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Chronological sequences of Quaternary terrestrial mammalian faunas can provide important information about the evolutionary history of mammals, regional biostratigraphy and paleoenvironmental changes. Here we report the results of studies of a thick, nearly-continuous sedimentary sequence from Jinyuan Cave, in Liaoning Province, northeast China; the sequences contains four mammalian faunas ranging in age from the Late Pliocene to the late Middle Pleistocene. Detailed paleomagnetic and U-series age determinations date the upper unit of the sedimentary sequence to ~2.2–0.3 Ma. The results suggest that cave development and infilling were closely associated with the tectonic evolution of the Bohai Basin, including the subsidence of the basin and the uplift of the surrounding mountains, such as Luotuo Hill. Together with the large mammalian faunas from both south and north China, we suggest that these mammalian faunas were smaller in size and lower in species diversity during the Middle Pleistocene Transition (MPT) (1.2–0.7 Ma) than in the earlier and later Pleistocene. This indicates that major climatic variations during the MPT in north China may have reduced their taxonomic abundance and diversity. The extremely warm and wet interglacial climates that followed the MPT in monsoonal East Asia provided an ecological niche for the evolution and migration of these mammalian faunas, resulting in an increase in the numbers and diversity of mammals in East Asia. [ABSTRACT FROM AUTHOR]

The 4.2 ka climate event, which marks the start of the late Holocene (Meghalayan), is linked to disruption to human cultures across a wide belt from the eastern Mediterranean to the Yangtze River Valley. Here we present a high-resolution stalagmite δ13C record for the middle Yangtze Valley from 4.4 to 3.0 ka BP, and identify two humid pulses and two dry episodes associated with the 4.2 ka event. Similar hydroclimate fluctuations associated with the 4.2 ka event also occur in the Chinese Loess Plateau and Central Plains of China, and may be at least partly responsible for the decline of the Neolithic culture in these regions. Although the 4.2 ka event marks the internationally recognised boundary between the middle and late Holocene, our stalagmite-based evidence shows that regime shift in hydrological variability occurred at ∼3.5 ka BP in the middle Yangtze Valley. Regime shift correlates with inflection points of temperature in the extratropical Northern Hemisphere and tropical El Niño Southern Oscillation (ENSO) systems, indicating teleconnections between local and global climate change at this time. Following regime shift, precipitation fluctuated with a larger amplitude. Two dry events and one humid rebound event correspond to the early, late, and middle phases of the Shang Dynasty, respectively. In summary, we propose that frequent climatic alternations and their increased amplitudes impacted late Holocene cultural evolution in China. • Precipitation pulses and dry episodes characterized the 4.2 ka event. • A hydrological regime shift occurred in the middle Yangtze Valley at ∼3.5 ka BP. • Climatic alternations influenced cultural evolution during the late Holocene. [ABSTRACT FROM AUTHOR]

A multi-proxy (δ18O, δ13C and trace elements) analysis of an absolutely-dated stalagmite in northern China is conducted to reconstruct the East Asian summer monsoon (EASM) intensity and local hydroclimate conditions during the period of 53.8–47.4 ka (BP, before 1950 CE). Our δ18O and δ13C records, with 24-yr resolution, clearly register the Dansgaard-Oeschger (DO) events 14 and 13. A clear double-peak structure for DO13, as previously detected in the NGRIP ice core, is identified in our δ18O and δ13C records, for the first time. This strong correspondence at the finer time-scale indicates a sensitive and rapid response of the EASM system to the North Atlantic climate changes through air-sea coupling. Our δ18O record shows that the EASM intensity deceased abruptly during latter stage of DO14 (51.1–50.3 ka). This abrupt change is different from other stalagmite δ18O records from central and southern China. On the other hand, both the δ13C and trace element records, representing local hydroclimatic changes, match well with the δ18O record, reflecting an integrated EASM system, on the timescale of the DO cycles. The covariance suggests that the hydrological variation in northern China could be modulated by the movement of the large-scale EASM circulation. Further comparison displays an anti-correlated relationship between the millennial precipitation changes in northern and southeastern China during the period of 51.5–47.4 ka. This anti-correlation is analogous to the "North-South" dipole mode in observed present-day precipitation. Overall, this study advances our understanding of the spatial and temporal evolution of the EASM precipitation on the millennial timescale. • Variations in ASM and local hydrology during MIS 3 were reconstructed in northern China by multi-proxy stalagmite records. • The "double peak" structure features of DO13 event in NGRIP was firstly identified in monsoonal China. • There is a strong coupling of the local hydrological conditions and the large-scale atmospheric circulation. • The dipole precipitation mode between northern and southern China was observed at 51.5–47.4 ka BP. [ABSTRACT FROM AUTHOR]

