Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.
Corresponding millennial‐scale climate changes have been reported from the North Atlantic region and from east Asia for the last glacial period on independent timescales only. To assess their degree of synchrony we suggest interpreting Greenland ice core dust parameters as proxies for the east Asian monsoon systems. This allows comparing North Atlantic and east Asian climate on the same timescale in high resolution ice core data without relative dating uncertainties. We find that during Dansgaard‐Oeschger events North Atlantic region temperature and east Asian storminess were tightly coupled and changed synchronously within 5–10 years with no systematic lead or lag, thus providing instantaneous climatic feedback. The tight link between North Atlantic and east Asian glacial climate could have amplified changes in the northern polar cell to larger scales. We further find evidence for an early onset of a Younger Dryas‐like event in continental Asia, which gives evidence for heterogeneous climate change within east Asia during the last deglaciation.
[1] Dune fields in parts of northern China contain important stratigraphic records of late Quaternary change in the East Asian monsoon. In this study, 33 new optically stimulated luminescence (OSL) ages and other measurements from aeolian sediment sections are used to reconstruct the timing of wet-dry climate variation in the Mu Us and Otindag dune fields of north China. The results indicate dune activity and dry climate in the last few hundred years, 14 ka to about 7 -8 ka, and 50 ka to 60 ka. The dunes were mainly stable, implying a wetter climate, between about 7 -8 ka and 2.4 ka. These results imply a lag of several thousand years between peak summer insolation at 10-11 ka and high summer monsoon rainfall after 7 -8 ka. In the investigated regions, the monsoon climate may not respond directly to orbital forcing over millennial time scales. Land surface feedbacks may account for lagged dune field response.
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