A high-resolution clay mineralogical record in the northern South China Sea since the Last Glacial Maximum,and its time series provenance analysis  

作　　者：LIU ZhiFei LI XiaJing COLIN Christophe GE HuangMin 

机构地区：[1]State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China [2]Laboratoire IDES, UMR 8148 CNRS, Universit~ de Paris XI, Orsay 91405, France

出　　处：《Chinese Science Bulletin》2010年第35期4058-4068,共11页

基　　金：supported by the National Natural Science Foundation of China (40925008,40876024 and 40776027);the National Basic Research Program of China (2007CB815906);the Shanghai Shuguang Program (07SG23);the Shanghai Subject Chief Scientist Program (10XD1406300)

摘　　要：High-resolution clay mineralogical analysis of Core MD05-2904 in the northern South China Sea(SCS) covering the period since the Last Glacial Maximum shows that illite(29%-48%),smectite(14%-45%),chlorite(17%-28%),and minor kaolinite(6%-14%) comprise the clay mineral assemblage,and that time series variation does not present glacial-interglacial cyclicity.Provenance analysis indicates three end-member sources:almost all smectite derives from Luzon,all kaolinite is sourced from the Pearl River,and illite and chlorite originate from both the Pearl River and Taiwan.By comparing clay mineral compositions in surface sediments from the three major source areas and of the SCS,we reconstructed a time series of clay mineral contribution from the major provenances to the northern slope of the SCS using the linear separation method for illite crystallinity.There were three stages of provenance change.(1) During 24.1-17.5 ka BP,contributions from Taiwan and Luzon were similar(30%-40%),while that from the Pearl River was only 25%.(2) During 17.5-14.0 ka BP,the contribution from Luzon decreased rapidly to 20%-25%,while that from Taiwan increased to 35% from an average of 25% at 18 ka BP,and that from the Pearl River increased largely to 40%.(3) During the Holocene,differences in contributions from the three major provenances increased:the contribution from Luzon increased slightly and then remained at 27%-35%,that from Taiwan increased rapidly and then remained at 55%-60%,and that from the Pearl River decreased to 15%.The change in clay mineral contributions from different provenances is influenced mainly by clay mineral production,monsoon rainfall denudation,oceanic current transport,and sea-level change.High-resolution clay mineralogical analysis of Core MD05-2904 in the northern South China Sea （SCS） covering the period since the Last Glacial Maximum shows that illite （29%-48%）, smectite （14%-45%）, chlorite （17%-28%）, and minor kaolinite （6%-14%） comprise the clay mineral assemblage, and that time series variation does not present glacial-interglacial cyclicity. Provenance analysis indicates three end-member sources： almost all smectite derives from Luzon, all kaolinite is sourced from the Pearl River, and illite and chlorite originate from both the Pearl River and Taiwan. By comparing clay mineral compositions in surface sediments from the three major source areas and of the SCS, we reconstructed a time series of clay mineral contribution from the major provenances to the northern slope of the SCS using the linear separation method for illite crystallinity. There were three stages of provenance change. （1） During 24.1-17.5 ka BP, contributions from Taiwan and Luzon were similar （30%-40%）, while that from the Pearl River was only 25%. （2） During 17.5-14.0 ka BP, the contribution from Luzon decreased rapidly to 20%-25%, while that from Taiwan increased to 35% from an average of 25% at 18 ka BP, and that from the Pearl River increased largely to 40%. （3） During the Holocene, differences in contributions from the three major provenances increased： the contribu- tion from Luzon increased slightly and then remained at 27%-35%, that from Taiwan increased rapidly and then remained at 55%-60%, and that from the Pearl River decreased to 15%. The change in clay mineral contributions from different provenances is influenced mainly by clay mineral production, monsoon rainfall denudation, oceanic current transport, and sea-level change.

关 键 词：粘土矿物 南海北部 时间序列 高分辨率 中国海 末次盛冰期 Sea 珠江源 

分 类 号：P578.94[天文地球—矿物学] O211.61[天文地球—地质学]