Climatic Deterioration Research Articles

The extinction of the giant deer Megaloceros giganteus (Blumenbach): New radiocarbon evidence

The giant deer, Megaloceros giganteus, is one of the most celebrated of late Quaternary megafaunal species. Here we present new radiocarbon data on the pattern of its extinction, and compare this, on a region-by-region basis, with evidence of environmental change and human occupation. Following strict auditing criteria for the acceptance of radiocarbon dates, 51 dates are published here for the first time, bringing the total number of accepted dates for the species to 134. For western Europe, extirpation around the start of the Younger Dryas stadial is corroborated. Previous early-to mid-Holocene records for the Urals and Siberia are augmented by new dates that together provide an almost continuous radiocarbon record from the late-glacial to the mid-Holocene. Newly-rediscovered skeletal material of giant deer from the Maloarchangelsk region of European Russia has provided the latest date for the species known so far, and extends the mid-Holocene range substantially westward almost to Ukraine. The relatively narrow overall distribution of M. giganteus through its history, and direct palaeoecological evidence, demonstrate the species’ requirement for a mixed, partially open habitat providing both graze and browse. Its extirpation from western Europe remains strongly linked to deterioration of climate and productivity in the Younger Dryas, while its disappearance from more eastern areas correlates chronologically with the spread of closed forest. However, these intervals also coincide with the arrival of (probably sparse) human populations in the regions occupied by giant deer in Ireland and across Russia. The pattern of distributional changes leading to the Holocene restriction of giant deer populations strongly suggests environmental causation, but a contribution of human hunting to the extirpation of terminal populations cannot be ruled out.

‘Affective’ witnessing and testimony in contemporary environmental cinema

This article advances that through incorporating registers of affect, environmental cinema might better approximate its socially and ecologically transformative goals. A film in which this has been attempted is Fisher Stevens’s Before the Flood (2016), and it is contended here that for this reason the film holds promise despite the weakness of some of its proposed solutions to climate deterioration. An analysis of the film is offered, during which certain of Julie Doyle’s, Nathan Farrell’s and Michael Goodman’s reservations about Before the Flood are countered, drawing particularly on Anton Van der Hoven and Jill Arnott’s arguments in favour of affective cinema. Indeed, a pro-affective film-making approach finds theoretical support in the perspectives of materialist ecological feminists and African philosophers on the role of affect and emotion in being fully human. The article concludes that affect should be recuperated and strategically included within cultural products and interactions, particularly if these aim to engender significant socio-cultural change.

The Little Ice Age signature in a 700-year high-resolution chironomid record of summer temperatures in the Central Eastern Alps

Despite the fact that the Little Ice Age (LIA) is well documented for the European Alps, substantial uncertainties concerning the regional spatio-temporal patterns of temperature changes associated with the LIA still exist, especially for their eastern sector. Here we present a high-resolution (4–10 years) 700-year long mean July air temperature reconstruction based on subfossil chironomid assemblages from a remote lake in the Austrian Eastern Alps to gain further insights into the LIA climatic deterioration in the region. The record provides evidence for a prolonged period of predominantly cooler conditions during AD 1530–1920, broadly equivalent to the climatically defined LIA in Europe. The main LIA phase appears to have consisted of two cold time intervals divided by slightly warmer episodes in the second half of the 1600s. The most severe cooling occurred during the eighteenth century. The LIA temperature minimum about 1.5 °C below the long-term mean recorded in the mid-1780 s coincides with the strongest volcanic signal found in the Greenland ice cores over the past 700 years and may be, at least in part, a manifestation of cooling that followed the long-lasting AD 1783–1784 Laki eruption. A continuous warming trend is evident since ca AD 1890 (1.1 °C in 120 years). The chironomid-inferred temperatures show a clear correlation with the instrumental data and reveal a close agreement with paleotemperature evidence from regional high-elevation tree-ring chronologies. A considerable amount of the variability in the temperature record may be linked to changes in the North Atlantic Oscillation.

