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The aeolian deposits in the coastal region of North China are important for reconstructing paleoclimate. In this paper, chronology, climatic proxies and chemical compositions of four loess sections were studied. Optically stimulated luminescence (OSL) dating results indicate that the coastal loess was accumulated during late Quaternary, with ages ranging from the penultimate glacial period to the latest Holocene. Both granulometric characteristics and geochemical properties indicate that the dust provenance of the coastal loess is partially different from that of the Chinese Loess Plateau, characterized by more proximal contributions. Except distal dust transported by northwesterly winter winds from the inland gobi and sand deserts, the coastal loess also contains proximal, local coarse particles, which were derived from the exposed shelf as well as neighboring hills. Multiple climatic proxies, including color, magnetic susceptibility and particle size parameters, correlate well with the marine SPECMAP δ18O record, indicating that climatic changes in the coastal region of North China during the late Quaternary was mainly controlled by variations of the East Asian monsoon, driven by changes in global ice volumes. • Luminescence dating of coastal loess in eastern North China. • Coastal loess contain both distal and proximal source materials. • Exposed shelf during glacial time serving as an important source for coastal loess. • Costal loess reflects orbital climatic fluctuations driven by East Asian monsoon. [ABSTRACT FROM AUTHOR]

This paper presents new field observations that assist in further defining the extent of Last Permafrost Maximum (LPM) permafrost and frozen ground in north China. In that respect, this region is specific by its arid environment and continental position. Bedrock exposures and sand and gravel pits were examined along a south-north transect from southern Ordos as far as the vicinity of Dongsheng District, Ordos City on the Ordos Plateau (North China). Attention focussed upon the recognition of sand-wedge remains and possible cryoturbations. Two types of wedge structures were recognized: type A wedges extend to depths in excess of 3.0 m and are thought to have formed under conditions of continuous permafrost. Type B wedges are restricted to the upper 1.5 m and are thought to reflect discontinuous permafrost and/or deep seasonal frost. OSL dating of wedge infills indicates that type A wedges formed between 23–19 ka and younger type B wedges formed until the early Holocene. It is now possible to delineate a more exact position of the boundary between continuous permafrost and discontinuous permafrost and/or deep seasonal frost on the Ordos Plateau during the LPM. This boundaries occur between Dongsheng and Jinbian at 37°-39°N. • Precise location of southern limit of continuous permafrost during the Last Permafrost Maximum (c.19-23 ka) in north China. • Narrow zone of discontinuous/sporadic permafrost during the Last Permafrost Maximum (c.19-23 ka) in north China. • Permafrost extent in N China at LPM was specific by its aridity, continentality and proximity to the Siberian High Pressure. [ABSTRACT FROM AUTHOR]

The Luo River is located in the southern part of the Chinese Loess Plateau and the northern part of the Weihe Basin, in Central China. In the basin it flows proximal to the site of the Luyang Wetland core, which is an important archive of climate change over the past 1 Myr in this region. In this paper, the contribution of the Luo River to the sedimentary record is analyzed by reconstructing the evolution of this river during the Middle to Late Pleistocene. It is argued that an alluvial fan of the Luo River has contributed to the sedimentary archive until approximately 200–240 ka. From this moment onwards, the fan became incised and terraces began to form. The formation of a new alluvial fan further downstream led to the disconnection of the Luo River from the Luyang Wetland core site. We propose that this series of events was caused by the displacement of an intra-basinal fault and the resultant faulting-forced folding, which caused increased relative subsidence, and thus increased sedimentation rates at the core site. Therefore, a complete sediment record in the ‘Luyang Wetland’ was preserved, despite the disconnection from the Luo River. The chronology of the fans and terraces was established using existing age control (U-series, ESR, OSL, pIRIR 290 and magnetic susceptibility correlation), and through correlation of the loess-paleosol cover to marine isotope stages. Based on sedimentological characteristics of the fluvial sequence, we suggest that incision of the Luo River occurred in two steps. Small incisions took place at transitions to interglacials and the main incision phases occur at the transition from an interglacial to glacial climate. Due to the incision, basal parts of the oldest Luo River alluvial fan are exposed, and it is in one of these exposures that the famous Dali Man skull was retrieved. This study shows that the Dali Man did not live on a river terrace as previously thought, but on an aggrading alluvial fan, during wet, glacial conditions. [ABSTRACT FROM AUTHOR]

