Biogeochemistry of sedimentary organic matter in the Yongjiang River estuary in the southern part of Hangzhou Bay,China,since the Late Pleistocene

A sediment core(YJK19-02)collected from the southern outlet of Hangzhou Bay near the Yongjiang River estuary in East China was analyzed for grain size,lignin,bulk elemental composition,stable carbon isotope,and rare earth elements(REEs)to determine the sources and diagenesis of sedimentary organic matter(OM)of the estuary and adjacent areas since the Late Pleistocene.δ^(13)C values(-24.80‰–-23.60‰),total organic carbon/total nitrogen(TOC/TN)molar ratios(8.00–12.14),and light rare earth element/heavy rare earth element ratios(LREE/HREE=8.34–8.91)revealed the predominance of terrestrial sources of OM,mainly from the Changjiang(Yangtze)River.The lignin parameters of syringyl/vanillyl(S/V=0.20–0.73)and cinnamyl/vanillyl(C/V=0.03–0.19)ratios indicate the predominance of nonwoody angiosperms,and the vanillic acid/vanillin ratios[(Ad/Al)_(V)=0.32–1.57]indicate medium to high degrees of lignin degradation.An increasing trend ofΛ(total lignin in mg/100-mg OC)values from ca.14500 a BP to ca.11000 a BP reflected the increase in temperature during the Late Pleistocene.However,a time lag effect of temperature on vegetation abundance was also revealed.The relatively higher and stableΛvalues correspond to the higher temperature during the mid-Holocene from ca.8500 a BP to ca.4500 a BP.Λvalues decreased from ca.4000 a BP to the present,corresponding to historical temperature fluctuations during this time.Our results show that the vegetation abundance in the Yongjiang River Basin since the Late Pleistocene was related to the temperature fluctuation duo to climate change.

Palynological Evidence of Late Pleistocene Soft-sediment Deformation Event in the Northeastern Margin of the Tibetan Plateau

The northeastern margin of the Tibetan Plateau is the youngest part of the Tibetan Plateau where tectonic activity is intense and climate change is complex.In this study,combined with field investigations,we explored accelerator mass spectrometry 14C and optically stimulated luminescence dating and palynological analysis of the sedimentary sequence in the Qingshuihe Basin to explain the origin of soft-sediment deformation layer.Dating and palynological results from the Sanchahe section in the basin revealed a detailed history of vegetation variation and associated climate change from~18 to~5 ka BP.The results indicate that the permafrost developed at~18–11.7 ka BP,and the soft-sediment deformation structures formed at~11.7–5 ka BP.Together with the characteristics of the deformation(meter-scale,continuous symmetrical wave)and paleoclimate,we suggest that the soft-sediment deformation layer in the late Pleistocene was cryoturbated under climatic conditions.The discovery of a series of cryoturbations in the Qingshuihe Basin has further enriched the regional distribution of periglacial phenomena in the west of the Ordos Plateau,expanded the distribution range of periglacial phenomena,and provided evidence for exploring the temporal and spatial changes in permafrost in northern China at the end of the late Pleistocene.

A Middle Pleistocene Glaciation Record from Lacustrine Sediments in the Western Tibetan Plateau and Discussion on Climate Change

The Tibetan Plateau is an important area for studying global climate change,but the answers to many scientific problems remain unknown.Here,we present new information from the lacustrine sedimentary record in the western Tibetan Plateau,related to the third most-recent glaciations.Continuous sediment data,including sporopollen,particle size,total organic carbon,mass susceptibility,CaCO_(3),CaSO_(4),BaSO_(4)contents and chronological data,were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years ago.In comparison,the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic regions.In this study,we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago(from Matuyama to Brunhes).Indeed,the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future.

Late Pleistocene glaciation of the Hulifang Massif of Gongwang mountains in Yunnan Province

Late Pleistocene glaciation was restricted to only a few high mountains in eastern China. The Gongwang mountains constitute one of the typical places once glaciated. Geomorphic mapping of the area and the TL dating provides evidence for at least four distinct glaciations. YJT-Ⅰ glacial advance occurred about 100 ka BP and two TL absolute ages （101,100 ± 7780 a BP; 104,000± 8300 a BP） indicate this advance happened during the Penultimale Glaciation. The early stage glacial advance （YJT-Ⅱ advance） during the last glaciation occurred about 40,920 ± 3400 a BP. The last glacial maximum advance （YJT-Ⅲ advance） about 18-25 ka BP, which sustained by two TL ages （18,230 ±1420 a BP; 25,420 ± 2110 a BP）. The Penultimale and the early stage glaciations were more extensive and the last glacial maximum （LGM） and the late-glacial period （YJT-Ⅳ advance, 10 ka BP） were progressively less extensive. Correlated with the other mountains in eastern China, these glacial advances in the Gongwang mountains just like the advances in the western part such as Diancang mountains, Yulong mountains of Yunnan Province and the glacier series are more complete than the adjacent mid-latitude regions such as Taibai mountain and Taiwan mountains and are roughly representative of climate changes during the last glacial cycle in Yunnan Province.

