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Habitat fragmentation can facilitate local adaptation of species to heterogeneous environments and affect population demographic history. To understand the factors influencing evolutionary dynamics, such as climatic fluctuations and complex geomorphological features, we used 18 chloroplast microsatellites, 15 nuclear microsatellites, three chloroplast fragments, and two nuclear regions to explore the genetic structure and phylogeographical history of Pseudotaxus chienii. Furthermore, its current and past distributions were constructed based on ecological niche modelling. Moderate to high levels of genetic diversity were found at the species level. Precipitation was a decisive factor influencing the genetic structure of P. chienii. In addition, local adaptation to heterogeneous environments also contributed to maintain the fragmented distribution. Finally, incomplete lineage sorting led to the cyto-nuclear discordance. Overall, we show that pre-Quaternary and Quaternary climatic fluctuations and restricted gene flow exerted significant effects on the formation and maintenance of the fragmented distribution of P. chienii. The study provides new insights into the evolutionary history of plants in subtropical China. [ABSTRACT FROM AUTHOR]

Pleistocene climatic oscillations exerted significant influences on the genetic structure and demography of rhesus macaque (Macaca mulatta) in eastern China. However, the evolutionary history of rhesus macaques in subtropical and temperate China remained unclear and/or controversial. Herein, we analyzed the autosomes, mitochondrial genomes, and Y‐chromosomes from 84 individuals of Chinese rhesus macaque. The results revealed that (1) all individuals were clustered into pan‐west and pan‐east genetic groups, which exhibited Shaanxi Province as the northernmost region of western dispersal route of rhesus macaques in China; (2) in subtropical and temperate China, rhesus macaques were divided into four lineages (TH, DB, HS, and QL), and their divergence times corresponded to the Penultimate Glaciation (300–130 kya) and Last Glaciation (70–10 kya), respectively; (3) the individuals from Mt. Taihangshan (TH) are closely related to individuals from Mt. Dabashan (DB) in the autosomal tree, rather than individuals from Mt. Huangshan (HS) as indicated by the mitogenome tree, which supports the hypothesis that the ancestral rhesus macaques radiated into Mt. Taihangshan from Mt. Huangshan via Mt. Dabashan; and (4) the demographic scenario of the four lineages showed the ancestral rhesus macaques bottleneck and expansion corresponding to the suitable habitat reduction and expansion, which confirmed they had experienced northward recolonization and southward retreat events from Mt. Huangshan area via Northern China Plain to Northernmost China along with Pleistocene glacial cycles. This study provides a new insight into understanding how Pleistocene glaciation has influenced faunal diversity in subtropical and temperate China, especially for those exhibiting differential patterns of sex dispersal. [ABSTRACT FROM AUTHOR]

Investigation of rarely studied gravel layers found in the loess in Shandong Province, eastern China, reveals the fabric characteristics of two gravel layers (G1, G2) and the sedimentary characteristics of loess at the typical and well‐preserved Heiyu section (HY), where, to determine the paleoclimatic changes during Marine Isotope Stage 3a. Optically stimulated luminescence dates of the HY formation range from 0.26 ± 0.02 ka to 39.00 ± 2.00 ka. In addition, the ages of G1 and G2 were estimated using the Bayesian model to be 39.60–40.50 and 29.00–29.50 ka. G1 and G2 are mainly composed of fine and medium gravel, both of which were subangular to subrounded limestone, with gravel directions to NE and E. The average flow velocity, average depth, and flood peak flow of G1 are 1.10 m/s, 0.49 m, and 37.04 m3/s, respectively, calculated using the flow energy method, whereas those of G2 are 0.98 m/s, 0.38 m, and 18.38 m3/s, respectively. Analysis of climate proxy indices show that the sedimentary environment of the gravel and loess in HY might be a regional response to global change. [ABSTRACT FROM AUTHOR]

The Cryogenian Sturtian and Marinoan glaciations stand as the most extreme climate events in Earth history. Intriguingly, large-scale Mn carbonates characterize the nonglacial interlude of this period in South China. The formation mechanism of Mn carbonates and the potential correlation underlying this temporal association remain elusive. Here, we present an integrated petrographic and geochemical study of drill core materials intercepting the Mn-bearing Datangpo Formation. Rare earth element patterns of these Mn carbonates exhibit positive Ce anomalies and a lack of Y anomalies, which differ from those of modern seawater but resemble marine Mn-Fe oxides. These features, combined with negative carbonate carbon isotope compositions (δ13C carb as light as −9.9 ‰ VPDB), indicate the presence of oxide precursors and the incorporation of light carbon during Mn-carbonate precipitation. Phosphate oxygen isotope ratios (δ18O p) of HCl-extractable apatite reveal a ∼4 ‰ difference in the average δ18O p between Mn-rich and Mn-poor rocks. We propose that the more positive δ18O p of Mn-rich samples may result from the dominance of phosphate released by reductive dissolution of metal oxides or a heavier oxygen isotope signal of surrounding waters with which isotopic equilibrium has been reached. We further illustrate how marine invasions into coastal anoxic basins could have triggered the formation of Mn oxides and highlight the role of glaciation–deglaciation in the development of giant Mn deposits. [ABSTRACT FROM AUTHOR]

Eriophyoid mites are among the most species‐rich superfamilies (Eriophyoidea) in the Acari, consisting of over 5000 named species. Although they exhibit a geographically uneven worldwide distribution, their regional spatiotemporal evolutionary patterns remain largely unknown. Here, we compiled a data set including 3058 occurrence records assigned into 1203 species in China. We found that eriophyoid mite species richness is higher in the southeast and lower in the northwest of China, coinciding with the 500‐mm annual precipitation isoline. Using fragments of two mitochondrial genes (COI, 12S rRNA) and two nuclear genes (18S rRNA, 28S rRNA) of 304 eriophyoid mite species, we constructed a regional dated phylogenetic tree in China. Our spatiotemporal analysis revealed that mountains in eastern and southern China had high eriophyoid mite species richness and phylogenetic clustering, possessing both ancient and young mite lineages. Species distribution modelling (SDM) results showed that the predicted suitable area of eriophyoid mites slightly expanded from the last inter‐glacial period to the last glacial maximum period. In comparison with the current SDM, a significantly larger distribution range was observed in future scenarios. These findings suggest that mountains in eastern and southern China acted as not only cradles—recent rapid speciation, but also museums—centre of gradual accumulation and preservation and provide insights into monitoring and conserving eriophyoid mites. [ABSTRACT FROM AUTHOR]

China has the most numerous Danxia and Karst landscapes, which serve as special terrestrial islands harboring ample endemic species, though how did these endemic species spread among those isolated sites is still an unresolved issue. To address this question, we explored the phylogeographical structure and demographic history of Firmiana danxiaensis, a tree species endemic to Danxia and Karst landscapes. We collected 295 samples (28 populations) of F. danxiaensis. Plastid genomes were assembled for 25 representative samples. Sanger sequencing of four plastid regions and restriction‐site‐associated DNA sequencing were performed on the 28 populations. The phylogenetic tree constructed from plastid genomes and restriction site‐associated DNA sequencing (RAD‐seq) data supported that F. danxiaensis originated from Mount Danxia and Nanxiong Basin, spread to Karst landscapes near Yingde City, and then back to Danxia Mountain and the Nanxiong Basin. In the Nanxiong Basin, the latter arrivals captured the plastid of the former. Population analyses revealed strong population structure among and within Danxia and Karst landscapes, possibly due to low seed and pollen dispersal abilities of the species. The demographic and ecological niche modeling approaches suggested that F. danxiaensis have widely occurred in the southeast of China during the last glacial period, and later retreated to the cliffs of Danxia and Karst landscapes due to temperature rising and competition failure. The declining of the effective population size of the species throughout the postglacial period suggested that global warming, agriculture, and industrial civilizations could have affected the survival of this species, and more measures should be taken to conserve these species. [ABSTRACT FROM AUTHOR]

Glacial diamictite may provide important information on paleoenvironment and average composition of the upper continental crust (UCC). In this study, we report sedimentary facies, petrological and geochemical characteristics of Neoproterozoic diamictite from a profile of the Luoquan Formation on the southern margin of the North China Block (NCB). Upwards the sampling profile, lithostratigraphic strata vary from massive diamictite with poorly sorted carbonate gravels to laminated diamictite with small gravels of terrestrial detrital materials. Along the profile, CaO-MgO-LOI-Sr values decrease with the increase of SiO2-Al2O3-K2O contents. All these petrological and geochemical variations indicate a change from lodgement till deposition in the proximal of ice sheet to ice-rafting deposition in glacial-marine environment with less dolomite to supply their source. Together with previous studies on diamictite from other outcrops on the NCB, the deposition of Luoquan diamictite reflects that the glaciation on the NCB vanished and the ice-rafting effect weakened with glacial transgression process. In addition, significant co-variations of various elements with La and Al2O3 confirm the significant conservation of most analyzed elements during the sedimentary processes to produce diamictite. [ABSTRACT FROM AUTHOR]

Siniperca undulata and S. obscura (Centrarchiformes: Sinipercidae) are small Chinese perches, living in creeks and streams in southern China. While they have sympatric distribution and occupy similar macrohabitat, their body sizes and ecological niches have many differences. Determining the genome sequences of S. undulata and S. obscura would provide us an essential data set for better understanding their genetic makeup and differences that may play important roles in their adaptation to different niches. We determined the genome sequences of both S. undulata and S. obscura using 10× genomics technology and the next-generation sequencing. The assembled genomes of S. undulata and S. obscura were 744 and 733 Mb, respectively. Gene family analysis revealed that there were no overlap between S. undulata and S. obscura in terms of rapid expanding and rapid contracting genes families, which were related to growth, immunity, and mobility. Positive selection analyses also cooperated that the function of selected genes involve growth, athletic ability, and immunity, which may explain the preference of different niches by S. undulata and S. obscura. Pairwise sequentially Markovian coalescent analyses for the two species suggested that populations of both S. undulata and S. obscura showed a rising trend between 90 and 70 Ka probably due to the mild environment during the last interglacial period. A stage of population shrinking occurred from 70 to 20 Ka, which was in with the Tali glacial period in eastern China (57-16 Ka). [ABSTRACT FROM AUTHOR]