Fossil pollen, as a direct proxy record of past vegetation, and indirect proxy record of past climate, plays an essential role in revealing and reconstructing past vegetation and climate. However, relationships between pollen, vegetation and climate are not linear, hence quantitative reconstructions of past vegetation and climate based on pollen records are not straightforward, and results may be highly contradictory and difficult to interpret. One of the main causes of discrepancies between results has been the lack of comprehensive and systematical studies on modern pollen dispersal and deposition processes, particularly on the quantification of these processes. Based on empirical studies performed in China over the last 30 years, this paper provides the state-of-the-art of the understanding of pollen dispersal and deposition processes in China and the remaining questions to be investigated. We show that major progress has been achieved in the study of modern pollen dispersal and deposition processes, and in the application of models of the pollen-vegetation-climate relationships for quantitative reconstruction of past vegetation and climate. However, several issues are not entirely solved or understood yet, such as how to quantify the reworking and re-deposition of pollen grains in quaternary alluvial sediments, the influence of pollen preservation on pollen assemblages, and human impact on vegetation. Even so, the progress made during the last decades makes it possible to achieve significantly more precise and informative reconstructions of past vegetation, land-use and climate in China than was possible earlier. [ABSTRACT FROM AUTHOR]

This paper reports the discovery of a new mammalian assemblage at Mocun cave in 2000 by the Natural History Museum of Guangxi. The Mocun site is located in a residual karst peak in southwest Guangxi, south China. Abundant mammalian fossil teeth and bones were extracted from relatively thick deposits, well constrained stratigraphically. The results show that 1) the Mocun fauna is composed of typical species of the " Ailuropoda - Stegodon association", including Stegodon, Ailuropoda, Rhinoceros, Pongo, Tapiru s, Megatapirus, and Elephas, common in the Middle to the Late Pleistocene, with a larger portion of modern species; 2) By employing U-series dating (MC-ICP-MS) method on both the soda straw stalactites and mammalian teeth collected from deposits, the age of the Mocun fauna has been constrained between 66 and 101 ka, a transitional period from the interglacial stage MIS5 to the beginning of the last glacial stage (MIS4), representing one of the securely dated Late Pleistocene sites in southern China so far; 3) The composition in large mammals suggests a forested environment which harboured a great biodiversity in large species; 4) The taphonomic analysis indicates that the fossil accumulation is mainly due to activities of porcupines and to water flows; 5) Interestingly, our taxonomic study reveals some changes in the occurrence of Tapirus sinensis and Megatapirus augustus between ∼66 and ∼86 Ka, along with a change in the abundance of artiodactyls versus primates. It remains to demonstrate with more comprehensive records if these changes may be related to the mid-Late Pleistocene climatic transition. • a new mammalian fauna cave site (Mocun cave) with accurate date to 66 and 101 ka in southwest Guangxi. • The composition in large mammals suggests a compatible habitat for a great biodiversity of species. • Some changes between layers with Tapirus sinensis replaced by Megatapirus augustus between ∼66 and ∼86 Ka, along with a change in the abundance of artiodactyls versus primates. [ABSTRACT FROM AUTHOR]

Understanding coastal flooding processes in response to centennial-scale sea-level rise is essential in preparing for the challenge of present-day global warming. Mid-Holocene sea-level rise induced widespread coastal flooding along the East China coast and precipitated the collapse of the Neolithic Liangzhu Culture, the earliest known prehistoric state in East Asia. This paper presents multi-proxy analyses of sedimentology, grain size, total organic carbon (TOC), and alkaline-earth metals extracted by acetic acid (HAc) of a dated sediment core, ZK07, collected from Liangzhu City, with the aim of revealing the detailed progression of coastal flooding phases and the response of prehistoric people at the end of the associated Liangzhu Culture. A three-step succession of coastal flooding processes between ca. 4.6–4.3 cal kyr BP, brought about by relative sea-level rise, is evident in core ZK07. Initially, an increase in the local water level in response to the first phase of sea-level rise is indicated by a gradual increase in TOC at ca. 4630 cal yr BP. Subsequently, at ca. 4520 cal yr BP, a second phase of increased local water-level, consistent with further sea-level rise and salinity intrusion, is suggested by higher Sr concentrations accompanied by a sharp increase in TOC. Thirdly, at ca. 4480–4315 cal yr BP, low TOC content, high - but strongly fluctuating - Sr and Ba concentrations and coarser sediment grain size are all indicative of coastal inundation caused by both storm surges and river flooding associated with typhoon events that correspond with a concurrent phase of accelerated sea-level rise. Considering the evidence of cultural deposits preserved at Liangzhu City, it appears that the Liangzhu people were forced to respond rapidly to the inundation by abandoning the city at ca. 4480 cal yr BP. We suggest that relative sea-level rise and coastal flooding at the terminal stage of the Liangzhu Culture was the regional response to global climate warming and eustatic sea-level rise at that time. Given evidence that a contemporaneous cultural transition took place in the lower Yellow River basin, we further propose that global climate change around 4.5 cal kyr BP had a widespread impact on Neolithic cultural evolution in East China. Furthermore, the rise in local water levels and associated salinity intrusions may be considered as an early warning signal in monitoring future coastal flooding risk. • A three-step succession of coastal flooding was recognized at the end of Liangzhu Culture. • Rise in local water level and salinity intrusion could be early warning of coastal flooding. • Global climate warming and eustatic sea-level rise at ca. 4.5 ka was the major mechanism. • Contrasting Neolithic cultural evolution occurred in the lower reaches of two large rivers in East China. [ABSTRACT FROM AUTHOR]

