Provenance of sediments in the northern Manila Trench:An assessment from detrital zircon geochronology

Manila Trench is a critical region for revealing the tectonic evolution and source-to-sink process of the South China Sea,but the sediment provenance in the northern part of the trench remains unclear.In this study,we present a first detrital zircon U-Pb geochronology of sediments in the northern Manila Trench,in the vicinity of Northwestern Luzon Island,to identify the sediment provenance and understand the source-to-sink process in the marginal sea.The study shows that the sediments yielded multiple zircon age populations at ca.123,221,443,565,906,and 1871 Ma.A detailed detrital zircon age study indicates that the sediments were derived mainly from Taiwan Island,China,rather than the nearby Luzon Island.In comparison with the modern drainage systems surrounding northeastern South China Sea,this study further confirms that the sediments primarily originated from the Gaoping River(ca.45%),with subordinate contributions from the Lanyang River(ca.24%)and Min River(ca.19%).The study also elucidates two completely different sedimentary transport modes in the northern Manila Trench.The transportation of sediments from southwestern Taiwan Island is primarily related to the gravity-driven transport through the Gaoping submarine canyon.Furthermore,a quarter of detritus derived from eastern Taiwan Island might have been transported by the deep-water circulation of the Luzon Strait.This study highlights the provenance and transport pathway of sediments in the northern Manila Trench and provides a solution for understanding the source-to-sink process in the marginal sea.