Trace Carbon Dioxide Capture by Metal–Organic Frameworks

Climate deterioration is closely related to the CO2 concentration in the atmosphere, which is considered one of the major environmental challenges we are facing today. It is urgent to take immediat...

Late Cenozoic palynofloras revealing significant environment and climate changes in Changbai Mountain area, NE China

The present climate in the Changbai Mountain area, NE China is warm with abundant rainfall. It is mainly affected by the wet air mass from the Sea of Japan. Local vegetation belongs to the warm temperate mixed conifer and broad-leaved forest, with a mountain cold temperate coniferous forest belt occurring at an altitude of over 1100 m. The Neogene vegetation history of this region is not yet well understood because of the lack of palaeobotanical data. Here we report a systematic palynological result of a plant-bearing diatomite sequence at Badaogou of Changbai Mountains in Jilin Province, which shows distinct vegetation and environment changes during the late Neogene. Seven palynological assemblages are recognized in the diatomite deposits from a freshly closed mine (Zones M-I and M-II), and an outcrop (Zones I–V) respectively in ascending order. Pollen data indicate a dominant woody angiosperm plants such as Ulmus, Quercus, Pterocarya and Fagus etc. at first (Zone M-I). Subsequently, gymnosperm plants mainly represented by Pinus, Tsuga, Picea and Abies show an increase (Zone M-II), and become predominant at a lowest sample in the outcrop (Zone I), distinguished by rich Picea, along with large amount of Tsuga, Pinus and Abies. Pinus increases significantly, while Picea remains higher value, and Abies and Tsuga become limited in the following assemblage (Zone II). Woody angiosperm pollen Tilia, and terrestrial herbs and shrubs including Asteraceae and Chenopodiaceae show their first sign of increase in Zone III, and become more distinguishable in Zone IV. Picea rises again in Zone V. Pollen assemblages display a successive change of vegetation between the mine (Zones M-I and M-II) and the outcrop (Zones I–V), reflecting their continuity in time. Based on the Ar–Ar dating, the outcropping deposits (Zones I–V) are the Latest Pliocene in age, approaching to the Plio-Pleistocene boundary. Consequently, pollen data in this study indicate a major turnover from the warm temperate mixed conifer and broad-leaved forest (Zones M-I and M-II) to the cold temperate coniferous forest (Zone I) during the Late Pliocene in the Changbai Mountain area. It also displays some subsequent fluctuations including the warm temperate mixed conifer and broad-leaved forest partly recovered in Zones III and IV, and decreased again in Zone V. It shows for the first time how local vegetation responses to the global climate deterioration in the Late Pliocene of NE China. The overall changing process is more or less comparable with some simultaneous vegetation changes in North China and Central Japan. The terrestrial herbs and shrubs in the assemblages are not significant comparing with other areas in North China, reflecting the influence of wet air mass from the Sea of Japan. Meanwhile, Tsuga is gradually disappearing in the upper assemblages as a result of continuous lower temperature.

Hyper-longirostry and kinematic disparity in extinct toothed whales

AbstractToothed cetacean (Odontoceti) lineages in the Miocene and Pliocene evolved rostra that are proportionally more elongate than any other aquatic mammal or reptile, living or extinct. Their similarities in cranial proportions to billfish may suggest a convergent feeding style, where the rostrum is swept through the water to hit and stun prey. Here we calculated second moment of area from rostral cross sections of these fossil odontocete taxa, as well as from extant ecological analogues, to infer variation in feeding behavior. Our results show that the extremely long rostra of extinct toothed whales vary considerably in functionally relevant measures of shape and likely exhibited a diversity of feeding behaviors, ranging from those similar to modern odontocetes to those convergent with billfish. Eustatic sea-level and temperature maxima of the Miocene likely led to changes in prey characteristics or abundance that enabled the repeated evolution of this extreme morphotype, which later went extinct during late Pliocene climatic deterioration.