Late Pleistocene aeolian activity in Haitan Island, Southeast China: Insights from optically stimulated luminescence dating of coastal dunes on marine terraces

The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive characteristics and are a critical archive for understanding climatic changes in the coastal areas of East Asia. The ages of the late Quaternary aeolian sand dunes from Haitan Island in the coastal area of South China are still in debate. In this study, three sets of marine terraces were identified in the northern region of Haitan Island. Aeolian dune sands are well preserved on the top of these terraces. Quartz Optically Stimulated Luminescence dating and the distribution of the formation ages demonstrated that the palaeo-dunes are deposits from the middle-late period of the Late Pleistocene(Q_3^(2-3)). The period may be divided into three stages, 100-90 ka, 70-60 ka, and 40-20 ka, in which the palaeo-dunes of the first two stages are more widespread and were formed separately during a low-sea level period of the Marine Isotope Stages 5 b and 4. Several depositional palaeo-flood event records were preserved during the last stage due to the increasing gradient of mountain gullies formed during the Last Glacial Maximum.

Environmental evolution in the salt-water intrusion area south of Laizhou Bay since late Pleistocene

The south coastal plain of Laizhou Bay is one of the typical salt-water intrusion areas in China, the occurrence and development of which was closely related with the palaeoenvironment evolution. Systematic analyses of pollen, foraminifera and grain size composition based on ^14C and luminescence dating from two sediment cores were performed for the purpose of understanding the salt-water intrusion in the coastal plain of Laizhou Bay from the perspective of environmental evolution since late Pleistocene. It could be classified into seven evolution stages since 120 kaBP： 120-85 kaBP was a transition period from cold to warm; 85-76 kaBP was a period with warm and wet climate having swamp lakes developed in the lower reaches of the Weihe River, south coastal plain of Laizhou Bay; 76-50 kaBP was characterized by grassland vegetation and coarse sediments in terrestrial environment, which was the early stage of Dali Ice-Age; 50-24 kaBP was a period with alternate sea deposition in the south coastal plain of Laizhou Bay; 24-10 kaBP was the late stage of Dali Ice-Age with coldest period of Quaternary, the south coastal plain of Laizhou Bay was dry grassland and loess deposition environment; 10-4 kaBP was another warm and wet climate period, sea level was high and regressed at 4 kaBP; and has been the modern sedimentary environment since 4 kaBP. Among the three warm stages, including 85-76 kaBP, 50-24 kaBP and 10-4 kaBP, corresponded to late Yangkou, Guangrao and Kenli seawater transgression respectively. The duration of the latter one in south coastal plain of Laizhou Bay was longer than that in west coast of Bohai Sea and east coast of Laizhou Bay. The three periods of seawater transgression formed the foundation of salt-water intrusion in this area.

A New Mid Early Pleistocene Mammalian FaunaDiscovered in Choukoutien，China and Its Application in Biostratigraphy

This paper deals with a new Early Pleistocene micromammalian fauna found in Choukonden (Zhoukoudian) and its application in biostratigraphy.The new locality (east cave ), discovered in 1985,is located on the north slope of the Taipingshan Hill, about 2 km northeast of the Loc.1 in Choukoutien and is about 140-150m in altitude. At this locality,abundant fossil mammals are found in thick cave-fissure deposit. This fauna comprises 30mammalian taxa. Based on the comparison of the fauna, as Well as the sporo-pollen, climate events and paleomagnetic polarity section with those in other areas,we come to the conclusion that the sediments (Taipingshan Formation) in east cave were formed during the Period about from 1.67 Ma B. P. to 0.97 Ma B. P., and the fauna is about 1.20 Ma B. P. in ags.