Siraitia grosvenorii, an economically important plant species with high medicinal value, is endemic to subtropical China. To determine the population structure and origin of cultivated S. grosvenorii, we examined the variation in three chloroplast DNA regions (trnR‐atpA, trnH‐psbA, trnL‐trnF) and two orthologous nuclear genes (CHS and EDL2) of S. grosvenorii in 130 wild individuals (selected from 13 wild populations across its natural distribution range) and 21 cultivated individuals using a phylogeographic approach. The results showed three distinct chloroplast lineages, which were restricted to different mountain ranges, and strong plastid phylogeographic structure. Our findings suggest that S. grosvenorii likely experienced ancient range expansion and survived in multiple refuges in subtropical China during glacial periods, resulting in population fragmentation in different mountainous areas. Our results also demonstrated that wild populations in Guilin (Guangxi, China) share the same gene pool as cultivated S. grosvenorii, suggesting that current cultivars were collected directly from local wild resources, consistent with the principles of "nearby domestication." The results of this study provide insights into improving the efficiency of S. grosvenorii breeding using a genetic approach and outline measures for the conservation of its genetic resources. [ABSTRACT FROM AUTHOR]

The Sturtian (720–670 Ma) glacial–interglacial transition period was an important interval for sedimentary manganese metallogenesis, including the Mn oxide deposit in the Otjosondu region in Namibia and Mn carbonate deposits in the Datangpo Formation in the south-eastern Yangtze Platform, South China. During this period, Earth experienced the breakup of Rodinia, the Sturtian glaciation, and the Neoproterozoic oxygenation event. In this study, we investigate scenarios that might have provided geologically and geochemically favorable conditions for Mn metallogenesis. In these scenarios, the global recovery of microorganisms enhanced marine primary productivity and O2 levels of the hydrosphere and atmosphere during the Sturtian glacial–interglacial transition. However, the water column was not completely oxidized, maintaining redox stratification. Transgression–regression cycles or O2-rich downwelling drove the exchange of oxygenated topwater and anoxic deep water in rift-related basins that developed due to Rodinia's breakup. The coupling of these processes precipitated existing dissolved Mn(II) at the margins of basins (Otjosondu region) or at their centers (Yangtze Platform). In the latter case, precursor Mn oxides were further converted into Mn carbonates via the reduction of Mn oxides coupled with organic matter oxidation during early diagenesis. A brief review of Mn metallogenesis in the geological record reveals that Mn metallogenic processes typically occur under geo-environmental conditions that, in concert, produce favorable conditions for Mn sourcing, concentration, and sedimentation. [ABSTRACT FROM AUTHOR]

Effective moisture (EM) distribution in the Indian summer monsoon (ISM) region is strongly related to regional topography. An understanding of climate change and the interactions between climate variables can help predict future climate variations. Here, we reconstruct a stack EM record for Southwest China over the past 90 kyr using environmental magnetism in lake sediment. The EM in Southwest China at the orbital scale was closely linked to precession‐induced change in North Hemisphere solar insolation, as well as the ISM variability. However, at the glacial‐interglacial scale, it was decoupled with ISM intensity, being wetter during glacial periods (weakened ISM) and drier during interglacial periods (enhanced ISM). Combined with modern meteorological observations, we suggest that the topographical barrier effect and temperature induced dryness are responsible for the decoupling between ISM intensity and EM. The terrestrial topography and temperature strongly influence EM distribution by altering the dynamics of onshore airflow and evapotranspiration. Plain Language Summary: Effective moisture (EM) directly affects hydrological cycle and wider‐scale socio‐economic development. Reconstruction of prehistoric EM levels is essential for deeper understanding of the global climate system, developing climate models and improving prediction of future climate variations. Here, we reconstruct a high‐resolution EM record over the past ∼90,000 years from lake sediments in Tengchong, Yunnan province, Southwest China. We found that the variation of precession (shifts in the rotational axis of the Earth) and solar insolation are the key contributors to the EM variability at the orbital scale. Unusually, a wetter climate during the glacial period and relatively drier interglacial periods were observed in our records, which is opposite to those found in previous studies (arid glacial and humid interglacial) in monsoon regions, indicating a decoupling pattern between monsoon intensity and EM in study region. Based on a comprehensive analysis of the modern meteorological observations, we conclude that the topography and temperature exert a considerable role in modulating EM distribution and response to the decoupling pattern. Key Points: The long‐term effective moisture (EM) record in Southwest China since ∼90 kyr was reconstructedThe EM variability at the orbital scale in terrestrial Indian summer monsoon region is primarily dominated by precessionThe topographic barrier and temperature induced aridification contribute to the decoupling of monsoon intensity and EM [ABSTRACT FROM AUTHOR]

The study of fire history and driving mechanisms at long time scales can provide a theoretical background for future fire management in forested regions. The alpine lake sediments from Daye Lake in the Qinling Mountains, east‐central China, were used to explore the influence of climate, vegetation and human activity on fires since the LGM, based on charcoals and black carbon. During the last glacial period, fire activity was mostly controlled by regional aridity under a weak East Asian summer monsoon, while human‐induced fires were commonly dominated in the late Holocene. Fire activity was found to be linked to biomass through temperature variability. The biofuel dominated by conifers induced high intensity fires in the last glacial, and herbs contributed more to the high fire frequency over the mid‐late Holocene. With predicted future rising temperatures, increased vegetation cover and extreme climate events may increase the fire risk in the region. Plain Language Summary: Fire activity has an important influence on climate changes and carbon cycling. Understanding past fire history and its driving mechanisms are essential to mitigate the impact of fires. Here, we present fire records from alpine lake sediments in the Qinling Mountains since the LGM. Results indicate that climatological drought under a prevailing weak East Asian summer monsoon increased fire activity during 21.6–11.7 cal ka BP, while human‐induced fires became more common in the late Holocene due to land use, for example, the forest clearing for agriculture and the warfare. And high temperature increases fuel loads, resulting in more fires. Moreover, vegetation types with varying biofuel supply also influence fire activity. We suggest that fire risk may increase in the region with future rising temperature. Our results have implications for understanding fire history and management in other transitional vegetation zones globally. Key Points: The prevailing weak East Asian summer monsoon mostly controlled fire activity during the last glacial, whilst human activity became common through the HoloceneThe conifers induced high intensity fires in the last glacial and herbs contributed more to high fire frequency over the mid‐late HoloceneForest resources in east‐central China will face the increased fire risks in the context of global warming and increasing vegetation cover [ABSTRACT FROM AUTHOR]

Background: The evergreen broadleaved forest (EBLF) is an iconic vegetation type of East Asia, and it contributes fundamentally to biodiversity-based ecosystem functioning and services. However, the native habitat of EBLFs keeps on decreasing due to anthropogenic activities. Ormosia henryi is a valuable rare woody species in EBLFs that is particularly sensitive to habitat loss. In this study, ten natural populations of O. henryi in southern China were sampled, and then genotyping by sequencing (GBS) was applied to elucidate the standing genetic variation and population structure of this endangered species. Results: In ten O. henryi populations, 64,158 high-quality SNPs were generated by GBS. Based on these markers, a relatively low level of genetic diversity was found with the expected heterozygosity (He) ranging from 0.2371 to 0.2901. Pairwise FST between populations varied from 0.0213 to 0.1652, indicating a moderate level of genetic differentiation. However, contemporary gene flow between populations were rare. Assignment test and principal component analysis (PCA) both supported that O. henryi populations in southern China could be divided into four genetic groups, and prominent genetic admixture was found in those populations located in southern Jiangxi Province. Mantel tests and multiple matrix regression with randomization (MMRR) analyses suggested that isolation by distance (IBD) could be the possible reason for describing the current population genetic structure. In addition, the effective population size (Ne) of O. henryi was extremely small, and showed a continuous declining trend since the Last Glacial Period. Conclusions: Our results indicate that the endangered status of O. henryi is seriously underestimated. Artificial conservation measures should be applied as soon as possible to prevent O. henryi from the fate of extinction. Further studies are needed to elucidate the mechanism that leading to the continuous loss of genetic diversity in O. henryi and help to develop a better conservation strategy. [ABSTRACT FROM AUTHOR]

Clues of climate change on the Alashan Plateau since the last glacial period (40 ka) are important for revealing the mechanism of desertification of middle-latitude deserts in the Northern Hemisphere (NH). Studies are still rare for the understanding of the specific relationship of climate changes between the Alashan Plateau and the global. Based on a systematic and comparative analysis of the existing research in China and the international academic community, this paper reviews the environmental evolution history of the Alashan Plateau since the last glacial period from the records of paleo-environment and geomorphological characteristics in different deserts of the plateau (e.g., Badanjilin, Tenggeli, and Wulanbuhe). From about 40 ka to the end of the last glacial maximum, the climate on the plateau was wetter than it is today, and to the end of the Pleistocene, the climate was generally dry and the aeolian activities were enhanced. However, the climate was arid during the whole last glacial period in the Wulanbuhe Desert, evidently different from the overall pattern of the plateau. The Tenggeli Desert was characterized by an arid climate in the early Holocene. The most controversial events for the Alashan Plateau are the drought events in the middle Holocene in the Badanjilin Desert. The role and impact of the westerlies and the East Asian Summer Monsoon (EASM) systems on the climate change of the desert and even the whole plateau is a vexed question that brings different views in different periods. There is still a lack of definite evidence representing the events of global environmental change that occurred on the plateau during the discussed period. The distinctive morphology of dune mountains and the distribution of sand dunes are mutually indicative of the direction and energy of wind systems on the plateau. It is suggested that appropriate wind energy is the significant key to the desertification in these middle-latitude deserts on the plateau. From a global-scale review of climate change, the desertification of the modern-scale sandy desert landscapes on the Alashan Plateau is generally related to the global glacial period and the cold and dry climate during the past 40 ka. [ABSTRACT FROM AUTHOR]