A Pinus cembra L. tree-ring record for late spring to late summer temperature in the Rhaetian Alps, Italy

Ongoing climate change strongly affects high-elevation environments in the European Alps, influencing the cryosphere and the biosphere and causing widespread retreat of glaciers and changes in biomes. Nevertheless, high-elevation areas often lack long meteorological series, and global datasets cannot represent local variations well. Thus, proxy data, such as tree rings, provide information on past climatic variations from these remote sites. Although maximum latewood density (MXD) chronologies provide better temperature information than those based on tree-ring width (TRW), MXD series from the European Alps are lacking. To derive high-quality temperature information for the Rhaetian Alps, Pinus cembra L. trees sampled at approximately 2000 m a.s.l. were used to build one MXD chronology spanning from 1647 to 2015. The MXD data were significantly and highly correlated with seasonal May-September mean temperatures. The MXD chronology showed a generally positive trend since the middle of the 19th century, interrupted by short phases of climatic deterioration in the beginning of the 20th century and in the 1970s, conforming with the temperature trends. Our results underline the potential for using Pinus cembra L. MXD to reconstruct mean temperature variations, especially during the onset and latter part of the growing season, providing additional information on parts of the growing season not inferred from TRW. Future studies on MXD for this species will increase the availability of temporal and spatial data, allowing detailed climate reconstructions.

Tectono-Thermal Evolution and Morphodynamics of the Central Dronning Maud Land Mountains, East Antarctica, Based on New Thermochronological Data

The lack of preserved Mesozoic–Cenozoic sediments and structures in central Dronning Maud Land has so far limited our understanding of the post-Pan-African evolution of this important part of East Antarctica. In order to investigate the thermal evolution of the basement rocks and place constraints on landscape evolution, we present new low-temperature thermochronological data from 34 samples. Apatite fission track ages range from 280–85 Ma, while single-grain (U-Th)/He ages from apatite and zircon range from 305–15 and 420–340 Ma, respectively. Our preferred thermal history models suggest late Paleozoic–early Mesozoic peneplanation and subsequent burial by 3–6 km of Beacon sediments. The samples experienced no additional burial in the Jurassic, thus the once voluminous continental flood basalts of western Dronning Maud Land did not reach central Dronning Maud Land. Mesozoic–early Cenozoic cooling of the samples was slow. Contrary to western Dronning Maud Land, central Dronning Maud Land lacks a mid-Cretaceous cooling phase. We therefore suggest that the mid-Cretaceous cooling of western Dronning Maud Land should be attributed to the proximity to the collapse of the orogenic plateau at the Panthalassic margin of Gondwana. Cooling rates accelerated considerably with the onset of glaciation at 34 Ma, due to climate deterioration and glacial denudation of up to 2 km.

Linkage between C4 vegetation expansion and dune stabilization in the deserts of NE China during the late Quaternary

Knowledge of the role of C4 vegetation expansion in regulating dune stabilization during the late Quaternary is important for understanding the evolution of the environment and climate in the climatically-sensitive margin of the East Asian summer monsoon. However, due to the lack of both reliable vegetation records and chronological control during episodes of dune activity, the relationship between C4 vegetation expansion and dune stabilization in the deserts of NE China during the late Quaternary remains unclear. Here, we present a new regional compilation of late Quaternary stable carbon isotopic data from organic matter, together with dated records from sub-aerial sedimentary deposits in the region. Our compilation of vegetation development and dune activity in these deserts suggests that C4 vegetation expansion, with a main contribution from Chenopodiaceae, and a secondary contribution from Poaceae and Cyperaceae, may have played a critical role in dune semi-stabilization with a northwestward trend, from ∼13 to 9 ka; and dune stabilization throughout the entire study region, from ∼9 to 5 ka. In addition, during the late Holocene, intensified millet cultivation (or overgrazing) and/or climatic deterioration at ∼1.5 ka likely caused an increase in C4 vegetation abundance in the deserts of NE China, which is associated with a dune mobilization episode. In contrast, after ∼2.5 ka, decreased vegetation cover and dune mobilization in the Mu Us and Hobq deserts were likely caused by poor land-use practices and historically documented droughts. Overall, C4 vegetation expansion was the main cause of dune stabilization in these deserts during the late Quaternary.

