海洋地质前沿2026，Vol.42Issue(2)：77-89,13.DOI:10.16028/j.1009-2722.2024.285
近1 Ma帕里西维拉海盆沉积物的粒度分布以及亚洲风尘沉积对东亚冬季风的响应
Grain size distribution of the Parece Vela Basin sediments and the response of Asian dust deposition to the East Asian winter monsoon during the past 1 million years
摘要
Abstract
Asian dust within the Parece Vela Basin(PVB)mainly originates from the arid regions of Asia,and dust particle size and dust flux(MAR mass accumulation rate)play a very important role in indicating the strength of the East Asian winter monsoon and the degree of aridification of the source region.In this study,we quantitat-ively separated the detrital fractions of samples within the PVB by the Weibull function fitting method,analyzed the sources of different fractions in combination with the Sr and Nd isotopic signatures of the sediments,and re-constructed the dust MAR within the PVB during the past 1 Ma.Results indicate that the fine-grained fraction of core CP-19 varies in grain size from 0.1 to 12.6 μm,averaging around 1.9 μm in modal grain size and about 50.0%in content.It is inferred that this fraction is Asian dust,mainly originating from the deserts of eastern Asia and the Chinese loess plateau region,with a dust MAR ranging from 22.6 to 91.5 mg·cm-2·ka-1(average 62.8 mg·cm-2·ka-1).The coarse-grained fraction of core CP-19 varies in grain size from 1.3 to 58.5 μm,averaging around 13.2 μm in modal grain size and about 44.2%in content.This fraction is inferred to be proximal volcanic material,mainly sourced from the nearby west Mariana ridge,with a volcanic material MAR ranging from 27.3 to 167.9 mg·cm-2·ka-1(average 60.5 mg·cm-2·ka-1).The increase in dust MAR within the PVB during the near 1 Ma period reflects the overall persistent arid climatic characteristics of the East Asian dust source region.During the period from 1 to 0.6 Ma,the dust MAR trends within the PVB and between the Pacific Ocean show that the differ-ences are influenced by the enhanced East Asian winter monsoon.From 0.6 Ma to the present,the climate change cycle is clearly defined,and the dust MAR trends in the PVB and the Pacific Ocean are synchronized,which to-gether reflect the climatic features of enhanced winter monsoon and intensified aridification in East Asia during the ice age phase as well as the weakening of the winter monsoon intensity and aridification in the last ice age.关键词
帕里西维拉海盆/粒度分布/亚洲风尘/东亚冬季风Key words
Parece Vela Basin/grain size distribution/Asian dust/East Asian winter monsoon分类
海洋科学引用本文复制引用
孙永强,闫义,赵奇,刘兰..近1 Ma帕里西维拉海盆沉积物的粒度分布以及亚洲风尘沉积对东亚冬季风的响应[J].海洋地质前沿,2026,42(2):77-89,13.基金项目
国家重点研发计划"晚新生代亚洲大陆风化过程、沉积记录及碳汇效应"(2022YFF0800503) （2022YFF0800503）
