Geochemical provenance of sediments from the northern East China Sea document a gradual migration of the Asian Monsoon belt over the past 400,000 years
|Author(s)||Beny Francois1, 2, 3, Toucanne Samuel1, Skonieczny Charlotte4, 6, Bayon Germain1, Ziegler Martin5|
|Affiliation(s)||1 : IFREMER, Lab Geodynam & Enregistrement Sedimentaire, CS 10070, F-29280 Plouzane, France.
2 : Univ Lille, CNRS, Univ Littoral Cote DOpale, UMR 8187,LOG, F-59000 Lille, France.
3 : Vrije Univ Amsterdam, Dept Earth Sci, Fac Sci, De Boelelaan 1085, NL-1081 HV Amsterdam, Netherlands.
4 : Univ Paris Saclay, Univ Paris Sud, UMR CNRS 8148, Lab GEOsci Paris Sud GEOPS, F-91405 Orsay, France.
5 : Univ Utrecht, Heidelberglaan 2, NL-3584 CS Utrecht, Netherlands.
|Source||Quaternary Science Reviews (0277-3791) (Pergamon-elsevier Science Ltd), 2018-06 , Vol. 190 , P. 161-175|
|WOS© Times Cited||13|
|Keyword(s)||Monsoon, Eastern Asia, East China sea, Quaternary, Radiogenic isotopes, Neodymium, Rare earth elements|
The reconstruction of the long-term evolution of the East Asian Monsoon remains controversial. In this study, we aim to give a new outlook on this evolution by studying a 400 kyr long sediment record (U1429) from the northern East China Sea recovered during IODP Expedition 346. Neodymium isotopic ratios and rare earth element concentrations of different grain-size fractions reveal significant provenance changes of the sediments in the East China Sea between East Asian continental sources (mainly Yellow River) and sediment contributions from the Japanese Archipelago. These provenance changes are interpreted as the direct impact of sea level changes, due to the reorganization of East Asian river mouth locations and ocean circulation on the East China Sea shelf, and latitudinal shifts of the intertropical convergence zone (ITCZ) from the interior of Asia to the western North Pacific Ocean. Our data reveal the dominance of winter and summer monsoons during glacial and interglacial periods, respectively, except for glacial MIS 6d (∼150–180 ka) during which unexpected summer monsoon dominated conditions prevailed. Finally, our data suggests a possible strengthening of the interglacial summer monsoon rainfalls over the East Asian continent and Japan throughout the past 400 kyr, and between MIS 11 and MIS 5 in particular. This could result from a gradual northward migration of the ITCZ.