The rainfall changes in East Asian summer monsoon (EASM) regions on the orbital timescale remain controversial due to the lack of reliable rainfall records. Here, we present new multiproxy records (δ18O, δ13C, Sr/Ca and Mg/Ca) of a 230Th-dated stalagmite from Hulu Cave in central eastern China. Multiproxy records reconstruct a regional hydroclimate history from 340 to 261 kyr BP (thousand years before present), approximately covering the antepenultimate glacial period. The δ18O record is dominated by the precessional cycles, suggesting that EASM responds to changes in Northern Hemisphere summer insolation (NHSI) on the orbital timescale. Significant correlations amongst the δ13C, Sr/Ca and Mg/Ca suggest that a common factor, i.e., the local hydrological cycle, controlled their variability, and their leading principal component can be used as a proxy linked to regional rainfall. This composite record bears a good similarity to those from the Chinese Loess Plateau, showing a gradually decreasing rainfall during the antepenultimate glacial period, consistent with changes in global ice volume. Superimposed on the long-term trend, three relative wetter intervals were responding to the higher NHSI periods, suggesting that EASM rainfall variability was induced by integrated effects of global ice volume and NHSI. The increased ice sheets and lower NHSI resulted in an increased meridional temperature gradient and southward shift of the westerlies, which shortened the duration of Meiyu and midsummer rainfall. The differences between the rainfall record and the stalagmite δ18O record indicate that the latter represents the overall EASM intensity linked to monsoon circulation, but does not directly reflect the rainfall changes at the cave sites. [ABSTRACT FROM AUTHOR]

Mio‐Pliocene sedimentary archives of the East Asian summer monsoon (EASM) in NE Tibet record a monotonic response to orbital forcing, dominated by eccentricity. By contrast, Pleistocene archives display a more stochastic response that varies regionally and temporally. When and why this response changed is poorly understood. Here, we present a new high‐resolution Rb/Sr ratio data set of EASM intensity from the Sanmenxia Basin, North China, that spans the Plio‐Pleistocene transition. Our results indicate decreased monsoonal rainfall in the late Pliocene, dated at 2.75–2.6 Ma, associated with an intensified response to obliquity and enhanced climate stochasticity. This transition is attributed to the increase of Northern Hemisphere ice volume. Quaternary monsoons display a sensitivity unique to the modern icehouse with large bipolar ice sheets, while pre‐Quaternary monsoons were solely impacted by Antarctic ice sheet dynamics on orbital time‐scales. Plain Language Summary: The late Pliocene‐early Pleistocene transition (LP/EP) is a period of global cooling and the intensification of Northern Hemisphere glaciation. Yet, the evolution of the East Asian summer monsoon (EASM) during this time remains a topic of ongoing discussion and debate. Here we present high‐resolution paleoclimate data from a record of lake sediments across the Pliocene‐Pleistocene transition period. We show that there was a reorganization of the East Asian monsoon system 2.75–2.6 million years ago, associated with an increase in climate forcing caused by cyclic changes in Earth's tilt and in climate stochasticity. This transition is attributed to the appearance of new high‐latitude forcing mechanisms on monsoon intensity caused by the growth of ice sheets in the Northern Hemisphere. Key Points: Cyclic patterns in East Asian summer monsoonal intensity during the Pliocene were mainly driven by Antarctic ice sheet variationsA major reorganization of the East Asian climate system occurred at 2.75–2.6 Ma in response to Northern Hemisphere glaciationQuaternary East Asian summer monsoon on orbital scales displays a sensitivity that is unique to the modern icehouse with bipolar ice sheets [ABSTRACT FROM AUTHOR]

Studying the evolution of genomic divergence between lineages is a topical issue in evolutionary biology. However, the evolutionary forces that shape the heterogeneous divergence of the genomic landscape are still poorly understood. Here, two wind‐pollinated sister‐species (Ostrya japonica and O. chinensis) are used to explore what these potential forces might be. A total of 40 individuals from 16 populations across their main distribution areas in China were sampled for genome‐wide resequencing. Population demography analyses revealed that these two sister‐species diverged at 3.06–4.43 Mya. Both population contraction and increased gene flow were detected during glacial periods, suggesting secondary contact at those times. All three parameters (DXY, π, and ρ) decreased in those regions showing high levels of differentiation (FST). These findings indicate that linked selection and recombination played a key role in the genomic heterogeneous differentiation between the two Ostrya species. Genotype–environment association analyses showed that precipitation was the most important ecological factor for speciation. Such environmentally related genes and positive selection genes may have contributed to local adaptation and the maintenance of species boundaries. [ABSTRACT FROM AUTHOR]

It is not well understood how, in the immediate aftermath of the Sturtian Snowball Earth, marine sulfur cycling resulted in a global distribution of sedimentary pyrite with δ34S values higher than coeval seawater. Here, we analyze the quadruple sulfur isotope systematics of organic-bound sulfur (OS) from the lowermost post-Sturtian Datangpo Formation, South China, and identify two generations of OS formation, each sampling an isotopically distinct sulfate reservoir (δ34S ≈ 26‰ and 52–93‰) that differentially impacted its respective, co-occurring pyrite. Combining several lines of geochemical evidence, we argue that the first OS generation was the product of a sulfate-impoverished meltwater-influenced setting, with OS preservation being the result of resistance to acid hydrolysis. However, the second OS generation was sourced from H 2 S produced in sediments during early diagenesis via microbial reduction of a 34S-enriched sulfate pool derived from overlying euxinic or ferruginous seawater. This is the first ancient marine data set where all observed pyrite is more enriched in 34S than its associated OS. Our proposed origin may be applied to global superheavy pyrite (SHP) immediately after the Sturtian and is comparable to processes linked to freshwater-to-marine transitions during rising sea level in the wake of recent glaciation. [ABSTRACT FROM AUTHOR]

The Quaternary was the main evaporite deposition period in the Qaidam Basin (QB), but the correlation between the evaporite deposition period and the glacial period is still unclear. In this study, the research objects are primarily evaporite‐bearing strata in a 461.58 m‐long drill core in the QB. X‐ray powder diffraction (XRD) and scanning electron microscopy (SEM) were applied to study the evaporite minerals, U‐Th dating being applied to construct the 230Th geochronological framework. Evaporite deposition from Marine Isotope Stage (MIS) 15 to MIS 4 in the borehole was reconstructed via mineralogical and geochronological data. The evaporite minerals are mainly halite (NaCl), mirabilite (Na2SO4·10H2O), thenardite (Na2SO4) and gypsum (CaSO4·2H2O). A total of 9 effective 230Th data points, ranging from 492.5 ± 43.0 ka to 62.0 ± 11.9 ka, were obtained. The depositional age of the earliest halite layer in the borehole is 592.5–563.0 ka. There were mirabilite deposits in the QB during the cold glacial environment of MIS 6. During MIS 4, the study area desiccated, with mirabilite and halite being deposited. This study suggests that mirabilite is an indicator mineral for the glacial environment in the QB, while halite deposition does not correspond well to glaciation. [ABSTRACT FROM AUTHOR]

A multidecadal-resolved stalagmite d18O record from two nearby caves, Lianhua and Dragon, in Shanxi Province, northern China, characterizes the detailed East Asian summer monsoon (EASM) intensity changes at 114.6-108.3 ka during Marine Oxygen Isotope Stage 5d. Our record shows an intensification of the EASM at 114.6-109.5 ka, followed by a rapid weakening at 109.5-108.4 ka. The millennial-scale strong monsoonal event appears to be correlated with the warm Greenland interstadial 25 (GI 25), whereas the weak monsoonal event is related to the cold Greenland stadial 25 within dating errors. The GI 25 monsoonal event registered in our record is also documented in various published time series from different regions of China. The lines of evidence indicate that this event occurred over the entirety of monsoonal China and was also broadly antiphase, similar to the corresponding event on a millennial time scale in the South American monsoon territory. In our record, one 700 yr weak monsoon event at 110.7+0.6 -0.5 to 110.0+0.8 -0.4 ka divides the GI 25 into three substages. These multicentennial to millennial-scale monsoon events correspond to two warm periods and an intervening cold interval for the intra-interstadial climate oscillations within GI 25, thus supporting a persistent coupling of the high- and low-latitude climate systems over the last glacial period. [ABSTRACT FROM AUTHOR]