Asian summer monsoon (ASM) and regional rainfall responses to external and internal forcings remain actively debated, especially at significant climate transitions. Here we present decadally-resolved stalagmite stable isotope (δ18O and δ13C) and trace element records from central China to reconstruct Asian hydroclimate variability across the Marine Isotope Stage (MIS) 7/6 transition. The results demonstrate that the maximum level of effective precipitation (or precipitation/evaporation, P/E), derived from δ13C and element records, is practically similar between MIS 7.0 and early MIS 6.5, punctuated by a series of centennial-scale moisture-deficit events, in contrast to precessional-scale ASM changes (i.e., δ18O). At millennial scale, the ASM decline is positively correlated to P/E changes, with an exponential relationship between them. It reveals that Earth's boundary conditions could differently modulate ASM and P/E changes at orbital scale, while internal forcings can generate synchronous responses. Moreover, the ASM intensity and P/E conditions exhibit enhanced instability into MIS 6, about 1.5 times in amplitude of MIS 7. These millennial-scale hydroclimate variations are in line with a rise of Northern Hemisphere summer insolation, an El Niño/La Niña transition, the increased seasonality and high-frequency tropical climate variability. Hence, low-latitude hydrological conditions could be susceptible to subtle perturbations in the climate system, providing a precondition for the arrival of MIS 6. • Decadally-resolved stalagmite isotopic and element records across the MIS 7/6 transition. • Contrasting responses of ASM intensity and effective precipitation in central China. • Enhanced Asian hydroclimate instability during early MIS 6. • A role of low-latitude hydrological processes on centennial-scale Asian hydroclimate variability. [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]

Knowing the behavior of the Asian summer monsoon (ASM) and its global correlation help understand roles of the ASM in global climate change. Here we synthesize a stalagmite δ18O record, based on a new record and an available nearby record, both covering the nearly entire Holocene. The synthesized δ18O record correlates with meridional migration of the Intertropical Convergence Zone (ITCZ), and with change in inter-subtropical insolation contrast throughout the Holocene. However, its correlation with the Atlantic meridional overturning circulation (AMOC) broken down during the period of the strongest ASM, when the AMOC weakened. This scenario points to a persistent influence of the ITCZ and subtropical insolation contrast on the change in ASM throughout the Holocene. Our record also correlates with a change in atmospheric CO 2 concentration on the multi-millennial scale. These correlations of our cave record with variations in the ITCZ, subtropical insolation contrast, and CO 2 level indicate that changes in low-latitude climates, including the ASM, were involved in the evolution of the Holocene CO 2 concentration. These changes in the low-latitude climates were likely connected with variation in the Holocene southern westerly wind, which modulated upwelling of carbon-enriched deep ocean water around Antarctica. On the multi-centennial scale, seven weak ASM events are identified, with the magnitudes of the Younger Dryas and the events at 9.8 ka and 8.2 ka event broadly three and two times larger than the other ones. These events have a quasi-period of approximately 1.463 ka. This period in the monsoon regime probably arose from solar activity, but involving the feedback of ENSO. In summary, our study provides insights into the connection of the Holocene ASM with tropical climate, and into the involvement of the ASM in the change of the Holocene CO 2 concentration. • A new Holocene stalagmite record is provided from southwestern China. • The Asian summer monsoon was probably involved in the evolution of the Holocene atmospheric CO 2 concentration. • Weak monsoon events corresponded to states of more El Niño events. [ABSTRACT FROM AUTHOR]

• A pronounced shift in Asian monsoon is identified during the last interglacial. • There were two monsoon phases in the latter last interglacial. • Rapid demise of the last interglacial Asian monsoon was due to the gradual decrease of summer insolation. The last interglacial contains information about how climate behaves during a warm period comparable to the current interval. However, there is no consensus on the key signatures and force of the last interglacial climate changes at present. Here we present a high-resolution stalagmite oxygen isotope record from central China, which spans from 123.3 to 116.8 ka. The stalagmite δ18O time-series bears a resemblance to changes in Northern Hemisphere summer insolation before the demise of the last interglacial, like the condition during the Holocene. Superimposed on the long-term δ18O record is a pronounced shift to more positive values at around 121.6 ka, indicating a switch of the Asian monsoon mean state into a weaker condition. This monsoon shift correlates with a decrease in the mean state of the South American Summer Monsoon, and a well-known abrupt mid-Eemian cooling event at high latitudes. These correlations indicate broad-scale features of the climate shift over the warm last interglacial. Another positive δ18O shift of up to 3.5‰ occurred at around 120 ka, representing the demise of the last interglacial Asian monsoon. By comparing the stalagmite δ18O records against changes in ice volume and summer insolation during the last interglacial and recent Holocene, respectively, we conclude that the decreasing Northern Hemisphere summer insolation dominated the rapid demise of the last interglacial in the Asian monsoon region. [ABSTRACT FROM AUTHOR]