Early-Middle Permian Reef Frameworks and Reef-building Models in the Eastern Kunlun Mountains

Reef frameworks and building models of the Early-Middle Permian in the eastern Kunlun Mountains have been verified through studies of reef-building communities, palaeoecology and carbonate facies. The eastern Kunlun reefs are built mainly by 6 reef-building communities, which include 11 major categories of frame-building organisms and 6 categories of reef-associated organisms. Eight types of reef-frames have been distinguished and eleven kinds of rocks identified to belong to 6 reef facies. Three sorts of reefs classified by previous researchers, namely mudmounds, knoll reefs and walled reefs, are well developed in the study area. Such reef-facies association and reef distribution show that there are 4 models of reef growth and development, i.e. the tidal-bank knoll-reef model, the plateau-margin wall-reef model, the composite wall-reef model and the deep-water mudmound model. The reefs are mainly constructed by calcareous sponge and calcareous algae, which are similar to all Permian reefs in other area

Sediment distribution and provenance since Late Pleistocene in Laizhou Bay,Bohai Sea,China

There are three transgression-regression events and evolutions of the sedimentary environment by sea level changes since the Pleistocene in the southern section of the Bohai Sea, China. It is obvious that a multi-source fluvial delta sedimentary system may be more dominant in a sedimentary environment. Based on previous research and survey or historical data, we carried out studies on the division of sedimentary units, sedimentary facies analysis and strata division and comparison, which aim to establish the sedimentary stratigraph of Laizhou Bay. We focus on the sedimentary procession of the Laizhou Bay since the early Late Pleistocene. It can be divided into two glacial periods and three interglacial periods, corresponding to two regression and three transgression events in Laizhou Bay since Late Pleistocene. In 124.6-72.0 ka BP, 60.0-24.4 ka BP and 10.2-4.0 ka BP, three times warm-wet periods occurred, respectively corresponding to the Cangzhou transgression, Xianxian transgression, and Huanghua transgression. In 72.0-60.0 ka BP and 24.4-10.2 ka BP, two dry and cold periods, it was the continental sedimentary environment, corresponding to Wurm early glacier and Wurm late glacier. The results show:(1) Sediments have the characteristics of phase and stage under the terrestrial input of the Yellow River and middle-small rivers in the southern section of the Bohai Sea.(2) PI moved towards coastal in Cangzhou transgression strata in early Late Pleistocene. PI moved northward from land in Xianxian transgression strata in the late Pleistocene. PI moved further north in the Huanghua transgression strata in Holocene.(3) During the regressive period, the land source input increased and the estuarine or lagoon sedimentation developed, which manifested as progradational superposition.(4) During the transgressive period, it mainly developed shallow coastal sediment and transitionally formed regressive deposition to the south in delta/tidal flat deposition.

Early-Middle Paleozoic Andes-type Continental Margin in the Chifeng Area, Inner Mongolia: Framework, Geochronology and Geochemistry and Implications for Tectonic Evolution of the Central Asian Orogenic Belt

Three tectonic units have been recognized in the Chifeng area, Inner Mongolia, from north to south, including the Qiganmiao accretionary prism, Jiefangyingzi arc belt and Sidaozhangpeng molasse basin, which formed an Andeantype active continent margin during the early to middle Paleozoic. The Qiganmiao accretionary prism is characterized by a mélange that consists of gabbro, two-mica quartz schist and basic volcanic rock blocks and heterogeneously deformed marble matrix. Two zircon U-Pb ages of 446.0±6.3 Ma and 1104±27 Ma have been acquired and been interpreted as the metamorphic and forming ages for the gabbro and two-mica quartz schist, respectively. The prism formed during the early to middle Paleozoic southward subduction of the Paleo Asian Ocean(PAO) and represents a suture between the North China craton(NCC) and Central Asian Orogenic Belt(CAOB). The Jiefangyingzi arc belt consists of pluton complex and volcanic rocks of the Xibiehe and Badangshan Formations, and Geochronology analysis indicates that the development of it can be divided into two stages. The first stage is represented by the Xibiehe Formation volcanic rocks, which belong to the subalkaline series, enriched LREE and LILE and depleted HFSE, with negative Eu anomalies, and plot in the volcanic arc field in discrimination diagrams. These characters indicate that the Xibiehe Formation results from to the continental arc magmatic activity related to the subduction of the PAO during 400–420 Ma. Magmatism of the second stage in 380–390 Ma consists of the Badangshan Formation volcanic rocks. Geochemistry analysis reveals that rhyolite, basaltic andesite and basalt of the Badangshan Formation were developed in continental margin arc setting. Moreover, the basaltic andesite and basalt display positive Sr anomalies, and the basalt have very low Nb/La values, suggesting that fluid is involved in magma evolution and the basalts were contaminated by continental crust. The sequence of Sidaozhangpeng molasse basin is characterized by proximity, coarseness and large thickness, similar to the proximity molasses basin. According to our field investigation, geochronological and geochemical data, combined with previous research in this area, a tectonic evolutionary model for Andes-type active continental margin of the CAOB has been proposed, including a development of the subduction-free PAO before 446 Ma, a subduction of the PAO and arc-related magmatism during 446–380 Ma, and formation of a molasse basin during 380–360 Ma.

