively poorly known due to a small number of findings and uncertainty of their taxonomic position. All previously found anaptychi of this age are preserved either in flattened and dissolved shells or separately from ammonoid conchs. Rhynchaptychus-type jaws were still hitherto unknown from Jurassic deposits. In this paper we describe three-dimensionally preserved ammonoid lower jaws from the Bajocian/Bathonian boundary (Middle Jurassic) beds of Dagestan, Russia. These findings demonstrate a wide variety of their shape and structure. One specimen, consisting only of organic matter which is considered as anaptychus sensu stricto , is located in situ in the body chamber of Lytoceras ( Dinolytoceras ) zhivagoi (Besnosov). Three specimens which likely belonged to any Phylloceratiadae ( Adabofoloceras , Holcophylloceras , or Pseudophylloceras which are presented in the ammonoid assemblage) contain prominent calcareous conchorhynchs, and the outer organic lamellae of these jaws were initially covered with a thin calcareous layer. The last lower jaw, probably from Nannolytocera s, has also a small calcareous conchorhynch in its tip despite a lack of coating. These findings are the first direct evidence of the existence of rhynchaptychus-type lower jaws in the Middle Jurassic. A variety in the shape and structure of the studied lower jaws indicates a variation in the mode of life and feeding behavior of Middle Jurassic ammonoids. [ABSTRACT FROM AUTHOR]

Traditional methods of palaeontogical fieldwork often involve costly and inefficient searching for suitable fossil-bearing sites. The advent of digital spatial data offers an opportunity to improve fieldwork search efficiency. In this paper, we develop a model that identifies potential fossil localities at the reconnaissance stage of prospecting using a criterion of present-day environmental suitability for fossil discovery. This model employs techniques from analytical biology, Geographical Information Systems (GIS), and remote sensing. The model is designed to be flexible with no limit on the number of variables and can use a variety of data types (both continuous and categorical) by means of a principle coordinate analysis (PCO). We tested the model on outcrops of the Elliot Formation (Upper Triassic–Lower Jurassic) in the Free State, South Africa. Our model correctly predicted 95% of the known occurrences and reduced the potential prospective area from approximately 2300 km 2 of mapped total outcrop to 597 km 2 of prospectable outcrop. Initial field testing in 2015 identified two new sites based on model output. [ABSTRACT FROM AUTHOR]

Many mangrove wetland systems in deltaic environments are negatively affected by massive sedimentation from river inflows. In this paper we use the example of the Save River delta to assess the palaeogeographic distribution of mangrove wetlands and to analyze their dynamics. To track past occurrences of mangrove wetlands in the study area we have integrated sedimentological data with siliceous microfossil analysis combined with AMS radiocarbon and OSL dating. The results show a fine-grained deposit with an approximate thickness of 2 m, present at different sampling sites. In the upper deltaic plain, the deposit is interbedded between sand layers, while in the lower deltaic plain the deposit occupies the uppermost stratigraphic position. In most of the sampling sites the deposit shows a succession with brackish-marine diatoms at the bottom of the sequence while the upper part shows only scattered occurrences. Based on sedimentological and microfossil characteristics we have interpreted the layer to represent a mangrove wetland deposit. The development of the deposit in the study area is suggested to have been initiated around 3100 cal. yr BP, induced by sea-level rise. Thereafter, the development followed the combined effect of a sea-level fall and delta progradation processes. In some areas, particularly in the proximal part of the delta, the mangrove deposit has developed progressively on top of the delta-front. From around 1300 years ago (OSL) onwards, massive alluvial sedimentation impacted the mangrove ecosystem. However, the retreat of mangrove wetland coincided with a regional fall of sea level. At the edges of the alluvial deposit, the current mangrove ecosystem has reclaimed the habitat in some sectors where gully erosion has exposed the once extinct mangrove habitat. [ABSTRACT FROM AUTHOR]

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 Rusophycu s 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. [ABSTRACT FROM AUTHOR]

