Provenances,sedimentary environment of diatom ooze from core JL7KBC03,southern Challenger Deep,Mariana Trench,and its implication for carbon cycle and burial
The Hadal Trench plays a major role in driving the evolution of Earth's system.However,research on sedimentary processes in the Hadal Trench remains limited due to the challenges posed by its extreme depth.In this study,we present the sedimentary environment and provenances of the southern Mariana Trench,Challenger Deep,based on the systematic analysis of micropaleontology,sedimentology,and mineralogy.The results show that:① The sediment lithology is diatom ooze,dominated by large quantities of Ethmodiscus rex fragments.Silicic acid leakage from the Southern Ocean may have a significant impact on the blooming of E.rex,which enhanced silica content and reduced diatom dissolution,as well as supplementing silica in subsurface waters.The stimulation of Fe from eolian dust may also promote the blooming of E.rex.② Several dark laminations indicate frequent volcanic and hydrothermal activity.Provenance analysis,based on mineralogy and elemental geochemistry,suggests that abiogenic components were mainly contributed from the Kyushu-Palau Ridge and the Mariana Trench rather than from aeolian dust and hydrothermal materials sourced from the Pacific Ocean.③ The unique funnel-like topography and localized current dynamics of the Hadal Trench have been proven to contribute to the rapid precipitation and burial of organic matter.Plenty of organic matter was buried in the Hadal Trench seabed as diatom ooze,which plays an important role in balancing carbon storage between the lithosphere and the ocean.This process may represent a significant component of the global carbon cycle and burial.
Ethmodiscus rex oozesedimentary environmentprovenancescarbon cycle and burialMariana Trench
万方数据
维普