Changes in vegetation, climate and snowfall regime since the late Pleistocene in a snowy mountainous region of central Japan

Although the most crucial factor shaping vegetation history is temperature, snowfall regime is also important in regions of heavy snow. Pollen analysis in a mire in a snowy mountainous region of central Japan revealed histories of vegetation and precipitation regimes since the latest Pleistocene. The abundance of pinaceous pollen during the latest Pleistocene indicates a subalpine regional coniferous forest and cooler conditions; moreover, sandy sediment and significant occurrence of pollen from Artemisia along with several alpine elements suggest local plant communities of poor vegetation cover in an erosive environment. The increase in Betula and Quercus subgen. Lepidobalanus pollen and the decline in pinaceous pollen in 13,550 cal. yr BP indicates climatic amelioration favourable to temperate trees, and the invasion of sedges and Reynoutria to the small basin and the onset of peat deposition suggest an increase in summer rain. The increase in Fagus crenata pollen after 11,130 cal. yr BP and onwards indicates that the present heavy snowfall regime induced by inflow of the Tsushima Current has been established since that age. The climatic amelioration delayed establishment of the heavy snowfall regime for more than 2400 years. In addition, the retreat of sedges and subsequent invasion of several species of drier habitat after 11,130 cal. yr BP indicate a drier mire condition caused by increased summer temperatures. The recovery of sedges after 3740 cal. yr BP indicates the wettest mire conditions induced by climatic deterioration. A general increasing tendency of conifers in this period supports this interpretation.

Pastoralism may have delayed the end of the green Sahara

The climate deterioration after the most recent African humid period (AHP) is a notable past example of desertification. Evidence points to a human population expansion in northern Africa prior to this, associated with the introduction of pastoralism. Here we consider the role, if any, of this population on the subsequent ecological collapse. Using a climate-vegetation model, we estimate the natural length of the most recent AHP. The model indicates that the system was most susceptible to collapse between 7 and 6 ka; at least 500 years before the observed collapse. This suggests that the inclusion of increasing elements of pastoralism was an effective adaptation to the regional environmental changes. Pastoralism also appears to have slowed the deterioration caused by orbitally-driven climate change. This supports the view that modern pastoralism is not only sustainable, but beneficial for the management of the world’s dryland environments.

First European record of Homiphoca (Phocidae: Monachinae: Lobodontini) and its bearing on the paleobiogeography of the genus

ABSTRACTMarine mammal fossils (except pinnipeds) have commonly been found in Pliocene marine siliciclastic layers of the Neogene Guadalquivir Basin in Southwest Spain. A few Neogene phocid innominate bones are known from the Western Paratethys and Western Atlantic. Here we describe a new innominate bone from the early Pliocene (5.3–3.6 Ma) of the Western Paratethys (Spain), which is typical of the subfamily Monachinae, and has a flattened ilium similar to representatives of the tribe Lobodontini, particularly Leptonychotes weddellii. Comparison with other fossil monachine innominates from North America, South America and South Africa reveals that this specimen represents the genus Homiphoca, but species classification remains premature. This is the first European record of the genus Homiphoca and has paleobiogeographic implications, questioning the geological age of the Varswater Formation ‘E’ Quarry, Langebaanweg, Cape Province of South Africa. This discovery from the eastern North Atlantic further implies a more regular transatlantic gene flow in Miocene and Pliocene times than today. We argue that during the Messinian-Zanclean crisis, monachines became isolated and retreated southward to lower latitudes, possibly due to climatic deterioration (during glacial stages) and competition from the cold-adapted phocines from the north.Abbreviations: NMNH: National Museum of Natural History, Smithsonian Institution, Washington, DC., USA; CMM: Calvert Marine Museum, Solomons, Maryland (USA); UTM: Universal Transverse Mercator Coordinate system

A high-resolution pollen record from East China reveals large climate variability near the Northgrippian-Meghalayan boundary (around 4200 years ago) exerted societal influence