Evolution of a Late Pleistocene palaeolake in Dali Nor area of southeastern Inner Mongolia Plateau,China

Lithological,geochronological,granulometric,and scanning electron microscope(SEM)analyses of eight lacustrine outcrops indicate the existence of a large palaeolake in Dali Nor area during 149-24.6 ka(MIS5-3)and a small one in upstream of the Xilamulun River during 12.96-11.69 ka.The large palaeolake recorded its highest water level above 1300 m during the MIS3 and covered the whole Dali Nor basin and upstream of the Xilamulun River within an area of about 3000 km^2.However,the small palaeolake with a highest water level above 1200 m,covered an area of about 600 km^2.Besides the reconstruction of palaeolake areas,this study also looked into the evolutionary process of the palaeolake during the Late Pleistocene.Our data provide insights on the timing of appearance of the large palaeolakes and a better understanding of the mechanism responsible for variations in the environment conditions of dry lands in middle latitudes.

Tectonic Uplift of the Yili Basin during the Last Stage of the Late Pleistocene: Evidence from ESR and OSL Dating of Sediments in the Huocheng Area, Xinjiang

The Quaternary sediments in the Yili Basin can serve as archives for studying the Cenozoic basin-mountain relationship. In this study, based on typical natural sections and boreholes, the surficial sediments of the Huocheng area were studied, and their sedimentary ages were obtained using the optically stimulated luminescence(OSL) and electron spin resonance(ESR) dating methods. These dates, combined with changes in the sedimentary facies, provided details of the neotectonic movement in the Yili Basin and adjacent areas. By dating sediments from five sections and three boreholes, we determined that the surficial sediments of the Huocheng area were mainly formed in the Late Pleistocene, with scattered instances of Holocene sediments. The surficial sediments mainly consisted of alluvial fan facies, fluvial facies, lacustrine facies, and desert facies. Based on the activity on the Hongshanzui fault and the northern margin fault of the Wusun Mountains, the Huocheng area was uplifted synchronously with the Tianshan Mountains during the last stage of the Late Pleistocene, causing the desert facies sediments to be superimposed on the former paleo-lake sediments.

ENVIRONMENTAL CHANGES SINCE LATE PLEISTOCENE IN ESTUARINE PLAIN OF JIULONG RIVER, FUJIAN PROVINCE

Based on the evidences of lithostratigraphy, palynology, micropaleontolopy and geochronology, paleoenvironments since the Late Pleistocene in the study area have been reconstructed. One of the most important inferences is that two marine transgressions have occurred, one in Wurm Sub-interglacial and the other Postglacial. The former had caused the study area to be in an estuary-bay envirment over the transgression maximum, with a sea level of no less than 10 m below present; foe latter reached its maximum over the Atlantic stage, with sedimentary environments of estuary-bay, hay or shallow sea, and the sea level arrived at the highest elevation in about 6 - 5 ka B.P. Furthermore, it is notable that, during the Late Wurm Glacial, the study area area had principally been in an estuary-bay environment, although the climate, like many other areas, turned cold and dry, It reflects a general trend of crustal subduction in Jiulong Estudrine Plain over this pened.

Uranium Series Chronology of the Late Pleistocene Basalt from the Longgang Volcanoes, Jilin Province

The Longgang volcanic cluster located in Jilin Province belongs to one of the active volcanic regions in northeast China, and has been active in modern times. In view of the multiple eruptions in history, it is very important to determine the age of each eruption for evaluating the volcanic hazards. Two alkaline basalt samples taken from Dayizishan and Diaoshuihu were analyzed with the U-series component dating after magnetic separation. The ages of the two samples are (71±9) ka and (106±13) ka B.P., respectively. These data indicate that there existed intensive eruption activities during the late Pleistocene.