Peatlands are one of the most significant carbon reservoirs in the terrestrial ecosystem. Understanding past peatland carbon accumulation processes and their responses to varying external and internal forcing factors would help reveal the general development patterns of peatland ecosystems and provide useful insights into projecting the fate of carbon reservoirs into the future. In this paper, the basal ages of 17 peat cores were used to explore the lateral expansion processes of the Laolike peatland, northeast China. Two cores were selected to calculate carbon accumulation rates (CAR) and reconstruct moisture/precipitation records based on δ13C and grain size analyses. The basal ages show that the peatland was initiated at 12.1 cal kyr BP, then laterally expanded with its fastest rate occurring during the early Holocene, and reached its largest area around 6 cal kyr BP. The time-weighted mean CAR in the Laolike peatland ranged from 31.1 to 52.9 g C/m2/yr (with an average of 42 g C/m2/yr) during the Holocene. The peatland experienced a high CAR of 52.5 g C/m2/yr from 11.7 to 5 cal kyr BP, followed by a low CAR of 35.1 g C/m2/yr after 5 cal kyr BP. Both lateral expansion and vertical accretion are consistent with the summer insolation, climate seasonality, and the strength of the East Asia summer monsoon (EASM) over multi-millennium timescales, where the CAR correlated well with δ13C and grain size, implying moisture/precipitation might be the primary factors controlling carbon accumulation over millennium timescales. Local conditions, such as topography and hydrology, also played an important role in the process of peatland initiation and lateral expansion, as well as the discrepant CAR within the peatland. This study reveals the roles of climate and local conditions in peatland initiation, expansion, and CAR during the Holocene. In addition, we provide a window for a better understanding of the driving factors of peatland development in the temperate zones of the Northern Hemisphere. • Climate conditions are the primary control on the lateral expansion and vertical accretion of Laolike peatland over multi-millennium timescales. • Moisture/precipitation affects carbon accumulation of Laolike peatland over millennium timescales. • Local conditions play an important role in the lateral expansion and the internal differences of carbon accumulation rate. [ABSTRACT FROM AUTHOR]

Speleothem records from NE Asia are essential to understand the spatial patterns of the Asian Summer Monsoon (ASM) variability. In this paper, we present a new high-resolution and chronologically well-resolved speleothem record from Liu-li (LL) cave, NE China, through δ18O, δ13C and Sr/Ca ratio characterizing a dynamic ASM history over the past 6680 years. The LL δ18O record shows a long-term trend to higher values, following the North Hemisphere summer insolation (NHSI), with the exception of the last 2 kyr characterized by a negative δ18O excursion. The '2-kyr shift' is evident in NE Asia over the past 2 kyr, originally inferred from the speleothem δ18O negative excursion in South China, as well as in many other proxy records from East China, but it merely manifests a flat trend in most of the western East Asian Summer Monsoon (EASM) and Indian Summer Monsoon (ISM) regions, rather than a negative excursion. On multi-centennial to millennial timescales, the intensification of the Tsushima Warm Current (TWC) can amplify rainfall on both sides of the Japan Sea. A close comparison between the monsoon reconstruction and the cultural changes in NE Asia suggests contemporary climatic and cultural regime-shifts, implying an important role of the ASM weakening in the collapse of Neolithic and Early Bronze cultures in this region. • The records we present and the comparison with many regional paleoclimate records offers new evidences of the distribution of the '2-kyr shift'. • On multi-centennial to millennial timescales, the covariation of different records in NE Asia suggests that the intensification of the Tsushima Warm Current can amplify rainfall on both sides of the Japan Sea. • The contemporary climatic and cultural regime-shifts suggest that the monsoon weakening might play an important role in the collapse of the Neolithic and Early Bronze cultures from this region. [ABSTRACT FROM AUTHOR]