The island of Zakynthos is one of the most seismically active areas in the Mediterranean region because it is located very close to the convergent boundary between the African and Eurasian plates. Its evolution during the Holocene has been influenced by tectonic activity, catastrophic events and relative sea level changes. The scope of the present paper is to examine the Holocene palaeoenvironmental changes of the coastal areas of Zakynthos Island using a multidisciplinary approach, combining sedimentological and palaeontological data with 14 C and OSL dating from four cores of a maximum depth of ~ 30 m. The integrated results reveal that sea level and tectonic activity have brought significant modifications in the coastal geomorphic settings of the island during the past ~ 10,000 yr B.P. The depositional environments and the palaeontological biofacies document four main geomorphological evolutionary stages of the island. We identified fully marine and lagoonal deposits with marine influence (before 4100 yr B.P.), as well as brackish and freshwater limnic depositional environments (around 4100 yr B.P. to present). The interpretation of our data indicates that Zakynthos island was separated into two main parts before the middle Neolithic period (around 7500 yr B.P.) with Vasilikos peninsula in the SE being isolated from the main island. The fact that Zakynthos Island was a divided Mediterranean island for a significant period of time in its prehistory is of great importance to understand better the archaeological landscapes of Zakynthos and the other Ionian Islands. [ABSTRACT FROM AUTHOR]

Research on the dynamics of body-size changes in varied water depths can provide important insights into the evolution of palaeoenvironments through time. This paper attempts to investigate how the body sizes of two most commonly found chonetid brachiopod species in the uppermost Permian in South China varied with palaeo-bathymetry. The result shows that there is a broadly negative correlation between the latest Permian brachiopod body size and water depth. There is no simple singular variable that could explain this correlation because bathymetry is correlated, either linearly or nonlinearly, to food availability, redox condition and habitat temperature, as well as substrate conditions. Overall, we found that both oxygen and food availability played a more important role in controlling the differences of body sizes, and specifically several depressed factors (low food availability, anoxia, or abnormal temperature) have compounded and caused small body sizes in deeper waters during the latest Permian. We propose that the brachiopod miniaturization during the Permian-Triassic crisis in South China was collectively driven by anoxia, food restriction and high temperature. [ABSTRACT FROM AUTHOR]

The calcareous nannofossil Ceratolithus acutus (= C. armatus ) is an important species associated with the final flooding that ended the Messinian Salinity Crisis in the Mediterranean. We emphasize its robust identifying features and stratigraphic value in the global ocean. This species is particularly useful in recognising and constraining the Messinian–Zanclean boundary in the Mediterranean, as evidenced by reports from 75 localities and 20 references in addition to our own papers. Our emphasis is prompted by the assessment of Stoica et al. (2016) that Ceratolithus acutus is a “dubious” species with its lowest occurrence an “unreliable” biostratigraphic event. Such assessments by non-specialists, especially when “supported” by selective referencing of the literature warrant an explanation. [ABSTRACT FROM AUTHOR]

Zhucheng, located in eastern Shandong Province, China, is well-known for its abundant Early Cretaceous dinosaur footprints and Late Cretaceous dinosaur bone fossils. Recently, Lockley et al. (2015) presented a sketch study on the Huanglonggou tracksite in the Zhucheng area, and critically commented on our paper (H. Xu et al., 2013), which conducted a detailed and comprehensive study of the tracksite. Here, we demonstrate that some of their assumptions and comments on our work are subjective and incorrect. Tracks at the Huanglonggou tracksite, including a dominant theropod (large theropod, Grallator yangi / Paragrallator , Corpulentapus lilasia ), and subordinate sauropod, suspected ornithopod, and turtle tracks were preserved in the Yangjiazhuang Formation with estimated ages of 129 to 122 Ma, rather than in the Longwangzhuang Formation as proposed by Lockley and his associates. Contrary to Lockley et al. (2015), our mapping of the Huanglonggou tracksite exhibits the previous work by Li et al. (2011) and focuses on the 50 well-preserved trackways and their orientations. Based on the stride length to footprint size index diagram and the Grallator–Anchisauripus–Eubrontes (GAE) plexus, our statistical constraints on the three species of theropods are better than those of Lockley et al. (2015). Lockley argued that tracks at the site were preserved on at least five levels, of which the majority on level 4 were of excellent preservation. In fact, the tracks identified throughout the site have been from only one level. The false appearance of multiple levels is interpreted as the result of sedimentation at the shoreline and differential excavation of the tracksite. [ABSTRACT FROM AUTHOR]