Simple Summary: In the current study, we estimate the genetic diversity of the salangid Neosalanxtaihuensis sampled from 11 populations in the six typical river basins of China. Using the COI gene sequencing technology, the N. taihuensis population's genetic difference within and between river basins was investigated. Significant levels of genetic subdivision were detected among populations within basins rather than between basins. Population history dynamics showed that N. taihuensis populations experienced a population expansion during the glacial period in the late Pleistocene. These results suggest that different populations should be considered as different management units to achieve effective conservation and management purposes. The salangid Neosalanx taihuensis (Salangidae) is a commercially important economical fish endemic to China and restricted to large freshwater systems with a wide-ranging distribution. This fish species has continuous distribution ranges and a long-introduced aquaculture history in Chinese basins. However, the research on its population genetic differentiation within and between basins is very limited. In this regard, 197 individuals were sampled from 11 populations in the Nenjiang River Basin (A1–A4), Songhua River Basin (B1), Yellow River Basin (C1–C2), Yangtze River Basin (D1), Lanchang River Basin (E1–E2) and Huaihe River Basin (F1). Based on the COI sequence, the N.taihuensis population's genetic difference within and between river basins was investigated. The haplotypes and their frequency distributions were strongly skewed, with most haplotypes (n = 13) represented only in single samples each and thus restricted to a single population. The most common haplotype (H4, 67/197) was found in all individuals. The analysis of molecular variance (AMOVA) revealed a random pattern in the distribution of genetic diversity, which is inconsistent with contemporary hydrological structure. The mismatch between the distribution and neutrality tests supported the evidence of a population expansion, which occurred during the late Pleistocene (0.041–0.051 million years ago). Significant levels of genetic subdivision were detected among populations within basins rather than between the six basins. Population history dynamics showed that N. taihuensis experienced an expansion during the glacial period in the late Pleistocene. Therefore, different populations should be considered as different management units to achieve effective conservation and management purposes. These results have great significance for the evaluation and exploitation of the germplasm resources of N. taihuensis. [ABSTRACT FROM AUTHOR]

• The Fulu Formation in South China records a rapid deglaciation of the Sturtian glaciation. • The post-glacial cherts sharply overly the Sturtian glacial diamictite. • These cherts suggest elevated continental weathering after the end of the Sturtian glaciation. The cap carbonates are markers indicating the end of the Sturtian (717–660 Ma) and Marinoan (∼650–635 Ma) global glaciations. These carbonates precipitated from oversaturated seawater, which was caused by intense continental chemical weathering under extremely high atmospheric CO 2 levels. Unlike the widespread Marinoan cap carbonate, the Sturtian cap carbonate is restricted, questioning the uniformity of the two post-glacial weathering processes. This study presents a sedimentological analysis of the basinal Sturtian deglacial succession in the Cryogenian Fulu 4th member, South China. The analysis identifies four facies associations: the proglacial diamictite facies association, the glaciomarine shale facies association, the distributary gravelly sandstone facies association, and the turbidite facies association. Notably, the glacial diamictite is directly overlain by chert, revealing an abrupt end of the Sturtian glaciation. The chert is composed of equidimensional granular microquartzs, and is characterized by high total Fe 2 O 3 contents (0.29–0.97 %, mean = 0.50 %), low Ge/Si ratios (0.50–0.68 μmol/mol, mean = 0.61 μmol/mol), left-leaning PAAS-normalized REE patterns, coupled Eu/Eu* and Y/Ho ratios. These results suggest that the Si source is from post-glacial weathering, with a minor hydrothermal influence. This study supports an enhanced weathering response in the termination of the Sturtian glaciation, providing insights from a Si perspective into the deglacial geochemical processes. The restricted occurrence of chert implies that silicate weathering and its signature may have been spatially variable, which is an important consideration for future research. [ABSTRACT FROM AUTHOR]

In the piedmont of uplifting mountains, alluvial fan rivers undergo significant aggradation-degradation processes, which are usually attributed to climate change. An ongoing debate is whether this process requests the participation of glaciation. To address this debate, we need the knowledge of the quantitative relationship between the ratio of water to sediment flux (q w / q s) with the aggradation/degradation process. This study examined the aggradation and degradation processes in three alluvial rivers at the piedmont of the Qilian Shan (Shan referes to Mountain) and simulated the river processes by a one-dimensional numerical model based on the transport-limited principle. Along the studied piedmont rivers, field measurements show a magnitude of 120–200 m degradation and aggradation in the Late Pleistocene. Through simulation analysis, we explored how factors like the ratio of water to sediment flux (q w / q s), channel width, and sediment grain size influence river processes and longitudinal profiles, and found distinct morphologies in different processes, where aggradation is characterized by concave-up profiles, while degradation is characterized by convex-down profiles. Additionally, the water flux is inversely proportional to the time required for the river to reach a new equilibrium profile. The simulated degradation amplitude aligns closely with the measured data in the Qilian Shan, indicating that precipitation during the Last Glacial Maximum in the region amounted to approximately ∼32% of the Holocene precipitation. This supports the notion that changes in water flux or precipitation alone can induce significant piedmont deepening without the necessity of glaciation. • Built a model to quantify the link between water-sediment fluxes and river processes. • Simulated Qilian Shan piedmont river incision: ∼32% LGM precipitation vs. Holocene. • Precipitation alone can create deep canyons without requiring glaciation. [ABSTRACT FROM AUTHOR]

• First report of Hg records at the deep-sea facies of the Cryogenian Datangpo Fm. • The near zero Δ199Hg value in the Mn-ore layer suggest a volcanic origin. • The thick Hg-rich layer with positive Δ199Hg in the suggests a DOC reservoir existed. • The Hg-rich layer was formed by Hg-DOC release in anoxic conditions. An interglacial period existed between the Sturtian (ca. 720 ∼ 660 Ma) and the Marinoan glacial period (ca. 650 ∼ 635 Ma) in the Cryogenian. It is manifested as the Mn-bearing black rock series of the Datangpo Formation in the Nanhua rift basin, South China. In the Datangpo Formation in the Xiangtan area, a continuous mercury-rich stratum nearly 60 m thick was found, while in a previous study of the Wuhe section of the shallow sea shelf area and the Daotuo section of the semi-deep water slope area, no such thick mercury-rich stratum was reported. To explain this problem, comprehensive analyses were performed mainly focused on mercury and its isotopes, combined with total organic carbon (TOC), total sulfur (TS), and major and trace elements. The results show that the Hg content of all samples of the Datangpo Formation in the Xiangtan section is highly correlated with TOC and TS. Among them, the sandstone and Mn-ore units (Interval I) at the bottom are low in mercury content (19.78 ∼ 297.38 ppb), TOC and TS content, with the mercury isotope of Δ199Hg close to 0 ‰ (0.02 ∼ 0.19‰, with 0.07‰ on average), which is relatively lower in the whole section. The black shale in the middle (Interval II) and upper parts (Interval III) of the section has high mercury contents (121.00 ∼ 721.58 ppb) and high TOC and TS contents, with positive Δ199Hg values (0.20‰ on average). This reveals that a large dissolved organic carbon (DOC) reservoir existed in the deep-water area during the Datangpo period. The release of organic carbon and Hg is mainly controlled by the redox environment and is not affected by paleoproductivity. The persistent high Hg value and positive Δ199Hg values can trace the existence of this DOC reservoir. Additionally, the sandstone-black shale-siltstone sequence of the Datangpo Formation from bottom to top shows a complete interglacial climate pattern characterized by initial warming followed by cooling, as well as a rise and subsequent fall in sea level. This study will help us to establish a more complete Hg cycle and redox process for the Datangpo period in the Nanhua basin. [ABSTRACT FROM AUTHOR]

Ice margin remains are of great significance for reconstructing climatic conditions in certain areas and time periods and in delineating permafrost boundaries. In the middle and upper reaches of the Qingshui River in Ningxia (36°22′5"N~36°25′53"N), a group of ice margin remnants of the highest glacial period of the last glacial period were found, including ancient ice wedges and thaw folds. Among them, 4 ancient ice wedges were found in the section of Tangbao Village, which were wedge-shaped in shape, wide above and narrow below; The wedge wall is not straight, and the fissures formed before the collapse of the strata around the wedge; The wedge is filled with fragments of the surrounding formation and brownish-red silt. Two layers of continuous thaw folds were found in the section of Sanchahe Village, and the axial surface of the folds tended to be productionally chaotic and had no uniform orientation; There is no significant thickening or thinning of the fold shaft, no interlayer sliding occurs in the wing part, and the top of the fold layer is not developed and truncated; Interlayer folds are not developed interstitial backflush or positive rupture. Dating and measuring according to photoreflection14C dating results showed that paleogyne wedges formed at 14.06-11.45 ka B.P. and thaw folds formed at 13 500-11 570 a B.P. Affected by the Neo-Nymph event, the Qingshui River Basin developed a large area of permafrost at the peak of the last glacial period, with a distribution range of at least 36°22′5"N south. Since the last glacial period of northern China, the western section of the southern boundary of the permafrost can be pushed southward at least about 52′ (radial distance of about 97 km). This finding provides new evidence for the demarcation of the southern boundary of permafrost in northern China during the last glacial period [ABSTRACT FROM AUTHOR]

As a result of the influence of plate movement, the upper reaches of Jinsha River have strong geological tectonic activities, large topographic fluctuations, and complex climate characteristics, which result in the frequent occurrence of landslide disasters. Hence, there is the need to carry out landslide susceptibility mapping in the upper reaches of Jinsha River to ensure the safety of local people's property and the safe exploitation of hydraulic resources. In this study, InSAR technology and a field geological survey were used to map the landslides. Then, the curvature watershed method was used to divide the slope units. A conditioning factor system was established, which can reflect the characteristics of the rapid uplift and vertical distribution of rainfall in the special geological environment of the study area. Finally, logistic regression, random forest, and artificial neural network models were used to establish the landslide susceptibility model. The results show that the random forest model is optimal for the landslide susceptibility mapping in this area. Additionally, the area percentages of the very low, low, moderate, high, and very high susceptibility classes were 40.13%, 20.06%, 13.39%, 12.55%, and 13.87%, respectively. Based on the analysis of the landslide susceptibility map, we suggest that the landslide geological hazards resulting from the rapid uplift of the Tibetan Plateau and the significant decrease in sea level during a glacial period in the upper reaches of Jinsha River are controlled by the double disaster effect of the geodynamic system. Consequently, this study can guide local prevention and mitigation. [ABSTRACT FROM AUTHOR]