Petrography, Geochemistry and Petrogensis of Pleistocene Basaltic Flow from Northwest Atarous Area, Central Jordan

Fifteen basaltic rock samples were collected from central Jordan at the Atarous volcanism basaltic flow area. The samples cover about 8 km2 from the Atarous Basalt flow (AB). The AB flow was introduced in the Miocene to Pleistocene periods. The samples analyze major and trace elements by using XRF. Petrography, Geochemistry and Petrogensis have investigation to carried out for the AB. The petrography analyses of the AB rocks show they are composed of plagioclase (labradorite and bytownite), pyroxene (augite), and olivine (forsterite);accessory minerals include apatite and secondary minerals magnetite, ilmenite, spinel and iddingsite. The AB is classified within alkaline to sub-alkaline and tholeiitic to Calc-Alkaline basalt. The Mg# range between 0.39 and 0.49 of basalt samples exhibits different degrees of fractionation with a low degree of melting < 15% as indicated from the varying concentration of incompatible trace elements Ba, Rb, Sr. Trace elements of primary magna show low variable abundances of compatible and incompatible elements, which reflecs a homogenous source. Geochemical parameters such as Mg# and high Ti contents indicate that the corresponding magmas are of primary origin. The tectonic setting of AB is explained by using discrimination diagrams, Ti-Zr-Sr and Nb-Zr-Y and Ti-Zr-Y, the AB plotted within the plate basalt, alkali basalt and Calk alkaline basalt field, respectively. The spider diagram shows the samples AB enrichment of the Ba, K, Nb and Ce, depletion of Nb and Y. The AB exhibited positive Nb, Ce and Ti anomalies, and negative anomalies of Ba, Sr, and P. It is attributed to the fractionation of feldspar for Ba and Sr and apatite for P depletion. The spider diagram showed a positive Nb peak, which conforms to the tertiary and to recent continental alkali basalt provinces and indicates that the AB is the product of lithosphere from upwelling asthenosphere mantle.

Geochemistry and environment evolution of Core E in the Laizhou Bay since last stage of Middle Pleistocene

Geochemistry analysis has been done on Core E (37 07' N, 118 55' E; depth: 82.1 m) taken from the Laizhou Bay in 1994. Nine kinds of invariable elements, 15 kinds of microelements and the content of lime carbonate are measured by means of ICP. The results indicate that most of the invariable elements and microelements in Core E show significant changes in the boundary stratotype, and the ratios between elements (Mn/Fe, Sr/Ba, Ti/Al) in particular. So they can be used as characteristic indicator to stratigraphic division of Quaternary. The changes of invariable elements are primarily controlled by the host minerals, and they mainly indicate the provenance as well as the sedimentation and depositional environment. Several elements, such as Fe, Al, Ca, Mg, Mn and Ti, are very sensitive to the provenance and environment. The distribution of microelements differs in four depositional periods: last stage of Middle Pleistocene, last interglacial period, last glacial period and Recent epoch, and especially in the 'cold period' and 'warm period'. The loops in the cycle curves of the most microelements correspond with the sand bed sediments, among which there are six sand units representing 'warm period' sediments, and one representing 'cold period' sediments. The carbonate is on the high side in the aeolian silt sediments formed in the glacial lowering of sea level in Core E, but on the low side in the transgressive sand beds formed in the interglacial period. The content variation of carbonate has a direct bearing on the grain size and the styles of sediments, and is a good indicator to the climate, environment and stratigraphic division.

DESERTIZATION OF THE CONTINENTAL SHELF OF CHINA IN THE LATER STAGE OF LATE PLEISTOCENE

In the later stage of Late Pleistocene, global climate entered into the climax period of Wurm when temperature decreased remarkably and glaciers developed. Information from the East China Sea also confirm that the sea level fell by at least 130 m at that time (Emery, 1968). The Bohai Sea and Yellow Sea at the climax period were totally exposed, while the East China Sea and South China Sea shelf regions were exposed partly. The exposed shelf area exceeded 1 million km2 and became a salty desert where land plants could not survive. Such were the conditions which led to the desertization of the shelf region.Eolation was the major exogenetic force not only on land but also on the shelf region in the ice age. At the climax period of Wiirm, the northern part of China developed thick layers of loess deposits. The shelf region at that time had similar climatic conditions and sediments. Because the shelf region was not protected by vegetation in the ice age, intensive wind storms remoulded the primarily

Late Pleistocene environmental information on the Diexi paleo-dammed lake of the upper Minjiang River in the eastern margin of the Tibetan Plateau, China

