海洋地质与第四纪地质2024，Vol.44Issue(2)：146-156,11.DOI:10.16562/j.cnki.0256-1492.2023121201
90 kaBP以来阿拉伯海中部海域沉积物来源及沉积过程
Sediment sources and sedimentary processes in the middle Arabian Sea since 90 kaBP
摘要
Abstract
Based on the geochemical characteristics and clay mineral composition of Core AS06-13 in the middle Arabian Sea,we combined the age of foraminifera shell AMS14C and the dating framework of oxygen isotope data,the provenance and sedimentary evolution of the middle Arabian Sea were studied.Results show that Core AS06-13 was deposited since 90 kaBP,with average depositional rate of 2.34 cm/ka.The Rare Earth Element(REE)content ranged from 64.38 to 194.33 μg/g,with average of 113.66 μg/g.The δEu,on average of 0.71,dispalyed significant negative anomaly.The clay minerals were mainly composed of illite(56%in average),palychite(18%in average),chlorite(15%in average),kaolinite(8%in average),and montmorillonite(2%in average).The chondrites normalized patterns of REEs had shown a right-leaning pattern of the enrichment in light REEs and deficit in heavy REEs,suggesting that sediments in the study area were mainly terrigenous detritals.According to the δEuUCC-(La/Yb)UCC discriminant diagram,the provenance changes in the middle Arabian Sea can be divide into three stages since 90 kaBP.The stage S1(90～73 kaBP)were mainly sourced from the Indus River and the Arabian Peninsula dust.The stage S2(73～11 kaBP)exhibited similarities to the stage S1,albeit with a discernible tendency towards being influenced by the Peninsular Gneissic rock region.The stage S3(11～0 kaBP)had a mixed sources including the Indus River,Arabian Peninsula dust,gneiss region,and the Deccan Plateau.The content of palygorskite and the ratio of kaolinite/illite indicated that the terrigenous input and sedimentary evolution in the central Arabian Sea were mainly controlled by monsoon and sea level changes since 90 kaBP.The weakening of the southwest monsoon and decrease in sea level led to an increase in fluvial sediment inputs from Indus River and Deccan Plateau to the study area.The enhanced winter winds and the relative strengthened northwesterly winds resulted in an elevated dust input originating from the Arabian Peninsula.The Holocene sea-level rise led to a rapid decline in fluvial sediments supply to the Arabian Sea.关键词
沉积物/稀土元素/黏土矿物/物源/沉积过程/阿拉伯海Key words
sediment/rare earth elements/clay minerals/provenance/sedimentary processes/Arabian Sea分类
海洋科学引用本文复制引用
陶菁,孟元库,石学法,刘升发,艾丽娜,曹鹏,黄牧,张辉,吴凯凯,齐文菁,方桐冰..90 kaBP以来阿拉伯海中部海域沉积物来源及沉积过程[J].海洋地质与第四纪地质,2024,44(2):146-156,11.基金项目
全球变化与海气相互作用(二期)专项"西印度洋WIND-CJ06区块海洋底质与底栖生物调查"(GASI-01-WIND-CJ06) （二期）