Understanding phylogeography, demographic dynamics as well as evolutionary forces of agricultural pests can enhance our understanding of their distribution dynamics, which is critical for developing effective control strategies. The pink rice borer (PRB), Sesamia inferens (Walker), is a destructive pest of rice that is widely distributed in Asia; however, little is known regarding its phylogeography and evolutionary history. In this study, we investigated the genetic diversity, population genetic structure and demographic history of the PRB at the scale of its whole distribution in China. Both mitochondrial and microsatellite datasets indicated that PRB individuals exhibit high levels of genetic diversity. Two large phylogeographic clusters were identified, corresponding to Northern and Southern China regions, respectively. The glacial events during the penultimate glacial period likely led to the separation of these two clusters, and parts of Northern and Southern China areas acted as independent refugia for PRB during glacial period. Two microrefugia in the Sichuan Basin and Yunnan‐Guizhou Plateau were also identified, and the PRB from Sichuan Basin could be one of the ancestral sources for PRB individuals from the Northern China lineage. Our study not only provides information that has implications for refugia identification, but also provides an example on how to reveal the phylogeography, demography history and evolutionary forces of an agriculture pest. [ABSTRACT FROM AUTHOR]

Termination of the Marinoan global glaciation (650–635 million years ago, Ma) was immediately followed by the diversification of eukaryotes and possible occurrence of animals, suggesting the potential linkage between biological evolution and global glaciation. It is proposed that the post-glacial eukaryote evolution might have been triggered by environmental stress imposed by the extreme pan-glacial condition. However, how life survived through the global glaciation remains speculative. Neither is known about the habitability when the ocean was completely or mostly frozen. In this study, we explore the marine carbon and sulfur biogeochemical cycles during the Nantuo (Marinoan) glaciation (650–635 Ma) in South China. Both organic carbon (δ13C org) and pyrite sulfur isotopes (δ34S py) show significant stratigraphic variations, suggesting active biogeochemical cycles in the pan-glacial condition. By coupling both δ13C org and δ34S py data, we develop numerical models to constrain marine productivity and redox conditions during the Nantuo glaciation. The marine primary productivity showed a sharp decline in the onset of glaciation and recovered right before the cap carbonate precipitation. An episodic recovery of primary productivity was observed in the non-glacial interval between the two glacial episodes. In contrast, the marine productivity was still suppressed in initial deglaciation, during which the continental weathering was intense, presumably indicating high atmospheric CO 2 level and low seawater pH value. The final recovery of marine primary productivity occurred in the topmost of Nantuo Formation, when the weathering intensity was already low. Therefore, the active biogeochemical cycle implies a sustained habitability, warranting the survivorship in the pan-glacial ocean, while the persistently low and delayed recovery of marine productivity might have imposed environmental stress for tens of million years, paving the way for the evolution of animals. [ABSTRACT FROM AUTHOR]

The phylogeography of the Kaloula genus in East Asia is still poorly understood. One of the difficulties is the absence of fossils to corroborate molecular dating estimates. Here, we examined the mitochondrial structure of Kaloula spp. in East Asia and focused on the impact of glaciations on the northernmost species: Kaloula borealis. We determined the phylogenetic relationships, molecular dating, and genetic connectivity assessments within the genus from 1211 bp of concatenated mitochondrial 12S and 16S. The relaxed clock analyses reveal the emergence of Kaloula spp. common ancestor in East and Southeast Asia between the Eocene and Oligocene, c. 38.47 Ma (24.69–53.65). The genetic diversification of lineages then increased on the East Asian Mainland during the Lower Miocene, c. 20.10 (8.73–30.65), most likely originating from the vicariance and radiation triggered by the orogeny of the Qinghai–Tibetan Plateau. Later, the dispersal towards the North East Asian Mainland during the Upper Miocene drove the population diversification of K. borealis c. 9.01 Ma (3.66–15.29). Finally, the central mainland population became isolated following orogenesis events and diverged into K. rugifera during the Pliocene, c. 3.06 Ma (0.02–10.90). The combination of population genetic and barrier analyses revealed a significant genetic isolation between populations of Kaloula spp. matching with the massive Qinling–Daba Mountain chain located in south‐central China. Finally, we highlight a young divergence within the Eastern Mainland population of K. borealis, possibly attributed to refugia in south eastern China from which populations later expanded. [ABSTRACT FROM AUTHOR]

In recent years, the evolution of the magnetic flux lobes in terms of location and intensity has been attributed to paleosecular variation of the geomagnetic field, reflecting outer‐core fluid convection close to the core‐mantle boundary. However, most results were based on observational data for the past 400 years supplemented by sparse archeomagnetic studies with data for approximately 3 kyr. In this paper, we construct a relative paleointensity (RPI) record and an inclination record spanning the past ∼90 kyr based on two cores from Tengchong Qinghai Lake (Yunnan Province, China), a closed crater lake that formed in the late Pleistocene. The evolution of flux lobes and the non‐dipole field can be assessed on a much longer time scale. Although the concentration and domain state of magnetic grains in the cores vary significantly, the RPI record is still representative of geomagnetic field features in the region of Yunnan Province, China. The contrasting trends in RPI with the records for eastern China since the late Holocene indicate the southeastward migration of the Siberian flux lobe. During the last glacial period, the RPI records of Tengchong Qinghai Lake and the North Atlantic Ocean show opposite trends, denoting the diverse and strong influence of the two flux lobe systems. The strong reverse flux lobe in the North Atlantic Ocean strengthened the non‐dipole field, while the weak normal flux lobe in Tengchong weakened the non‐dipole field. Plain Language Summary: Earth's magnetic field is composed of two main field components: a dipole field and a non‐dipole field. Although the non‐dipole field constitutes a minor component of the geomagnetic field, its variations in strength and location over different time scales have a significant influence on the surface expression of the geomagnetic field. The flux lobes arising from the fluid convection at the boundary between the core and mantle may produce the main components of the non‐dipole field. In recent years, the distribution of magnetic flux has been discussed based mainly on instrumental data and archeomagnetic data spanning a few kyr, which limits our understanding of flux lobe evolution on a much longer time scale. In this paper, we reconstruct a relative paleointensity (RPI) and an inclination records over the past ∼90 kyr from sediments of a closed volcanic lake in Tengchong, Yunnan Province, China. The results show that the RPI in the Tengchong area differs from the records for eastern China in the Holocene and from the records in the North Atlantic Ocean during the last glacial period. We conclude that a flux lobe may have played an important role in the non‐dipole field in the Tengchong and in the North Atlantic Ocean. Key Points: High‐resolution paleosecular variation records, including relative paleointensity (RPI) and inclination for the past 90 kyr, are derived from sediments in a closed lake in ChinaThe Holocene RPI trend obtained differs from records from records from eastern China, indicating the movement and intensification of the Siberian flux lobeThe opposing RPI patterns from the lake and the North Atlantic Ocean during the last glacial period indicate the influence of flux lobe systems on the non‐dipole field [ABSTRACT FROM AUTHOR]

Background: Refugia is considered to be critical for maintaining biodiversity; while discerning the type and pattern of refugia is pivotal for our understanding of evolutionary processes in the context of conservation. Interglacial and glacial refugia have been studied throughout subtropical China. However, studies on refugia along the oceanic–continental gradient have largely been ignored. We used a liana Actinidia eriantha, which occurs across the eastern moist evergreen broad-leaved forests of subtropical China, as a case study to test hypotheses of refugia along the oceanic–continental gradient and 'oceanic' adaptation. Results: The phylogeographic pattern of A. eriantha was explored using a combination of three cpDNA markers and 38 nuclear microsatellite loci, Species distribution modelling and dispersal corridors analysis. Our data showed intermediate levels of genetic diversity [haplotype diversity (hT) = 0.498; unbiased expected heterozygosity (UHE) = 0.510] both at the species and population level. Microsatellite loci revealed five clusters largely corresponding to geographic regions. Coalescent time of cpDNA lineages was dated to the middle Pliocene (ca. 4.03 Ma). Both geographic distance and climate difference have important roles for intraspecific divergence of the species. The Zhejiang-Fujian Hilly Region was demonstrated to be a refugium along the oceanic–continental gradient of the species and fit the 'refugia in refugia' pattern. Species distribution modelling analysis indicated that Precipitation of Coldest Quarter (importance of 44%), Temperature Seasonality (29%) and Mean Temperature of Wettest Quarter (25%) contributed the most to model development. By checking the isolines in the three climate layers, we found that A. eriantha prefer higher precipitation during the coldest quarter, lower seasonal temperature difference and lower mean temperature during the wettest quarter, which correspond to 'oceanic' adaptation. Actinidia eriantha expanded to its western distribution range along the dispersal corridor repeatedly during the glacial periods. Conclusions: Overall, our results provide integrated evidence demonstrating that the Zhejiang-Fujian Hilly Region is a refugium along the oceanic–continental gradient of Actinidia eriantha in subtropical China and that speciation is attributed to 'oceanic' adaptation. This study gives a deeper understanding of the refugia in subtropical China and will contribute to the conservation and utilization of kiwifruit wild resources in the context of climate change. [ABSTRACT FROM AUTHOR]

