Chuan-Chou (River) Shen
Chuan-Chou (River) Shen and his teams have been at the forefront of U-Th dating, as well as advanced elemental and isotopic analytical techniques. Over the past decades, their work has made significant contributions to geochronology, modern and paleo-climate reconstructions, paleoceanography, Asian monsoon evolution, and archaeology. His research primarily focuses on natural archives preserved in carbonate-based geological materials, including corals, speleothems, and foraminifera, and key study regions include the Asia-Pacific and Pan-Mediterranean.
River's domestic and international teams have achieved crucial developments, including ultra-high-precision coral dating with an accuracy of ±0.5 years or better, refined half-lives of 234U and 230Th, and new-generation U-Th dating techniques that extend the dating range to 700,000–800,000 years. His research has pioneered new geochemical proxies, including the direct measurement of carbonate-hosted rare earth elements, advanced H/O isotope analysis of nanoliter volumes of speleothem inclusion water, and innovative application of lithium isotopes to study silicate weathering in monsoonal regions.
Recent advances in U-Th chronology and geochemical proxies for reconstructing Asian monsoon variability from Speleothems
Since the early 2000s, speleothems have been widely recognized as valuable natural archive for reconstructing global paleoclimate evolutions, traditionally relying on carbon and oxygen isotopes as proxies for precipitation and vegetation changes, across various timescales over glacial-interglacial cycles. With the advantages of absolute chronology through U-Th dating and annual band counting, speleothem records have played a critical role in correlating and calibrating marine, terrestrial, and ice core records. Notably, Chinese stalagmite-inferred Asian monsoon evolution has become one of key benchmarks. Newly developed U-Th and U-Pb techniques can now extend speleothem records to over 640 ka (Cheng et al., 2016, Nature, v534, 640-646). During the past decades, new elemental, isotopic, and organic proxies have been proposed to reconstruct climate changes in Asia and beyond. For example, trace element ratios (e.g., Mg/Ca, Sr/Ca, Ba/Ca, and U/Ca), and possibly calcium isotopes, provide insights into hydrological changes, while sulfur peaks serve as markers of volcanic eruption events. Rare earth elements and lithium isotopes act as weathering proxies, and strontium isotopes trace dust storm activity. Lead levels and isotopes reflect anthropogenic pollution. Hydrogen and oxygen isotopes of fluid inclusion and carbonate triple oxygen isotopes offer clues about moisture sources. Past temperature reconstructions can be achieved using clumped isotopes, coeval carbonate and inclusion water oxygen isotopes, or TEX-86 techniques. These advancements in speleothem chronology and proxy development continue to enhance our understanding of hydroclimate and environmental changes in monsoonal and other regions worldwide.