The large and rapid climate change event that occurred around 4200 years ago (hereafter the 4.2-kyr event that marks the onset of the Meghalayan stage) is one of the most significant climatic anomalies in the Holocene. It may have exerted profound societal impact globally; however, its triggering mechanism remains uncertain. Here we present a high-resolution, well-dated pollen record covering this interval from the Tianluoshan archaeological site in East China. Our results show that the hydroclimatic conditions in the study area across this event strikingly resembled the regional expression of modern El Niño-Southern Oscillation (ENSO) and exhibited interdecadal ENSO-like variability from ca. 4.50 to 4.00 cal kyr BP. Also, our pollen data indicate a marked shift toward an overall increased intensity and frequency of ENSO-like climate variability from ca. 4.50 to 4.30 cal kyr BP, which was immediately followed by a decline of rice-based agriculture, providing direct evidence for the causal link between climate deterioration and the collapse of Neolithic civilization in East China some 4200 years ago. This observation is in accord with the enhanced ENSO variability reconstructed from proxy records in the tropical Pacific Ocean. As ENSO is intimately coupled with the Asian summer monsoon and the Intertropical Convergent Zone (ITCZ), we suggest that the enhanced ENSO-like climate variability may have triggered the 4.2-kyr event.

Pleistocene marine fish invasions and paleoenvironmental reconstructions in the eastern Mediterranean

Marine bioinvasions affect ecosystems in irreversible ways, creating socio-economic problems worldwide. In particular, eastern Mediterranean marine fish faunas today are significantly disturbed due to overfishing, habitat deterioration, the Lessepsian invasion, and climate change. Isolating the impact of each parameter is difficult, because pre-anthropogenic activity data are lacking. In this study, we use the paleontological record to infer the causes and mechanisms behind marine fish invasions, focusing on the Mediterranean basin, which is a restricted basin and a biological hotspot, where the effects of climatic and oceanographic changes are amplified. Therefore, the Mediterranean Sea is an ideal area to study marine biological invasions in relation to abrupt climate changes. Furthermore, we focus on the Pleistocene, which was a period of intense glacial–interglacial changes. Thus, we investigate the effect of climate changes on the fish fauna of an eastern Mediterranean shelf, by identifying the fish otoliths in the Early–Middle Pleistocene marine sediments of Rhodes (Greece). We offer a synthesis of the Mediterranean marine fish from the Tortonian until today and hypothesize on the conditions that drove marine fish distribution range shifts during the Pleistocene. We reconstruct the paleobathymetric evolution of the study areas based on fish otoliths, and we consider taphonomy in our interpretations. The Pleistocene climatic variability induced periodic and gradual replacements of fish taxa. Episodic invasions of cold-water North Atlantic mesopelagic species are correlated with intervals of climatic deterioration, specifically during marine isotope stages 50, 44, 36, 20, and 18.

Caractérisation De La Flore Et De La Végétation Ligneuse Des Terroirs Villageois De Keur Birame (Kaffrine) Et Saré Yorobana (Kolda) Au Sénégal

Vegetation in sub-Saharan countries is under heavy pressure from anthropogenic activities and climatic deterioration. This study was carried out at Keur Birame and Saré Yorobana villages, which are two edaphoclimatically contrasting localities. The aim of this study is to characterize their flora and woody vegetation. In doing so, 178 vegetation survey of 2500m² each were carried out on all two sites consisting of nine facies of vegetation. The results show a flora of the two soils of 93 species belonging to 80 genera and distributed to 33 botanical families. Among this richness, 78 species belong to Saré Yorobana and 45 species to Keur Birame. Except for regeneration rates (37.30% and 94.04%), all structural parameters studied are higher at Saré Yorobana and the similarity index (0.48) indicates that the two vegetal communities are floristically different. The ligneous stems are generally young with small diameter that hides facies imbalances due to human activities. It would require the various actors synergy to keep trees and biodiversity in the fields and terroirs.

