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The Japan Sea is directly influenced by the Asian monsoon, a system that transports moisture and heat across southeast Asia during the boreal summer, and is a major driver of the Earth's ocean‐atmospheric circulation. Foraminiferal and facies analyses of a 460‐kyr record from Integrated Ocean Drilling Program Expedition 346 Site U1427 in the Japan Sea reveal a record of nutrient flux and oxygenation that varied due to sea level and East Asian monsoon intensity. The East Asian summer monsoon (EASM) was most intense during marine isotope stage (MIS) 5e, MIS 7e, MIS 9e, and MIS 11c when the Tsushima Warm Current flowed into an unrestricted well‐mixed normal salinity Japan Sea, whereas East Asian winter monsoon (EAWM) conditions dominated MIS 2, MIS 4, MIS 6, and MIS 8 when sea level minima restricted the Japan Sea resulting in low‐salinity and oxygen conditions in the absence of Tsushima flow. Reduced oxygen stratified, low‐salinity, and higher productivity oceanic conditions characterize Terminations TV, TIII, TII, and TI when East China Sea coastal waters breached the Tsushima Strait. Chinese loess, cave, and Lake Biwa (Japan) and U1427 proxy records suggest EASM intensification during low to high insolation transitions, whereas the strongest EAWM prevailed during lowest insolation periods or high to low insolation transitions. Ice sheet/CO2 forcing leads to the strongest EAWM events in glacials and enhanced EASM in interglacials. Mismatches between proxy patterns suggest that latitudinal and land/sea thermal contrasts played a role in East Asian monsoon variability, suggesting that a complex interplay between ice sheet dynamics, insolation, and thermal gradients controls monsoonal intensity.

©2018. American Geophysical Union. All Rights Reserved. The formation of the Pamir salient and the Tashkorgan-Yarkand River is highly debated with the ages ranging from pre-Cenozoic to late Miocene. One approach to resolve these issues is to draw support from the sedimentary record in the surrounding basins. A volcaniclastic sequence, which divides into Lower and Upper Members, was identified in the southwestern Tarim Basin. The Lower Member was transported by dilute streamflows, which likely flowed during or soon after eruptions, while the Upper Member was formed by a syneruptive volcanic debris flow. Chronological, petrologic, and geochemical data consistently indicate that the sequence was derived from the Central Pamir at ~11 Ma. The ~11 Ma emplacement of the volcaniclastic sequence provides unique constraints for the evolution of the Tashkorgan-Yarkand River and the Pamir salient. Provenance data indicate a multistage evolutionary history of the Tashkorgan-Yarkand River. The paleo-Tashkorgan River was initially formed in the piedmont of the Pamir marginal range before ~15 Ma. This river cut back into the Tashkorgan region at ~15 Ma, after which it has eroded the Central Pamir by ~11 Ma. The N-S trending upper reaches of the Tashkorgan River and the Yarkand River were established after ~11 Ma. The emplacement of the volcanic debris flow, together with regional deformation evidence, indicates limited strike-slip motion between Pamir and the Tarim at least since ~11 Ma, which refutes hundreds of kilometers offset between the Pamir and the Tarim after this time and supports an earlier indention of the Pamir salient.

The delta O-18 of seawater (delta O-18(w)), an indirect indicator of sea surface salinity (SSS), in the northern East China Sea (ECS) is reconstructed for the Holocene using paired analyses of Mg/Ca ratio and delta O-18 of planktic foraminiferal tests. According to modern observation, interannual variations in SSS during summer in the northern ECS are mainly controlled by the Changjiang (Yangtze River) discharge, which reflects summer rainfall in its drainage basin. Thus, changes in the summer SSS in the northern ECS are interpreted as reflecting variations in the East Asian summer monsoon (EASM) precipitation in the Changjiang Basin. This interpretation is confirmed by a strong relationship between the SSS in the northern ECS and the Changjiang discharge during the wet season (May-October) based on instrumental salinity records from 1951 to 2000. However, it is difficult to estimate absolute salinity values in the past with high accuracy, because the past salinity-delta O-18(w) regression slope, end member salinity, and delta O-18(w) values are not well understood. Here, we conduct delta O-18(w) mass-balance calculation to estimate the freshwater contribution to the surface water of the northern ECS during the last 7 kyr by assuming a simple mixing between two end members - the seawater and the Changjiang freshwater. The result indicates that there has been no gradual decreasing secular trend in the Changjiang freshwater flux from the middle Holocene to the present day, suggesting that summer insolation in the Northern Hemisphere does not regulate the EASM precipitation in the Changjiang Basin. Instead, internal feedback appears to have been more important during the Holocene. The absence of a decreasing trend in regional summer precipitation over the Changjiang Basin since the middle Holocene is contradictory to Chinese speleothems' delta O-18 records, suggesting that it is not possible to explain orbital changes in Chinese speleothems' delta O-18 during the Holoc

As the world’s second largest sand sea and one of the most important dust sources to the global aerosol system, the formation of the Taklimakan Desert marks a major environmental event in central Asia during the Cenozoic. Determining when and how the desert formed holds the key to better understanding the tectonic–climatic linkage in this critical region. However, the age of the Taklimakan remains controversial, with the dominant view being from ~3.4 Ma to ~7 Ma based on magnetostratigraphy of sedimentary sequences within and along the margins of the desert. In this study, we applied radioisotopic methods to precisely date a volcanic tuff preserved in the stratigraphy. We constrained the initial desertification to be late Oligocene to early Miocene, between ~26.7 Ma and 22.6 Ma. We suggest that the Taklimakan Desert was formed as a response to a combination of widespread regional aridification and increased erosion in the surrounding mountain fronts, both of which are closely linked to the tectonic uplift of the Tibetan–Pamir Plateau and Tian Shan, which had reached a climatically sensitive threshold at this time.

The development of fluvial systems in East Asia is closely linked to the evolving topography following India–Eurasia collision. Despite this, the age of the Yangtze River system has been strongly debated, with estimates ranging from 40 to 45 Ma, to a more recent initiation around 2 Ma. Here, we present 40Ar/39Ar ages from basalts interbedded with fluvial sediments from the lower reaches of the Yangtze together with detrital zircon U–Pb ages from sand grains within these sediments. We show that a river containing sediments indistinguishable from the modern river was established before ~23 Ma. We argue that the connection through the Three Gorges must postdate 36.5 Ma because of evaporite and lacustrine sedimentation in the Jianghan Basin before that time. We propose that the present Yangtze River system formed in response to regional extension throughout eastern China, synchronous with the start of strike–slip tectonism and surface uplift in eastern Tibet and fed by strengthened rains caused by the newly intensified summer monsoon.