The early Aptian oceanic anoxic event (OAE 1a) is well known in the western Tethys, the North Atlantic and the Pacific Ocean, but has not been reported in the eastern Tethys to date. In this paper, we present bulk organic carbon isotope data and ammonite biostratigraphy of a lower Aptian succession from the Gucuo area (southern Tibet). These findings document the occurrence of the OAE 1a for the first time from the eastern Tethys. The studied sequence can be attributed to the D. forbesi and D. deshayesi ammonite zones of the lower Aptian. The δ 13 C org data can be correlated with published early Aptian carbon isotope records from the western Tethys and the Pacific. A distinctive negative carbon isotope excursion of 2.4‰ in the upper part of the section corresponds to segment C3 of the OAE 1a, and the following positive excursion correlates to segment C4. The absolute values of the carbon isotope ratio in the Gucuo area are higher than those of known sections in the western Tethys and equatorial Pacific. We suggest that diagenetic alteration is the major cause of the higher absolute values in the Gucuo area. [ABSTRACT FROM AUTHOR]

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 (δ 18 O) 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 (R 2 = 0.68 to 0.93; p < 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. vulgata can be used for the reconstruction of paleoclimate and the season of shell collection. [ABSTRACT FROM AUTHOR]

Geochemical signatures from biogenic carbonates are being increasingly employed as palaeoenvironmental proxies. In turn, many of these proxy archives including mollusc shells, corals, and otoliths have periodic growth structures, which allow the reconstruction of chronologically constrained records of palaeoenvironmental variability at unparalleled high temporal resolution. Studying the growth and chemistry of these periodic growth structures is known as sclerochronology. Biogenic hard parts accumulate in geological or archaeological deposits, and can be directly dated using radiometric and racemisation methods. They therefore offer the opportunity for high-resolution palaeoenvironmental reconstructions across many time intervals, all over the globe. Such data are important for several reasons: (1) understanding past climate and environmental change provides a means of contextualising current and future climate change and ecological disturbance; (2) high-resolution palaeoenvironmental records are essential for constraining, testing and validating global and regional numerical climate models; (3) palaeoenvironmental records from biogenic carbonates can provide an environmental framework from which to understand the behavioural changes and interactions of peoples with their environment. However, inter and intra-species differences in growth rate, physiology, and environmental response can cause variations in the chemical profiles of biogenic carbonates. Before geochemical data is employed for palaeoenvironmental reconstructions, it is thus necessary to examine modern specimens of the target species, or related taxa, to understand how geochemical variations are influenced by local environmental conditions, kinetic and vital effects. This allows the generation of quantitative and more reliable proxy records of environmental change. This special issue brings together the latest research on palaeoenvironmental proxy development and validation in biogenic carbonates. It includes studies on marine, freshwater and estuarine organisms (molluscs, corals and echinoderms), and on traditional as well as novel geochemical proxies. The papers presented here include in situ field calibration studies, laboratory growth experiments as well as methodological studies into the effects of sampling and pre-treatment. The geographical scope is broad, encompassing both the northern and southern hemispheres including South Africa, South America, Australia, Asia, the Mediterranean Sea and the North Atlantic. [ABSTRACT FROM AUTHOR]

This paper presents the Miocene squirrels of the Linxia Basin in Gansu Province, and a paleoenvironmental and palaeoecological analysis based on the remains collected recently by screen-washing nine localities of early to late Miocene age. The assemblages contain 12 sciurid species (nine genera, three subfamilies), including squirrels with different adaptations, predominantly ground squirrels and chipmunks. Our analysis suggests that Miocene squirrels in Linxia reflect a relatively dry climate and open shrub-steppe environment, and favorable dispersal across Eurasia. The Linxia Miocene squirrels show close taxonomic composition with contemporary faunas known from the Mongol-Xinjiang highland and adjacent regions, implying that northern China represents a single biotic province with uniform paleoenvironment. In addition, the Linxia squirrels are quite different from those found in Yunnan in southern China, which are dominantly tree and flying squirrels that suggest a humid forest biotope. The differences in distribution indicate that Miocene squirrel faunas of China showed distinct provinciality and latitudinal ecological variation. Already in the Miocene we see evidence for predecessors of the present-day Palearctic and Oriental zoogeographic provinces of North and South China. • Rich Miocene Linxia Basin squirrel assemblages show distinctive adaptions. • Preferred habitat and ecology indicate open versus forested environments. • Miocene squirrels across China indicate zoogeographic province precursors. [ABSTRACT FROM AUTHOR]