Drainage geomorphic evolution in response to paleoclimatic changes since 12.8 ka in the eastern Kunlun Mountains, NE Qinghai-Tibetan Plateau

Investigation of the geomorphologic evolution of drainage basins can provide insight into the response of mountain-basin systems to paleoclimate fluctuations. This study investigates the evolution of geomorphic units and their connectivity, from upstream piedmont to downstream salt lake, since the late Quaternary in the Golmud River catchment of the eastern Kunlun Mountains (KLM). The study aims to elucidate the debate over linkages between: (1) landform evolution and paleoclimatic change and (2) dynamic geomorphic processes and lake evolution in the lower basin. Based on geomorphic and sedimentological observations and an optically stimulated luminescence (OSL) chronology, we show three main phases of geomorphic processes: (1) upstream piedmont alluvial fans and an alluvial delta fan at the salt lake margin have surface sediment OSL ages of 12.8–11.4 ka, suggesting a valley aggradation stage in which mass periglacial detritus were eroded and redeposited in the drainage basin; (2) incision terraces in alluvial valley fills provide ages between 11.4 and 8.8, 8.1–6.2, and 4.9–3.9 ka. Incision is ascribed to the reduction in supply of detritus owing to glacial recession and enhanced precipitation in the early to middle Holocene; and (3) widely distributed swamp sediments in the distal delta fan date to 3.2–1.8 ka, suggesting a wetter stage within the late Holocene climatic deterioration. Loess, indicative of aridity, was deposited intermittently during the middle to late Holocene. We reconstructed a wetness index, based on wetness scores of drainage geomorphic units, which is consistent with published moisture proxies. This association implies that (1) landform processes in KLM responded well to precipitation fluctuations in Indian summer monsoon (ISM) dominant regions, indicating their climatic forcing and (2) precipitation variations in the eastern KLM have been mainly controlled by ISM intensity since 12.8 ka. Linking the geomorphologic evolution of mountain-basin systems to downstream arid basin evolution shows that the periods of fluvial terrace incision (early to middle Holocene) were probably important sources of lake salt mineral enrichment. The landscape evolution patterns of mountain-basin systems in the eastern KLM offer a model for assessing the linkages between geomorphic processes, paleoclimatic changes, and lake evolution in other arid regions.

Tephrostratigraphy of paleoclimatic archives in central Mediterranean during the Bronze Age

Re-examination of central Mediterranean paleoclimate archives on tephra layers indicates that three widely dispersed tephra layers occurred during the Bronze Age, namely Agnano Mt Spina from Campi Flegrei (ca. 4.4 cal ka BP), Avellino from Somma-Vesuvius (ca. 3.9 cal ka BP), and FL from Etna (ca. 3.3 cal ka BP). Stratigraphical correlations of selected archives using these tephra layers indicate that some records have severe chronological biases, posing important limitations to the use of these archives for defining the paleoclimate conditions during the Bronze Age. Regardless of the temporal mismatches, the Agnano Mt Spina tephra layer seems to have occurred at the beginning of a centennial scale period of climatic deterioration, while the Avellino tephra layer, taking place during a wetter period, seems to mark the end of this event. The dry event bounded by the two tephra layers seems to be correlated with the so-called “4.2 event”. Instead, the FL tephra from Etna seems to herald a new climatic deterioration at ca. 3.3–3.2 cal ka BP. Although the general frame is still incomplete, these three tephra layers appear to play a fundamental role in synchronizing archives, and can lead to the definition of a detailed paleoclimatic framework of the Bronze Age in the central Mediterranean area.

Revisiting the Role of Plant Transcription Factors in the Battle against Abiotic Stress.

Owing to diverse abiotic stresses and global climate deterioration, the agricultural production worldwide is suffering serious losses. Breeding stress-resilient crops with higher quality and yield against multiple environmental stresses via application of transgenic technologies is currently the most promising approach. Deciphering molecular principles and mining stress-associate genes that govern plant responses against abiotic stresses is one of the prerequisites to develop stress-resistant crop varieties. As molecular switches in controlling stress-responsive genes expression, transcription factors (TFs) play crucial roles in regulating various abiotic stress responses. Hence, functional analysis of TFs and their interaction partners during abiotic stresses is crucial to perceive their role in diverse signaling cascades that many researchers have continued to undertake. Here, we review current developments in understanding TFs, with particular emphasis on their functions in orchestrating plant abiotic stress responses. Further, we discuss novel molecular mechanisms of their action under abiotic stress conditions. This will provide valuable information for understanding regulatory mechanisms to engineer stress-tolerant crops.