Glacial erosion has long been recognized as a significant factor contributing to continental denudation during the Ediacaran Period, consequently leading to geochemical perturbations and biotic evolution in marine environments. However, the role of Ediacaran glaciation in the oceanic geochemical perturbations remains controversial due to ambiguous geochronological correlations and unresolved paleogeographic and tectonic settings. A total of 45 Ediacaran glacial records have been reviewed and categorized into four Ediacaran glaciations: Gaskiers (581–579 Ma), Fauquier (ca. 571 Ma), Bou-Azzer (ca. 565–560 Ma), and Hankalchough (ca. 562–551 Ma) glaciations. Of these glacial records, 53% have been reported in the Avalonian–Cadomian and Altaids accretionary orogenic belts, recognized as representing Cordilleran-type mountain ice sheets (CMISs). This study reports an Ediacaran glaciation in the southern Altaids, NW China, with 18 glacial and non-glacial facies and 1173 new U-Pb-Hf data from detrital zircons. The maximum ages of deposition based on detrital zircons from the Ediacaran to Lower Cambrian strata indicate an age range from 591.1 to 561.9 Ma for the glacial and deglacial sequences. The glacial sequences consist mostly of proglacial marine facies associated with ice-rafted diamictites and turbidite facies. The unimodal detrital zircon feature of these proglacial facies suggests that the glaciation center was located proximal to a ca. 644 Ma magmatic arc. A statistical comparison of detrital zircon facies was conducted on a regional Ediacaran dataset compiled from 12,291 U-Pb-Hf data points from the Altaids, Siberia, Tarim, North China and South China Cratons. The result suggests the presence of CMISs extending from Beishan to Yili Tianshan and Kyrgyz Tianshan along an active margin of the Paleo-Asian Ocean (PAO). The provenance shift and exhumation of a ca. 967 and 2469 Ma granitic basement suggests that erosion by the Ediacaran ice sheets provided a greater contribution to the terrestrial influx and geochemical perturbations in the late Ediacaran oceans compared with other glacial and tectonic events. [ABSTRACT FROM AUTHOR]

The Greater Khingan and Yanshan mountain ranges in northern China not only constitute a significant physical obstacle to the northward movement of monsoon circulation, but also represent a natural barrier for human migration and cultural interactions between in-migrating Paleolithic populations and those indigenous to East Asia during the Late Pleistocene. We dated two Paleolithic sites, Yangzhuangxishan and Taiziling, located in the southern piedmont of the Yanshan Mountains with artifacts typified by simple core and flake technology associated with foraging populations, to ∼39–29 ka and ∼ 52–47 ka respectively, using the optically stimulated luminescence dating method. Our results indicate that northern China as far south as the Yanshan Mountains was occupied mainly by autochthonous East Asian Paleolithic populations using a core and flake lithic technology, although during this period Initial Upper Paleolithic (IUP) modern humans and Mousterian populations dispersed into East Asia. By synthesizing and integrating the ages of Northeast Asian Paleolithic sequences during the last glacial period (ca. 70–10 ka), we analyzed spatio-temporal variations in Late Pleistocene human populations during relatively cold stadial events (MIS 4 & 2) and warmer interstadials (e.g., MIS 3), revealing an "ebb and flow" pattern for migrations of Western IUP/Mousterian populations and indigenous core and flake technology populations in East Asia corresponding to the advance and retreat of the East Asian monsoon regime. The subsequent extremely cold climate phase engendered a major population shift during the Last Glacial Maximum (ca. 26.5–19 ka) which drove the reduction of both these Paleolithic populations, but afterward facilitated the emergence and rapid dispersal of microlithic technologies in East Asia. The peoples associated with microlithic technologies achieved their maximum geographical extent after the Bølling-Allerød Late Glacial interstadial event (ca. 14.7–12.9 ka) and then gradually decreased, perhaps due to the development of agriculture after ∼13 ka with concomitant increasing settlement stability. • Two Paleolithic sites on the Yanshan Mountains were dated using OSL method. • Migrations of Western and indigenous populations correspond to monsoonal fluctuations. • The cold LGM climate engendered a major population shift. • Microblade populations decreased after ∼13 ka due to initiation of agriculture. [ABSTRACT FROM AUTHOR]

The correlation between Neoproterozoic tectonics, paleoenvironment and early life are crucial for understanding the evolution of the Earth's habitability. The Yangtze Block preserves plenty of essential records to investigate these topics. The early Tonian tectonics of the Yangtze Block was characterized by exterior spreading to its west and north, and coeval interior subduction along its eastern margin, resulting in the passive continental marginal basins on the western and northern margins, and arc-related basins along the eastern margin. In the middle Tonian, the long-term exterior subduction-accretion on the west and north resulted in numerous arc-type igneous rocks and associated clastic deposits. In the east, the continuous interior subduction generated an active continental margin, with back-arc and retro-arc basins filled with volcanic and clastic rocks, and finally led to the collision between the Yangtze and Cathaysia blocks at ca. 820 Ma. Some typical Neoproterozoic microfloras were flourishing. During the late Tonian, the exterior subduction generated the arc-related volcanic basins in the western and outer northern margins, while the interior post-collisional rifting resulted in a rift basin in the eastern margin, filled by shallow-marine to bathyal facies sediments. Influenced by the marginal volcanism, the paleoclimate was warm and humid in the early period, and transition to rather cold and dry in the late period. The microfloras remained the dominant paleontological taxonomy, but some macroalgal fossil fragments appeared. In the Cryogenian, along with termination of the exterior subduction, most parts of the Yangtze Block entered an extensional tectonics. Together with global paleoclimate cooling, the various tectonic backgrounds and paleogeographical frameworks of individual margins accumulated different glacial-interglacial sequences on the eastern, northern and western margins. These multi-stage deposits record paleoclimate cycles of cold-dry glacial periods and warm-humid interglacial periods. Subject to more extreme paleoclimate and paleoenvironment, early life was still dominated by microfloras (Monosphaeritae and Prismatomorphitae of Sphaeromorphida) with minor macroalgal fossil fragments. During the Ediacaran, the entire Yangtze Block evolved into an extensional-subsidence tectonics, with carbonate platform (inner shelf and outer shelf) to abyssal-bathyal (slope-basin) facies gradually developing from northwest to southeast. Episodic atmospheric and oceanic oxygenation events resulted in positive shifts in paleoclimate and paleoenvironment. The advantageous conditions induced several global Ediacaran biotas on the Yangtze Block, which are known as the prologue and first phase of the Cambrian explosion, including the Lantian, Weng'an, Miaohe, Shibantan and Gaojiashan biotas. The transition from the Ediacaran to Cambrian constitutes a critical inflection point in geological history, marking a co-evolution of organisms and paleoclimates that flourished by mutations. Appropriate external conditions made the early life further radiate, and the second and third phases of the Cambrian explosion were unveiled. They are represented by the Meishucun small shelly fossils (SSFs) on the western margin, and the Chengjiang biota and the contemporaneous Qingjiang biota on the western and northern margins of the Yangtze Block, respectively. Such manifestations indicate that the Cambrian explosion in the Yangtze Block was most likely related to the Neoproterozoic subduction and continental arcs, which could provide sufficient nutrients for the later early life radiation. [Display omitted] • Coevolved Neoproterozoic tectonics, paleoenvironment and early life occurred in Yangtze Block. • Early to middle Tonian exterior and interior tectonics lead to mainly active environments. • Late Tonian rift basins document a gradual cooling climate and microflora-dominated organisms. • Cryogenian deposits record multi-stages of cold-dry glacial and warm-humid interglacial cycles. • Ediacaran subsidence and oxygenation induced positive environment shift and bioradiation. [ABSTRACT FROM AUTHOR]

A multidisciplinary fieldwork and research project was recently begun at the Yangshang site (220–140 ka), a late Early Paleolithic locale in the western Chinese Loess Plateau. 1696 lithic artifacts and 337 faunal remains were recovered during the excavation. Sedimentological and paleoenvironmental investigations indicate the site preserves a relatively long and minimally disturbed archaeological sequence associated with paleoenvironmental changes during MIS 7–6. A detailed techno-typological analysis of Yangshang's lithic assemblages was undertaken to examine the influence of glacial cycles on late Middle Pleistocene hominin technological strategies in the western Chinese Loess Plateau. The results show that while the Yangshang site is dominated by quartz-based core/flake assemblages typical of most Early Paleolithic sites in North China, the lithic assemblages provide evidence that different provisioning systems existed during the penultimate glaciation. We argue that these shifts reflect changes in land use and mobility that were tied to climate change. Our results suggest that theoretically informed statistical analyses of so-called unchanging and crude lithic technology can yield meaningful evidence for behavioral shifts. [ABSTRACT FROM AUTHOR]

Focusing on the Shuixiakou Section (Xikou area, Zhen'an County, Shaanxi Province, southeastern Qinling region, China), the Roadian-Wordian conodonts are investigated. More than 2 000 conodont elements including 6 genera and 14 species have been obtained. Based on these materials, the Guadalupian Jinogondolella nankingensis and J. aserrata zones have been recognized. The Roadian-Wordian boundary is tentatively defined by the first occurrence of J. aserrata in the lower part of Unit III in the Shuixiakou Formation. The sedimentary succession of Xikou area records similar sea-level changes to those observed in Laibin area (South China). The 40 m-thick bioclastic limestone of Unit IV in this section can be correlated with the reefs of Bed 114 in Laibin area. A temperature drop indicated by δ18Oapatite values suggests this Wordian interval coincides with a period of glaciation and global regression. [ABSTRACT FROM AUTHOR]

To reveal the historical dynamics of the population and existing genetic structure, maternal chloroplast DNA fragments(psbA-trnH, psbI-psbK and psbJ-petA)were used to study the phylogeography of Prinsepia uniflora, a kind of endemic plant distributed in the Loess Plateau. The results were as follows:(1)Total genetic diversity of P. uniflora was high(HT = 0.796), but genetic diversity within species was low(HS= 0.276);(2)The molecular variation analysis(AMOVA)showed that there was a high genetic differentiation within P. uniflora(FST = 0.674), and the genetic variation was mainly between populations(67.4%);(3)Mismatch analysis and MaxEnt based ecological niche simulation results in different historical periods showed that although the core suitable range of P. uniflora did not change much, population still expanded to some extent after the end of the Last Glacial Maximum(LGM). Our study indicated that, like most of the plant groups distributed in the northern regions of China, P. uniflora probably responded to the Quaternary climatic fluctuations by taking refuge nearby or in situ during the glacial period and locally recolonizing in following post-glacial period. [ABSTRACT FROM AUTHOR]