The Kumaun region of India in the northwestern Himalaya experiences complex rainfall patterns, receiving precipitation both during the summer monsoon (June to September) as well as during winter months dominated by westerlies (October to March). In this paper, we present a multi-proxy palaeoclimate record spanning the last ∼1500 years from Tadag Taal, an intermontane lake in Kumaun, India. Our dataset (stable isotope ratios, grain size, trace element ratios) suggests the occurrence of four long-term precipitation cycles of high and low rainfall coinciding with the Dark Ages Cold Period (DACP, ∼475–850 CE), Medieval Climate Anomaly (MCA ∼900–1300 CE), Little Ice Age (LIA, ∼1450–1800 CE) and Current Warm Period (CWP, ∼1850 CE to Present). We infer multi-decadal to centennial-scale shifts in the Indian summer monsoon co-varying with changes in El Niño-Southern Oscillation (ENSO) activity superimposed by changes in solar insolation. To correlate our time-series from the northwestern Himalaya with the Core Monsoon Zone and understand coherency in precipitation between the two regions, we applied the Wavelength Coherency Test. Our data suggest wet conditions during the early phase of the LIA (∼1450–1640 CE) and dry conditions in the later phase of the LIA from ∼1640–1800 CE. The wet conditions in the early LIA were perhaps driven by increased winter precipitation. This is in contrast to Central India that witnessed dry conditions during the entire duration of the LIA. This study thus suggests that monsoon strength was different during earlier and later phase of the LIA. Further, the LIA did not witness uniform climate variability through its duration as has been reported in some European and Chinese proxy records. • Study of proxy record from Tadag Taal lake, northwestern Himalaya since CE 475. • Both dry and wet events have been reported during the MCA and LIA. • The early part of LIA (∼1450–1640 CE) was wet and later LIA (∼1640–1800 CE) was dry. • During the MCA, C 3 -type vegetation was predominant. [ABSTRACT FROM AUTHOR]

Fossil bovids are key components of the Neogene mammal faunas in Eurasia, showing high diversity and rapid rates of evolution, with important implications for biostratigraphy and understanding past climate change. The Linxia Basin (Gansu Province, China) contains rich Miocene to Early Pleistocene bovid assemblages that provide an opportunity to study the evolution of this group. This paper reviews the fossil record of bovids in the Linxia Basin, which comprises more than 20 genera within seven tribes, spanning nine stratigraphic horizons and distributed across 43 fossil localities. Findings show that the diversity of fossil bovids in the Linxia Basin increased dramatically from the Early to Late Miocene but fell suddenly at the end of the Late Miocene before reaching a second peak in the Early Pleistocene. The Late Miocene mammal assemblages from the Linxia Basin may indicate somewhat younger age than previously thought based on fossil bovid comparisons. With diverse species and rich material, the bovids of the Linxia Basin present an excellent opportunity for further studies on morphology and adaptations within the group. • Linxia fossil bovids from 9 fossiliferous layers comprise over 20 genera (7 tribes). • The Linxia Dashengou Fauna shares similar bovids with Lamagou and Bahe. • Yangjiashan Fauna shares bovids with the Hipparion faunas of Baode and Qingyang. • There is chronological overlap of some faunas. [ABSTRACT FROM AUTHOR]

This study aims to quantify the intensity and diversity of plant-insect associations observed in the fossil assemblage of Gelinden, Limburg, Belgium. The site yields a rich collection of well-preserved plant remains, mainly leaves, from a Paleocene European temperate forest. The 780 specimens presented here were scanned using standardized morphotype systems for any trace of damage. This raw data was then used to quantify the intensity and diversity of interactions in the Gelinden flora. This material showed an impressive richness of interactions, contrasting with the poor North American sites covering the period that followed the Cretaceous-Paleogene extinction. Both hosts and interaction types observed at Gelinden are two to three times more abundant than in most American floras, in raw numbers and leaf area affected. This is coherent with what has been observed in the few other studies conducted in Europe, South America and Antarctica, pointing toward more regionalized effects of the extinction than previously assumed based on American findings. This greater richness implies that these sites were either less affected or quicker to recover from the Cretaceous/Paleogene extinction, questioning its global impact, at least on the lower levels of the food web, as discussed in the following paper. • We provide quantitative data on plant-insect interactions observed in the Gelinden flora. • One of the few such study on a European locality. • Higher richness compared to similar age North American localities. • Supporting conclusion drawn from previous studies in France and South America. • Recovery from the K-Pg extinction was probably more regionalised than previously assumed. [ABSTRACT FROM AUTHOR]

