A high-resolution clay mineralogical record in the northern South China Sea since the Last Glacial Maximum, and its time series provenance analysis
A high-resolution clay mineralogical record in the northern South China Sea since the Last Glacial Maximum, and its time series provenance analysis
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DOI：
10.1007/s11434-010-4149-5
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发表时间：
2010-10
影响因子：
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通讯作者：
Zhifei Liu;Xiajing Li;C. Colin;Huangmin Ge
中科院分区：
文献类型：
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作者：
Zhifei Liu;Xiajing Li;C. Colin;Huangmin Ge
对南海北方MD 05 -2904孔末次盛冰期以来的高分辨率粘土矿物学分析表明，粘土矿物组合主要由伊利石（29%-48%）、蒙皂石（14%-45%）、蒙脱石（17%-28%）和少量高岭石（6%-14%）组成。时间序列变化不存在冰期-间冰期旋回性。物源分析表明，三个端员来源：几乎所有的蒙皂石来源于吕宋岛，所有的高岭石来源于珠江，和伊利石和伊利石来源于珠江和台湾。通过对南海3个主要物源区和南海表层沉积物中粘土矿物组成的比较，采用伊利石结晶度线性分离方法，重建了南海北方斜坡主要物源区粘土矿物贡献的时间序列。种源变化经历了三个阶段。(1)在24.1- 17.5kaBP期间，来自台湾和吕宋岛的贡献相似（30%-40%），而来自珠江的贡献仅为25%。(2)17.5- 14.0kaBP，吕宋岛的贡献率迅速下降到20%~ 25%，而台湾的贡献率从18 kaBP的平均25%上升到35%，珠江的贡献率大幅上升到40%。(3)全新世期间，三个主要种源的贡献率差异增大：吕宋岛种源的贡献率略有增加，之后维持在27%~ 35%，台湾种源的贡献率迅速增加，之后维持在55%~ 60%，珠江种源的贡献率下降到15%。不同物源粘土矿物贡献的变化主要受粘土矿物生产、季风降雨剥蚀、洋流输送和海平面变化的影响。
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.