In East Asia, genetic divergence is usually considered to be correlated to different floristic regions, however, subtropical-tropical divergence is largely ignored, compared to widely explored temperate-subtropical divergence. Lindera aggregata (Lauraceae), a dominant species in South-East China was selected to address this issue. Fifteen low-copy nuclear genes (LCGs) and four chloroplast DNA (cpDNA) fragments were used to detect its evolutionary history. In LCGs, STRUCTURE and dated Bayesian phylogeny analyses detect distinct subtropical-tropical divergence since late Pleistocene. Approximate Bayesian calculation (ABC) further supports the distinct subtropical-tropical divergence, and close related Taiwan and South China populations are diverged at the last interglacial. Isolation by distance, isolation by environment and isolation by resistance analyses suggest the current climatic difference rather than geographical distance contributes to the genetic differentiation. Principle component analysis shows populations of tropical cluster occur in warmer area with higher precipitation. Ancestral area reconstruction based on Bayesian phylogeny indicates that ancestral L. aggregata populations are distributed in tropical region. In cpDNA, although unique haplotypes are found in tropical region, distinct subtropical-tropical divergence is absent. In conclusion, distinct late Pleistocene subtropical-tropical divergence of L. aggregata is triggered by climate. It is likely that L. aggregata is originated in Southwest-South China and experienced hierarchical dispersal from south to north. The South China Sea land bridge has dual role in connecting or isolating Taiwan and mainland populations since the last glaciation. [ABSTRACT FROM AUTHOR]

The Last Glacial Maximum (LGM; 21 ka BP) was the most recent glacial period when the global ice sheet volume was at a maximum. Therefore, the LGM can be used to investigate atmospheric dynamics under a climate that differed significantly from the present. This study quantitatively compares pollen records of boreal summer (June–July–August) precipitation with the PMIP3 LGM simulations. The data-model comparison shows an overall agreement on a drier than pre-industrial East Asian summer monsoon (EASM) climate. Nevertheless, 17 out of 55 records show a regional precipitation increase that is also simulated over the additional land mass area due to sea level drop. The thermodynamic and dynamic responses are analyzed to explain a drier LGM EASM as a combination of these two antagonistic mechanisms. Relatively low atmospheric moisture content was the main thermodynamic control on the lower LGM (relative to pre-industrial levels) EASM precipitation amounts in both the reconstructions and the models. In contrast, two dynamic processes in relation to stationary eddy activity act to increase EASM precipitation regionally in records and simulations, respectively. Precipitation increase in records is explained by dynamic enhancement of the horizontal moisture transport, while dynamic enhancement of the vertical moisture transport leads to simulated precipitation increase over the specific region where landmass was exposed during LGM along continental coastlines of China due to significant drop in sea level (relative to pre-industrial levels). Overall, the opposing effects of thermodynamic and dynamic processes on precipitation during the LGM provide a means to reconcile the spatial heterogeneity of recorded precipitation changes in sign, although data-model comparison suggests that the simulated dynamic wetting mechanism is too weak relative to the thermodynamic drying mechanism over data-model disagreement regions. [ABSTRACT FROM AUTHOR]

Extensive loess deposits exist in the Western Qinling Mountains (WQM), which constitute the transition zone between the Tibetan Plateau and the Chinese Loess Plateau (CLP). These deposits are one of the most important terrestrial archives regarding past dust activity and environmental changes in East Asia; however, they remain insufficiently known and poorly understood. Herein, we conducted detailed quartz optically stimulated luminescence dating and multi‐proxy analysis on the Zhouqu loess sequence. Our results show that the loess on the high terrace of the Bailong River started to accumulate by at least ~60 ka. The mass accumulation rate (MAR) in Zhouqu significantly varied during the Last Glacial period. The Marine Isotope Stage (MIS) 3 MARs were relatively high and stable. The highest MAR occurred in MIS 2, with peak MARs during 25–19 ka, and it decreased with rapid changes during the Holocene. The discrepancy in the MARs of the WQM loess since the Last Glacial period compared with the rates in the CLP may imply different dust deposition processes in the WQM. The reconstructed palaeoenvironmental records indicate climate changes with warm‐moist climate patterns and low dust flux in interglacial periods and cold‐dry conditions with high dust flux in glacial periods, consistent with those on the CLP. The results contribute to better understanding of the linkages between dust accumulation and climate change in the WQM area. [ABSTRACT FROM AUTHOR]

The Tarim Craton, China, records several significant events in the history of the Rodinia supercontinent, including Neoproterozoic glaciations and rift evolution. In this study, we use geochronological, geochemical, and geophysical data from the Aksu region, northwest Tarim Craton, to investigate the rifting history and three discrete Cryogenian glaciations in the Tarim Craton. A total of 268 concordant zircon U–Pb ages were obtained from three samples in the lowermost unit of the Cryogenian Xifangshan Formation. These ages define four Neoproterozoic populations of ca. 975–900, 885–810, 795–755, and 740–720 Ma, which reflect magmatic events in the Rodinia supercontinent. The age of the Xifangshan Formation is constrained by two maximum depositional ages of 739 ± 9 Ma and 719 ± 7 Ma, suggesting a stratigraphic correlation with the Cryogenian Baiyisi Formation in the Kuruktag region, northeast Tarim Craton. Field and geochemical evidence identify three discrete Cryogenian glaciations in the Aksu region, which are the Xifangshan, Qiaoenbrak, and Youermeinark glaciations that can be chronologically correlated with the Baiyisi, Altungal, and Tereeken glaciations in the Kuruktag region, respectively. The northern rift basin in the Aksu region formed at ca. 740 Ma and is filled by a thick Cryogenian volcanic–sedimentary succession. This rift basin gradually expanded to entire northern Tarim Craton, with sediments being unconformably deposited on underlying formations. Although large-scale deformation occurred in the late Ediacaran, corresponding to the Pan-African orogeny, the Aksu rift depocentre was covered with a series of deep-water rocks in the Early Cambrian and Ordovician. [ABSTRACT FROM AUTHOR]

The Ediacaran-Cambrian transition is recognized as a warm period. However, glaciations have been reported in many paleocontinents worldwide during this transition, including the Luoquan glaciation in Northern China. The type of glacier remains unclear, and there are still uncertainties regarding the differences and similarities between the Luoquan glaciation and other Ediacaran glaciations, which restrict global comparison of glaciation characteristics. Research on sedimentary characteristics and succession of eight sections of the Luoquan and Dongpo formations in western Henan Province in the southern North China Craton shows that from north to south, the Luoquan and Dongpo formations show three vertical facies associations spatially, indicating an obvious sedimentary environment evolution of subglacial-periglacial-glaciomarine-shallow marine, namely, from the subglacial lodgement to the periglacial outwash fan and permafrost, then to the proximal glaciomarine grounding-line fan and iceberg rainout to the distal glaciomarine ice-rafted deposits, and finally to the normal shallow sea. The spatial evolution of sedimentary environment indicates that the Luoquan glaciation in western Henan Province was a large ice sheet that extended from land to the sea and was not completely frozen but partially melted during warm periods, and temporary open-water conditions existed. Further comparison shows that although the number, frequency and global characteristics have not yet been determined, the global Ediacaran glaciations also show dynamic evolution characteristics from continental to marine glaciers, which is similar to the evolution mechanism of ice sheet during the snowball Earth, and also not indicative of hard snowball Earth pattern of complete ice cover. • Four facies associations of Luoquan glaciation in western Henan province on the southern margin of NCC are recognized. • The sedimentary evolution of Luoquan glaciation is from subglacial to periglacial, then to glaciomarine and shallow sea. • The Luoquan glaciation is a warm-based ice-sheet that extends from continent into the sea, rather than a mountain glacier. [ABSTRACT FROM AUTHOR]

Guanyindong Cave is one of most important Palaeolithic sites in southwestern China, due to its presence of the earliest Levallois artifacts in East Asia, which was dated to two discrete periods at ∼160–170 thousand years ago (ka) and ∼70–80 ka, respectively, based on optical dating of the artifact-bearing sediments from the west entrance of the cave (Hu, et al., 2019a). There were five excavation pits at Guanyindong during the initial excavation seasons in 1960s, all of which have yielded abundant stone artifacts and fauna fossils. However, in contrast to the excavation pits at the west entrance whose chronology and lithic industry were intensively studied, the chronological frameworks of the excavation pits inside the cave chambers have not been established. Here we report optical dating results of sediment samples taken from two of the pits inside the cave (Profiles 2A and 3). We established Bayesian age models for the two profiles based on our new optical ages and the U-series ages obtained in previous studies. Our results indicate that the group B deposits in the main chambers of the cave accumulated between ∼200 ka and ∼100 ka. The chronology of the deposits from the inner chambers, together with those from the west entrance, provided a new age constraint for the Levallois artifacts from the site and suggested that hominins occupied the cave from ∼180 ka to ∼80 ka, spanning a full glacial and interglacial period (from MIS 6 to MIS 5). • Comprehensive luminescence dating results of accumulation and occupation of Guanyindong cave. • The Bayesian Hierarchical Age Model was applied for dating sediments with post-depositional disturbance. • The new dating results confirm the early utilization of the Levallois concept in East Asia from 180 to 80 ka. [ABSTRACT FROM AUTHOR]

