Mineralogy and stable isotopic composition of authigenic carbonates in bottom sediments in the offshore area of southwest Taiwan, South China Sea:Evidence for gas hydrates occurrence.
Mineralogy and stable isotopic composition of authigenic carbonates in bottom sediments in the offshore area of southwest Taiwan, South China Sea:Evidence for gas hydrates occurrence.
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发表时间：
2005
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通讯作者：
Lü Hong-Feng;L. Jian;C. Fang;Liao Zhi-liang;Sun Xiao-ming;S. Xin
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作者：
Lü Hong-Feng;L. Jian;C. Fang;Liao Zhi-liang;Sun Xiao-ming;S. Xin
台湾西南海域南海是天然气水合物最佳勘探区。该地区的自生碳酸盐以结壳和烟囱的形式存在。 X射线研究表明，碳酸盐矿物有文石、高镁方解石、少量白云石、铁白云石和菱铁矿。霰石是针状的、细长的并且填充碳酸盐的空隙。高镁方解石呈粒状。碳酸盐岩的δ~(13)C值范围为-56.878‰PDB～-32.829‰PDB，大部分小于-40‰PDB，表明存在与微生物甲烷相关的碳库。碳酸盐岩的δ~(18)O值范围为2.1875‰PDB至5.045‰PDB，O同位素比值较大，表明水资源富含~(18)O。矿物学和氧、碳稳定同位素组成的研究提供了台湾西南近海碳酸盐可能是由天然气水合物解离产生的冷泉沉淀出来的线索。[KG]]
The offshore area of southwest Taiwan, South China Sea, is the best gas-hydrate prospect area. Authigenic carbonates in the area occur in the form of crusts and chimneys. X-ray studies show that carbonate minerals are aragonite, high-Mg calcite, and lesser dolomite, ankerite and siderite. Aragonite is acicular, elongate and fills voids of the carbonates. High-Mg calcite is granular. The δ~(13)C values of carbonates range from -56.878‰PDB to -32.829‰PDB, most less than -40‰PDB, suggesting a microbial methane-associated carbon reservoir. The δ~(18)O values of carbonates range from 2.1875‰PDB to 5.045‰PDB, giving a heavy value of O isotope ratios and indicating a ~(18)O-enriched water resource. Studies of the mineralogy and oxygen and carbon stable isotopic compositions provide clues that the carbonates from the offshore area of southwest Taiwan were probably precipitated from the cold seeps,which originated from gas hydrate dissociation.[KG)]