In 1999, Diexi paleo-dammed lake(2349 m a.s.l.) was discovered around Diexi town along the Minjiang River in Sichuan province. Diexi is located where the eastern edge of the Tibetan Plateau and the Sichuan Basin meet. The dammed lake was formed during the Last Glacial Maximum of the Late Pleistocene(~30,000 years ago) and began to empty about 15,000 years ago. The lacustrine sediments(up to 240 m thick) preserve abundant paleoenvironment information. In this paper, a mass of oxygen isotopes and 14 C dating from drilled cores are analyzed and discussed. The δ18 O curve on the paleo climate from this section is comparable with the coeval paleo climatic curves of ice cores and karsts in China and others. Furthermore, the physical model testing has confirmed that the disturbed zones in the core are caused by strong earthquakes occurred at least 10 times, which implies strong crustal deformation, as an important driving force, affecting climate change. This study provides a new window to observe East Asian monsoon formation, paleoenvironmental evolution and the global climate change.

Transgressive Events since the Late Pleistocene in the Yellow River Delta: Grain-size Distribution and Palynological Results

This study deals with the relationship between sea-level changes and paleoclimatic fluctuations based on the analysis of stratigraphy, grain sizes, palynology, and radiometric dating of the Yellow River delta since the Late Pleistocene. Evidence from the sedimentary record, grain sizes, and pollen provides a paleoenvironmental history of the Late Pleistocene from the boreholes of the delta. Based on a combination of grain-size analysis with lithological studies, marine deposit units contain the intervals of 13.85–16.9, 18.5–19.69, 27.9–34.8, 36.4–37.2, 48.4–51.6, and 54.1–55.9 m, and transitional facies units contain the intervals of 10.25–13.85, 16.9–18.5, 19.69–27.9, 34.8–36.4, 37.2–48.4, 51.6–54.1, and 55.9–60 m, compared with fluvial(terrestrial facies) deposit units(3.36–10.25 m). Based on pollen analysis and pollen assemblages, there were three warm-wet periods from 9.1–0.16 ka BP, 16.1–60 ka BP, and 90.1–94.6 ka BP From the top to the bottom of the borehole, the paleoclimate has an evident fluctuation: warm and moist(Holocene Optimum) —cool and dry(Younger Dryas Event)—mild semi cool—cool and dry—warm and moist. There were three warm-wet periods from 9.1–0.16 ka BP, 16.1–60 ka BP, and 90.1–94.6 ka BP, corresponding to the Holocene Optimum stage, MIS 3, and MIS 5, respectively. The warm period allowed monsoonal evergreen and broadleaved deciduous forests that corresponded to Holocene hypsithermal climatic conditions and the Late Pleistocene climatic Optimum. Three warm-wet periods occurred in marine deposit units from 9.1–0.16 ka BP, 60.1–16.1 ka BP, and 94.6–90.1 ka BP. These periods correspond to the Cangzhou transgression, Xianxian transgression, and Huanghua transgression, respectively. From 90.1–60.1 ka BP, 17.5–9.1 ka BP, and 0. 16 ka BP–1855 AD, three dry and cold phases are recognized. The phases indicate the fluvial(flood plain) sedimentary environment, corresponding to cooler and mild dry periods based on palynological results and grain-size distribution.

First Discovery of Dicerorhinus sumatrensis from Yanjinggou Provides Insights into the Pleistocene Rhinocerotidae of South China

The Rhinocerotidae is one of the most common and important families in the Pleistocene mammalian fauna of South China.Since the last century,most of the Pleistocene rhinocerotid fossils were prematurely assigned to Rhinoceros sinensis,which has resulted in confusion of taxonomy for decades,especially in South China.The Yanjinggou area in Chongqing Municipality of China,where the neotype of R.sinensis came from,has yielded abundant rhinocerotid fossils and is a key area to solve this problem.A recently discovered juvenile skull from a karstic fissure in this area can be referred to Dicerorhinus sumatrensis(Fischer,1814),which is the first confirmed non-Rhinoceros rhinocerotid from the area.This new finding indicates that non-Rhinoceros fossils might have been mixed in AMNH collection from Yanjinggou and thus the diagnosis of Rhinoceros sinensis needs reformation.On the other hand,Stephanorhinus?kirchbergensis is also detected in Granger’s collection based on our reobservation.The coexistence of Rhinoceros,Dicerorhinus and Stephanorhinus shows the higher diversity of Pleistocene rhinocerotids in South China.