Distinct moraine complexes are well-preserved at the headwaters of the Requ River valley on the southern slope of Bujia Gangri, the largest center of modern glaciation in the eastern Tanggula Mountains in western China. Dating these moraines is an important step in understanding glacial history, palaeoclimate, and landscape evolution in this region. Surface exposure dating using 10Be was done on twenty-three rock samples from large granitic boulders embedded in moraine crests were collected from the Yongqu River valley and the Daxiong River valley, two glaciated valleys at the headwaters of the Requ River valley. The moraines (M W1 and M E1) closest to the current glaciers in the west (main) and east (hanging) valleys of the Yongqu River valley were dated to 203 ± 51 a (n = 4) and 162 ± 58 a (n = 3); the inner four end moraines (M W3 – 1) and outer ones (M W3 – 2) of the third moraine complex (M W3) in the main valley date to 16.8 ± 1.8 ka (n = 3) and 20.7 ± 1.3 ka (n = 2); end moraines (M E2) near the mouth of the east valley and a high lateral moraine (M EL) on its east side date to 18.9 ± 3.0 ka (n = 4); and a high lateral moraine in the Daxiong valley (M DXL) dates to 18.6 ± 1.3 ka (n = 3). The dating results indicate that these moraines were formed during the Little Ice Age (LIA), the Heinrich 1 (H1) event period, and the global Last Glacial Maximum (LGM G). These glacial events are synchronous with those across the Tibetan Plateau (TP) and its surrounding mountains. Combining the palaeoclimatic and palaeoenvironmental proxies in the TP and its surroundings, we infer that the cooling during the LIA, H1, and LGM G was a main control for these glacial advances. • A preliminary 10Be chronological framework since LGM G has been established in the eastern Tanggula Mountains. • Cooling during LIA, Heinrich 1 and LGM G glacial periods is the main determinant for palaeoglacier fluctuations. • A teleconnection between the North Atlantic cooling and palaeoglaciations since LGM G in the TP has been established. [ABSTRACT FROM AUTHOR]

1. Identifying the macro‐scale patterns and the underlying mechanisms of species richness are key aspects of biodiversity‐related research. In China, previous studies on the mechanisms underlying insect richness have primarily focused on the current ecological conditions. Therefore, the impact of historical climate change on these mechanisms is less well understood. 2. Here, we use members of the Delphacidae family to evaluate the relative impact of the current environmental conditions and that of the Last Glacial Maximum on total species richness and endemism. Total species richness and endemic species richness were summed in 1° × 1° grid cells that the insects occupied. Generalised linear models, simultaneous autoregressive models, and random forest models were used to assess the effects of different environmental factors on total species richness and endemism. 3. The two patterns of species richness are jointly regulated by the current environment and the Last Glacial Maximum, but their key determinants differ. Winter coldness and the temperature annual range strongly affected the total species richness, but temperature variation during the Last Glacial Maximum also played an important role in the development of species richness. The distribution of endemic species was most strongly affected by the Last Glacial Maximum temperature change. 4. The studies confirm that historical climate change contributes to patterns of insect species richness, particularly patterns of endemism. Considering that China was mildly affected by the last glacial period, we propose that the incorporation of historical climate data into such studies will provide a better understanding of the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Local adaptation is particularly likely in invertebrate pests that typically have short generation times and large population sizes, but there are few studies on pest species investigating local adaptation and separating this process from contemporaneous and historical gene flow. Here, we use a population genomic approach to investigate evolutionary processes in the two most dominant spider mites in China, Tetranychus truncatus Ehara and Tetranychus pueraricola Ehara et Gotoh, which have wide distributions, short generation times, and large population sizes. We generated genome resequencing of 246 spider mites mostly from China, as well as Japan and Canada at a combined total depth of 3,133×. Based on demographic reconstruction, we found that both mite species likely originated from refugia in southwestern China and then spread to other regions, with the dominant T. truncatus spreading ~3,000 years later than T. pueraricola. Estimated changes in population sizes of the pests matched known periods of glaciation and reinforce the recent expansion of the dominant spider mites. T. truncatus showed a greater extent of local adaptation with more genes (76 vs. 17) associated with precipitation, including candidates involved in regulation of homeostasis of water and ions, signal transduction, and motor skills. In both species, many genes (135 in T. truncatus and 95 in T. pueraricola) also showed signatures of selection related to elevation, including G‐protein‐coupled receptors, cytochrome P450s, and ABC‐transporters. Our results point to historical expansion processes and climatic adaptation in these pests which could have contributed to their growing importance, particularly in the case of T. truncatus. [ABSTRACT FROM AUTHOR]

Generally, island populations are predicted to have less genetic variation than their mainland relatives. However, a growing number of studies have nevertheless reported exceptions, indicating that the relationships were impacted by several factors, for example, historical processes. In the present study, we chose a group of subtropical islands located in South China as the study system, which are quite younger and much closer to the mainland than most of the previous studied island systems, to test the hypothesis that in situ glacial survival contributes to high levels of genetic diversity in island populations. We conducted a comparison of genetic variation between 12 island and 11 nearby mainland populations of Mussaenda kwangtungensis using eleven nuclear microsatellite and three chloroplast markers, evaluated effects of the island area and distance to mainland on genetic diversity of island populations, and simulated the potential distribution over the past by ecological niche modeling, together with the genetic data to detect the role of islands during the glacial periods. The island populations displayed comparable levels of genetic diversity and differentiation with mainland populations, overall high levels of unique polymorphisms, and the greatest values of specific within‐population genetic diversity. No significant correlation was detected between genetic diversity of island populations and distance to mainland, as well as area of islands, except that allelic richness was significantly positively correlated with the area of islands. Nuclear microsatellites revealed two main clusters, largely corresponding to islands and inland populations, which divergence dated to a time of island formation by ABC analysis. Ecological niche modeling predicted a highly climatic suitability on islands during the last glacial maximum (LGM). Our results suggest that the islands have acted as refugia during the LGM and highlight the role of in situ glacial survival in maintaining high levels of genetic diversity of M. kwangtungensis in continental islands of subtropical China. [ABSTRACT FROM AUTHOR]

A large number of hominin fossil-bearing caves in South China have yielded evidence for the occupation of early modern humans during the Middle to Late Pleistocene. However, the geology of these caves and the paleoenvironmental context of human occupation remain poorly documented and understood. In this study, we obtained new ages yielded by MC-ICPMS uranium-series dating of speleothems from Zhiren Cave, Guangxi, where a partial early modern human mandible and 2 M have been recovered. The ages demonstrate that cave infilling of Zhiren Cave began at ~1 Ma, much earlier than the date previously suggested. Our dating results also suggest that fossils of anatomically modern human were deposited in Zhiren Cave during marine isotope stage (MIS) 6, between ~190 and ~130 ka, representing the oldest known anatomically modern human remains in East Asia. The cave's sedimentary processes and the paleoenvironmental changes were reconstructed based on detailed analyses of lithostratigraphy, grain-size, pollen assemblages and the chemical weathering intensity of the sediments inside Zhiren Cave. The results show that major climatic changes in the Middle Pleistocene led to the accelerated incision of local streams and the erosion of cave sediments by controlling the regional hydrological response during the Early to Middle Pleistocene. After ~300 ka, increased climatic contrasts between glacial and interglacial periods dominated the accumulation of sediments and the occupation of mammals and early modern humans in Zhiren Cave. Gradually desiccating climatic conditions and reduced forest cover during the penultimate glacial period (MIS 6) may have define a temporal window for the human occupation of Zhiren Cave, providing ideal environmental conditions. However, floodwater incursion and/or dense vegetation cover corresponding to a much warmer and wetter climate in the subsequent last interglacial (MIS 5) may have discouraged humans from further occupying Zhiren Cave. [ABSTRACT FROM AUTHOR]

It remains debatable whether slash-and-burn practices were adopted in rice cultivation by the Neolithic Kuahuqiao culture in the Ningshao Plain, one of the birthplaces of rice farming. Here, we established charcoal-based indices to reconstruct the history of fire and vegetation in the Ningshao Plain since the last glacial period. We collected representative modern vegetation and conducted combustion and fragmentation experiments to simulate fire and depositional processes, respectively. Charcoals from modern vegetation show clear morphological differences between herbaceous and woody plants. In particular, the length to width ratios (L/W) of herbaceous charcoals were systematically higher than those of woody charcoals, and the associated end-member values were 4.50 and 1.94, respectively. These values were then applied to sediment cores (KHQ-14/15) collected in proximity to the Kuahuqiao archaeological site. Results show that the amount of combusted herbaceous plants increased sharply after the Holocene, and the most remarkable rise occurred around 8550 yr B.P. This observation may reflect local environment (sedimentary and/or climatic) changes or small-scale early human activities. During the Kuahuqiao cultural period (8250−7450 yr B.P.), the relative abundance of woody charcoals increased, but the overall fire intensity decreased. This finding suggests that the Kuahuqiao farming was restricted to a small geographic area and large-scale slash-and-burn farming activities were not adopted. [ABSTRACT FROM AUTHOR]

Based on the authors’ study on the original-define ‘Xingmincun Formation of Sinian System’， the characteristics of the glacial period environment were found in the fine grain quartz sandstone in the bottom of Zhoujiawaizi section of Xingmincun Formation， such as ice-rafting dropstone and fine laminary structure. In the bottom and upper part of Zhoujiawaizi section there are ice crystal impression and hailstone traces and other moraine traces. The Wangjiatanzi shale section of the original-define Xingmincun Formation belongs to the shallow sea facies open shelf subfacies sedimentary environment， producing different species of the medusa-like fossil which belong to the Sinian system. The structure of the medusa-like fossils produced in this layer is simple and small and the formation time should be earlier than that of Ediacaran. The Gandaozi limestone section of Xingmincun Formation belongs to the internal carbonate deposit. In view of the above research results， the authors consider that the sedimentary environment of the Zhoujiawzi sandstone， Wangjiatanzi shale and Gandaozi limestone of the original-define Xingmincun Formation is obviously different. It is necessary for original division of Xinmincun Formation to be disintegrated and divided into Zhoujiawaizi Formation， the Wangjiatanzi Formation and the Gandaozi Formation in the upper series of the Nanhua System. It is beneficial to the comparison and study of lithostratigraphy units in the late Neoproterozoic in China. [ABSTRACT FROM AUTHOR]