Identification of Holocene climate events, their temporal and spatial characteristics, and their causal mechanisms are important for understanding past climate systems with implications for interpreting ancient cultural transformations. In this paper, we analyse globally-distributed, high-resolution climate proxy records from 58 sites to develop a comprehensive understanding of climate change around 7.2 ka BP. Analysis of the data compilation, which comprises records from lake sediments, one loess section, speleothems, marine sediments, and ice cores, show that the climate event is manifested as a weakening of the Asian summer monsoon and a strengthening of the South American summer monsoon. Climate change also involves dramatic cooling and wetter conditions in north-central Europe, widespread aridity across the Africa and west-south North America, contrasting patterns of precipitation variability throughout the Mediterranean, and notable cooling over the polar regions, suggesting that this is a global climate event. A close correspondence between the 7.2 ka event and the timing of solar irradiance minima, strong volcanic eruptions, meltwater flux into the North Atlantic Ocean, and an orbitally-induced decrease in summer solar insolation suggests a possible causal link with these phenomena. We suggest that climate anomalies around 7.2 ka BP may be specifically explained as a response to southward migration of the Intertropical Convergence Zone, onset of an increasingly El Niño-like state, reinforcement of the westerlies, and slowing of the Atlantic Meridional Overturning Circulation (AMOC). • The 7.2 ka event is well represented in 58 paleoclimatic records from the global. • Varying climatic responses are evidenced in different regions during 7.6–7.0 ka BP. • The 7.2 ka event arise of the atmosphere–ocean–land feedback in response to four forcing factors. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the Holocene record of extreme flood events in the upper Minjiang River valley of the eastern Tibetan Plateau, China. Slackwater deposits (SWDs), the fine-grained sediments of palaeofloods, were identified within debris flow deposits at a tributary mouth and in channel expansions along the bedrock gorge. Eight palaeoflood SWDs were dated to between 6.0 ± 0.9 ka and 4.6 ± 0.9 ka using optically-stimulated luminescence analysis in combination with the minimum age model and represent at least two phases of palaeoflood events. The palaeoflood history in the upper Minjiang River Valley is consistent with the record of the mid-Holocene flood events in the mainstream of the Yangtze River. These mid-Holocene extreme flood events were closely related to strong ENSO activity and variability of the monsoon climate in the eastern Tibetan Plateau. In our study area, minimum palaeoflood discharges were estimated as 6500–7800 m3/s by the step-backwater method. These estimated discharges are less than the values inferred for the outburst flood that occurred in the upper Minjiang River Valley in 1933. Flood-inundation maps show that palaeoflood SWDs were deposited in low-velocity backwater zones. Our palaeoflood reconstructions are important for improving regional records of maximum flood and help to develop risk analysis for rare flood events. • Sedimentary characteristics of palaeoflood records in complex environment were identified. • Palaeoflood discharges were estimated to be 6500–7800 m3/s at the three study sites. • Palaeoflood results redefine the envelope curve of the regional maximum floods. • Response of mid-Holocene (6.0–4.6 ka) extreme flood events to climate variability. • Palaeoflood reconstructions help to develop risk analysis for rare flood events. [ABSTRACT FROM AUTHOR]

In recent decades, southernmost South America (50–56° S) has experienced marked climate change (regional warming, decreased precipitation, reduced snow cover, and increased frequency of heat waves) related to variations in atmospheric circulation over varied timescales. In this paper, we develop oxygen isotopes from tree-ring cellulose (δ18O TRC) as a proxy for climate and atmospheric circulation in order to extend the regional meteorological record to deeper time intervals. Our work focuses on Nothofagus forests in two areas: (i) deciduous N. pumilio forest in the steppe transition zone near Punta Arenas and (ii) humid evergreen N. betuloides forest in the Navarino Island region. To investigate the potential for reconstructing palaeoclimate, δ18O TRC variations were correlated with local climate parameters as well as regional (Amundsen Sea Low, ASL) and hemispheric (Antarctic Oscillation, AAO) atmospheric circulation modes for the last 60 years. N. betuloides δ18O TRC variations show an overall positive trend, indicating isotopic enrichment over the study period, whereas no trend is recorded for the N. pumilio record. The strongest relationships with climate, together with the widest spatial representativeness, occur in the N. betuloides chronology during the growing season (spring to austral summer) and extend spatially from mid to high latitudes. In contrast, the sensitivity of the records is limited to summer months, and spatial correlations are much more limited. In addition, the N. betuloides record shows greater potential for reconstructing local climate features such as soil water (r = − 0.76), wind speed (r = 0.69), and precipitation (r = − 0.66), as well as regional (ASL, r = − 0.80) and hemispheric (AAO, r = 0.77) patterns of extratropical atmospheric circulation. Overall, we conclude that the N. betuloides record represents the most valuable tree-ring climate proxy for southernmost South America over past centuries. • Two annual oxygen isotope (δ18O) records from Nothofagus tree rings in southern South America are established. • Strong climatic signals in δ18O from Nothofagus betuloides and N. pumilio are related to local and regional climatic variations. • Differences in climatic sensitivity among δ18O records are related to species-specific responses and site specificities. • δ18O TRC record of N. betuloides from Navarino Island shows strong relationships with soil water content (r = − 0.76) with regional (ASL, r = − 0.80) and hemispheric (AAO, r = 0.77) extratropical atmospheric circulation. • δ18O TRC records from N. betuloides forests show high potential to reconstruct climate variations during the last 400–500 years. [ABSTRACT FROM AUTHOR]