Can Pallars i Llobateres: A new hominoid-bearing locality from the late Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula)

In the Iberian Peninsula, Miocene apes (Hominoidea) are generally rare and mostly restricted to the Vallès-Penedès Basin. Here we report a new hominoid maxillary fragment with M2 from this basin. It was surface-collected in March 2017 from the site of Can Pallars i Llobateres (CPL, Sant Quirze del Vallès), where fossil apes had not been previously recorded. The locality of provenance (CPL-M), which has delivered no further fossil remains, is located very close (ca. 50 m) to previously known CPL outcrops, and not very far (ca. 500 m in NW direction) from the classical hominoid-bearing locality of Can Poncic 1. Here we describe the new fossil and, based on the size and proportions of the M2, justify its taxonomic attribution to Hispanopithecus cf. laietanus, a species previously recorded from several Vallesian sites of the Vallès-Penedès Basin. Based on the associated mammalian fauna from CPL, we also provide a biochronological dating and a paleoenvironmental reconstruction for the site. The associated fauna enables an unambiguous correlation to the Cricetulodon hartenbergeri – Progonomys hispanicus interval local subzone, with an estimated age of 9.98–9.73 Ma (late Vallesian, MN10). Therefore, CPL-M is roughly coeval with the Hispanopithecus laietanus-bearing localities of Can Llobateres 1 and Can Feu 1, and minimally older than those of La Tarumba 1 and Can Llobateres 2. In contrast, CPL-M is younger than the early Vallesian (MN9) localities of Can Poncic 1 (the type locality of Hispanopithecus crusafonti) as well as Polinyà 2 (Gabarró) and Estació Depuradora d’Aigües Residuals–Riu Ripoll 13, where Hispanopithecus sp. is recorded. The associated fauna from CPL indicates a densely forested and humid paleoenvironment with nearby freshwater. This supports the view that Hispanopithecus might have been restricted to dense wetland forests soon before its extinction during the late Vallesian, due to progressive climatic deterioration. Coupled with the existence of other fossiliferous outcrops in the area, this find is most promising for the prospect of discovering additional fossil hominoid remains in the future.

Luminescence dating of a fluvial sequence using different grain size fractions and implications on Holocene flooding activities in Weihe Basin, central China

Abstract Palaeoflood reconstruction is of great importance to extend the flooding records and improve the understanding of their relationships with climatic change and geomorphologic evolution. As a large active rift basin in central China, Weihe Basin subsided and infilled in response to the uplift of the Tibetan Plateau and Asian monsoon variations. Many rivers drain out the erodible Chinese Loess Plateau with tremendous detritus and then build up considerable fluvial sequences. Scarcity of organic material and potential poor bleaching make the fluvial deposits difficult to date with radiocarbon and optically stimulated luminescence (OSL) technique, and as a result hinder the palaeoflood reconstruction. This study attempts to compare OSL ages resulted from different grain size fractions of quartz, and then cross-checks with independent radiocarbon ages, aiming to choose proper method to reconstruct the chronology of a fluvial sequence from the valley bank of Shichuan River, a tributary of Weihe River. The results show that the coarse quartz grains experienced better bleaching than fine quartz grains, and the comparison with AMS 14C ages further confirms the efficient bleaching of the coarse quartz grains before burial. The sufficient bleaching of the coarse fraction could be attributed to sediment source from the upstream mountainous areas and long-distance transportation. Finally, five palaeoflood events were identified at the times of approximately 2.3–2.6 ka, 3.7–3.9 ka, 4.1–4.7 ka, 6.2–6.8 ka, and 8.9–9.2 ka, corresponding to the periods with intensified rainstorm and vegetation degradation associated with climatic deterioration. This study provides a regional evidence to improve our understanding of the response of river system evolution to climate change.