Marine Oxygen Isotope Stage 12 (MIS 12), the last glacial period before the Mid-Brunhes event (MBE), is considered the coldest glacial period during the past several glacial/interglacial cycles and is important because it can help better understand the cyclicity and mechanism of the millennial-scale variability of a glacial period. However, owing to the lack of precisely dated and high-temporal-resolution records, the millennial-scale variability during this period remains unclear. A 230Th/U dated stalagmite from Luoshui Cave, Hubei Province, Central China, was analyzed for stable oxygen isotopes (δ18O). An ∼120-yr-resolution δ18O profile is presented to clarify the Asian summer monsoon (ASM) history between 464 and 420.6 kyr BP (Before present, where present = 1950 CE), which corresponds to the interval from the MIS 12 to the early part of the MIS 11. The MIS 12 monsoon generally followed the insolation differences on June 21 between 30°N and 30°S and was interrupted by ten Chinese interstadial events (CISs). At least nine prominent weak monsoon intervals (WMIs) were identified during MIS 12 and displayed a strong coupling with the northern high-latitude climate and Antarctic temperature through the bipolar seesaw model, suggesting a substantial relationship with the bipolar region. This indicates that millennial-scale variability in the ASM region is an inherent feature of the MBE and has a global teleconnection. Additionally, in contrast to the EPICA DOME C3 (EDC 3) timescale, the new absolutely dated speleothem record confirms the Antarctic Ice Core Chronology 2012 (AICC 2012) at MIS 12, a period with a large difference between the two ice record geochronologies over the past 800 kyr. • A high resolution and precision dating stalagmite record was presented to clarify the ASM history of MIS 12 in China. • The new record over the MIS 12 follows orbitally induced insolation variations and is interrupted by thirteen CISs and nine WMIs on the millennial-scale. • The CISs are consistent to the variation of Mid-high North Atlantic environment. • The WMIs over MIS12 presented anti-phased relationship with Antarctic temperature. • This research confirms that the millennial scale climate variation before the MBE is a continuous feature. [ABSTRACT FROM AUTHOR]

Multi-proxy analysis of abrupt climate change during Ice Age Termination III (T-III) is necessary to understand Asian summer monsoon (ASM) characteristics and mechanisms. We present 230Th dates and δ 18O, δ 13C, with equilibrium diameter, carbonate deposition amount and lithological characteristics from an annually laminated stalagmite (No. YXB) in Yongxing Cave, central China. Our multi-proxy records span 243.90 to 239.20 ka before present, falling within T-III/Marine Isotope Stage 7e. The changes in δ 18O, equilibrium diameter, carbonate deposition amount, and lithological characteristics suggest a weak ASM interval during T III. By comparing these results with records from Ice Age Termination I (T-I), we find that the weakened ASM event during T-III is similar to the Younger Dryas (YD) event in terms of duration and structure. This result suggests that the YD-like event could be an inherent feature of glacial-interglacial climate cycles in the middle and late Pleistocene. The YXB δ 13C sequence, without YD-like events, is broadly similar to the δ 18O record on orbital timescale, indicating that variations in local vegetation could be driven by rising CO 2 during ice age terminations. • Stalagmite records based on layer counting chronology from Southern China. • Stalagmite δ 18O, lithological characteristics indicate a weak Asian summer monsoon interval during Termination III. • Duration and structure of weak monsoon interval during Termination III is similar to Younger Dryas. • δ 13C indicates no YD-III but driven by greenhouse gases during ice age terminations. [ABSTRACT FROM AUTHOR]

The Asian hydroclimate variability during the early and middle Marine Isotope Stage (MIS) 3 was reconstructed from a high-resolution stalagmite δ18O record from Qixing Cave in southern China, which exhibited an extraordinarily strong precessional cycle. When compared with other cave records (mostly) from East Asia, covering a latitudinal transect from 23° to 38°N, it can be found that the magnitude of precessional-scale stalagmite δ18O variations decreases when the latitude increases, approximately from 3‰ to 1‰. In contrast, the amplitude of Heinrich stadials (HSs) in these stalagmite δ18O records enhances with increasing latitudes, from 1‰ to 2‰, reflecting an alleviated effect of high-latitude climate changes on the low-latitude hydroclimate, or a relative contribution from Westerlies-borne and near-sourced 18O-enriched moisture at northern China. In southern China, orbital-scale changes in stalagmite δ18O closely match variations of the atmospheric CH 4 concentration and δ18O of the atmospheric O 2 , suggesting a coherent response of low-latitude ecological and hydrological processes. In addition, a weaker precessional cycle in northern China is possibly related to the relative supply of near-sourced moisture source, where the Westerly wind can exert a substantial role. Therefore, precessional to millennial-scale changes in East Asian stalagmite δ18O records could be further modulated by local processes, rendering them a spatially contrasting trait. A pervasive imprint of muted precessional rainfall changes in loess records from northern China suggests a regionally distinct rhythm of moisture availability, in agreement with the stalagmite records from higher latitudes. • An increase of HS amplitude but weakening of the precessional cycle with increasing latitudes. • The role of low-latitude processes on alleviating the HS amplitude in southern China. • A dividing role of the latitudinal band ∼30°N on controlling the moisture supply in East Asia. • The barrier effect of Westerly jet and different moisture sources modulate precessional hydroclimate changes in northern China. [ABSTRACT FROM AUTHOR]