Non-articulated trimerellides, one minor group among the largest brachiopods, are commonly found in massive monospecific accumulations in Ordovician and Silurian rocks. In this paper, all species of the family Trimerellidae are listed for the first time, and some of them are discussed. They appeared in the Sandbian and became extinct in the Ludlow with an apex of diversification observed, at generic level, during the Katian and at species level, during the Wenlock. Platforms and vaults are the diagnostic morphological characteristics of the trimerellids, and constitute the important basis for generic classification. Individuals with highly raised platforms and deep vaults first appeared in the middle–late Katian, but became the main morphology in the Silurian. Nineteen genera of Trimerellidae are selected in this study, and 30 characters are coded for morphospace and phylogenetic analyses. Based on the morphospace analysis by non-metric multidimensional scaling (NMDS), we have differentiated the morphological characteristics of platforms and vaults into three types (I, II and III). The results of the phylogenetic analysis show a tendency for platforms and vaults to become more prominent in younger genera (from Type I to III). Trimerellids are divided into four morphological groups based on the differences of shell shape or life style. This evolutionary trend of platforms and vaults is reflected in all four morphological groups. • Trimerellids diversified at generic level in Katian and species level in Wenlock. • The platforms and vaults of trimerellids are more prominent in younger species. • Morphospace of trimerellids detected by NMDS can be divided into three groups. • All known trimerellids distributed within 30 degrees north and south palaeolatitude. [ABSTRACT FROM AUTHOR]

The marine shelves of passive margins receive huge amount of terrestrial organic carbon (OC) exported from adjacent terrestrial ecosystems. Long-term sequestration of terrestrial OC into marine sediments plays an important role in the global carbon cycle on a range of timescales. However, our knowledge of factors affecting the fate of terrestrial OC in continental-marginal settings is incomplete, with ongoing debates regarding rates of degradation during transport and burial. In this paper, we employ analyses of total OC and its stable isotope (δ13C), terrestrial biomarkers and mineral surface area in sediment core 39-A obtained from mud-rich regions of the inner shelf of the East China Sea to investigate terrestrial OC burial history over the last 3000 years. Analysis of terrestrial lipid biomarker and terrestrial OC calculated based on a δ13C-binary mixing model shows increasing trends since ∼1400 yr BP, accompanied by a synchronous increase of terrestrial OC preservation rate. By compiling terrestrial OC records from mud-rich regions of the East China Sea inner shelf, we propose that the most reasonable explanation is the intensification of the East Asian Winter Monsoon. This resulted in a strengthening of coastal currents, which accelerated lateral transport speed (thereby shortening oxygen exposure time) of Changjiang (Yangtze River)-derived terrestrial OC towards the deposition site, resulting in greater terrestrial OC preservation. Moreover, we also found delayed responses of terrestrial OC burial to the East Asian Winter Monsoon in the middle and southern part of the Min-Zhe coastal mud region, implying that the transport of terrestrial OC towards this region took place on a centennial-time scale. Our study sheds new light on mechanisms controlling terrestrial OC transport and burial processes in a typical passive marginal sea. • Sedimentary OC in the MZCM was a mixture of Changjiang-derived OC and marine OC. • Terrestrial OC content and burial efficiency increased since ∼1400 yr BP. • The EAWM-driven coastal current determined terrestrial OC burial efficiency. • Transport of terrestrial OC along the MZCM took place on centennial-time scale. [ABSTRACT FROM AUTHOR]

Biogeographic analysis has been applied on the globe- or orogen-scale tectonic evolution. The scarcity of paleobiogeographic study cases caused a debate as to the Late Paleozoic detailed accretion and convergence process of collages in the Central Asian Orogenic Belt. This contribution presents contrasting biota characteristics of the Early and Middle Devonian rugose corals in the Dananhu-Harlik Arc. By the multivariate analyses of the Early and Middle Devonian rugose coral faunas from series of the tectonic units in the Central Asian Orogenic Belt and neighboring areas, we reveal that two distinct paleobiogeographic units, namely, the Boreal and Tethyan Realms, were separated by the North Tianshan Ocean and Kalamaili Ocean in the Early and Middle Devonian, respectively. It means that the Dananhu-Harlik Arc experienced a paleobiogeographic change from the Boreal Realm in the Early Devonian to the Tethyan Realm in the Middle Devonian. Comprehensively considering the coral paleobiogeography, paleomagnetism, magmatism, provenance and distribution of ophiolites in the southwestern Central Asian Orogenic Belt, we speculate that the basal controlling factors of the Devonian coral paleobiogeographic pattern in the CAOB are the geographical isolation caused by the presence of oceanic basins, and the Mongolia and Kazakhstan Collages were separated by the North Tianshan Ocean sandwiched between the Dananhu-Harlik Arc and Central Tianshan Block during the Silurian to Early Devonian. In the Middle Devonian, the bidirectional and roll-back subduction of the North Tianshan Ocean caused the Dananhu-Harlik Arc separated from the Mongolia Collage by the Kalamaili Ocean and further moved towards the eastern Kazakhstan Collage. It caused the change of the rugose coral paleobiogeographic pattern in the southwestern Central Asian Orogenic Belt. The terminal convergence of Dananhu-Harlik Arc and Kazakhstan Collage occurred before the Latest Devonian and subsequently led to the formation of a new collage sandwiched by the Junggar-Kalamaili and South Tianshan Oceans. • This paper reports the Middle Devonian shallow-water rugose coral faunas in the Dananhu-Harlik Arc for the first time. • The analysis results clearly show where the boundary of Boreal and Tethyan Realms lay in the southwestern CAOB during the Early to Middle Devonian. • This contribution proposes a distinctive tectonic evolution model of the southwestern CAOB, based on the comprehensive consideration of paleobiogeographic recognizing and other geological evidences. • This is the first time that multivariate analyses of marine bottom invertebrates are applied to better reveal the tectonic evolution history of the CAOB. It is likely an innovative method for accretionary orogenic belt studies. [ABSTRACT FROM AUTHOR]

With the discovery of the Bozhong 19–6 large gas field in the Bohai Bay Basin, the study of lacustrine source rocks in the southwestern Bozhong Sag has garnered new interest. In this paper, 107 source rock samples of the Paleogene Shahejie Formation (Es) from the southwestern Bozhong Sag were analyzed with organic and inorganic methods and compared with other sags in the Bohai Bay Basin to reveal the depositional environment and controlling factors of organic matter enrichment during the deposition of the Es. The formation of source rocks (average total organic content = 2.76%) was subject to a combination of high organic productivity and enhanced organic preservation. Also, this was reflected by the existence of nutrient elements of P and Ba as well as other high productivity-related elements such as Cu, Zn, and Ni. The moderate Mo enrichment factor, Pr/Ph and low to moderate (C/P) org ratios were an essential part of this organic preservation. Moreover, the evidence we observed for the existence of hydrothermal activities consisted of high contents of quartz and pyrite, large positive Eu anomalies, and enrichment of elements related to hydrothermal fluids. Hydrothermal influence may lead to similarities and fluctuations in water salinity, organic productivity and preservation in the third (Es 3) and first (Es 1) members of the Es. Hydrothermal fluids may play an essential role in promoting the development of high organic productivity, stable reducing environment, and brackish water (as shown by the range of B/Ga and TS/TOC) in the lakes during the source rock deposition. This paper may provide implications for gas accumulation mechanisms and a complete set of organic and inorganic experimental data for source rock analysis in other lacustrine rift basins. • The source rocks from the Shahejie Formation (Es) were formed in brackish lakes. • The organic productivity is the main controlling factor of the source rock formation mechanisms. • The existence of hydrothermal fluids may affect environmental changes. [ABSTRACT FROM AUTHOR]

Major reorganizations in climate and tectonic regime occurred in East Asia during the Pleistocene, resulting in large-scale environmental changes. In this paper a detailed geochemical and mineralogical record of these changes is presented from a distal alluvial fan sedimentary sequence in the northern Weihe Basin. We established that, in addition to glacial-interglacial variation, there are three distinctly different units deposited over the past 1 m.y. These units are the result of variations in the overall tectonic regime in the northern Weihe Basin. Fine-grained detrital minerals were predominantly delivered during colder climatic periods, whereas evaporative minerals were dominantly deposited during the warmer, interglacial periods, probably as a result of strong seasonal contrast. This compositional variation demonstrates the importance of climate control on hinterland erosion, surface runoff, chemical weathering and evaporation. Al-normalized ratios of indicative major elements relative to average loess composition, indicate important variations in sedimentary processes, mostly related to sediment flux. Si-enrichment is an index for past flooding events, while Fe enrichment, just like K and Ti, reflects influx of clays. In contrast, Ca and Mn are strongly enriched throughout the core, associated with the authigenic precipitation of carbonates, especially during interglacial periods. The lower (~ 1000–690 ka) and upper (~ 330–0 ka) units of the core are characterized by relative intense and frequent flooding, which coincided with extensive ponding in the study area. In the middle unit (~ 690–330 ka) increased salinity levels caused by evaporation, as reflected in the high Sr/Ca ratio and dolomite abundance, led to increased carbonate precipitation. Simultaneously, the increased influx of fine sediments indicates increased clay production in the source area as a result of a more intense summer monsoon strength after 600 ka. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Artemisia and Chenopodiaceae are the two main pollen taxa in studies of lake sediments on the central and western Tibetan Plateau (TP). In this paper, we present Artemisia /Chenopodiaceae (A/C) ratios in pollen assemblages of surface sediments from 42 lakes on the central and western TP. Relationships between vegetation, climate and A/C ratio are investigated. The results show that the A/C ratio in the study region can distinguish desert from steppe vegetation. As a whole, the A/C ratio was higher than 1.2 in the steppe vegetation and lower than 1.2 in the desert vegetation zone. Statistical analysis revealed that the A/C ratio can be used as a moisture indicator on the TP. Based on the A/C ratio in pollen assemblages of sediment core TAN12-2 from Lake Tangra Yumco, we reconstructed the vegetation and climate history of the southern TP during the transitional period from the late glacial to the Holocene (17.5–10 cal kyr BP). From 17.5 to 16 cal kyr BP, desert vegetation occurred and climate was extremely dry. During 16–15 cal kyr BP, desert was replaced by steppe vegetation and climate became wetter. From 15 to 10 cal kyr BP, the lake basin of Tangra Yumco was covered by the steppe vegetation and climate tended to be more humid. Comparing our results with other lacustrine records on the TP, we found that the Indian summer monsoon (ISM) significantly affected the southern TP earlier than the northeastern TP. [ABSTRACT FROM AUTHOR]

In this paper, we synthesize sedimentological, magnetostratigraphic and paleontological data from the continental vertebrate site of Puerto de la Cadena (Murcia, SE Spain), in order to clarify its age. The study site is located on the northern edge of the Carrascoy mountain range, in the upper part of the Cigarrón Unit. The end-Messinian discontinuity has been detected at the base of this unit, which indicates it has an early Pliocene age. Abundant remains of small and large vertebrates, including rodents, lagomorphs, primates, carnivorans, perissodactyls, artiodactyls, proboscideans, testudines, squamats, and crocodiles, have been found in this area. Some of these elements are of African origin, such as Debruijnimys sp., Macaca sp., and Sivatherium cf. hendeyi , and their presence is related to the Messinian Salinity Crisis. In addition, remains found at this site verify the persistence of Crocodylia in the European record beyond the late Miocene. The association includes typical elements of the early Ruscinian terrestrial record (MN14), like Apocricetus cf. barrierei , Sivatherium , Gazella aff. baturra , and Hipparion fissurae . The Puerto de la Cadena site is located in a reversed geomagnetic chron that has been correlated with C3n.3r (from 4.997 to 4.896 Ma). According to this correlation, the MN13/MN14 boundary has a minimum age of 4.9 Ma. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]