A New Report of Serpentinites from Northern Central Indian Ridge (at 6oS) — An Implication for Hydrothermal Activity |
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作者姓名: | Dwijesh RAY Ranadip BANERJEE Sridhar D. IYER Subir MUKHOPADHYAY |
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作者单位: | Geological Oceanography Division, National Institute of Oceanography, Goa 403004, India;Geological Oceanography Division, National Institute of Oceanography, Goa 403004, India;Geological Oceanography Division, National Institute of Oceanography, Goa 403004, India;Department of Geological Sciences, Jadavpur University, Kolkata 700 032, India |
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基金项目: | This research is partly funded by ONR grant No. 0014-97-1-0925 and CSIR Network Programme (COR 0006) on Indian Ocean ridges. |
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摘 要: | Serpentinites from the inside corner high (6°38.5′S/68°19.34′E) from the Northern Central Indian Ridge (NCIR) are comprised mainly of high Mg-rich lizardite and chrysotile pseudomorphs with varying morphologies. 'Mesh rim', 'window', 'hourglass' and 'bastite' are the most common textures displayed by both chrysotile and lizardite. Numerous chrysotile veins in association with cross cutting magnetite veins indicate an advanced stage of serpentinisation. The relatively high abundance of chrysotile and lizardite suggest their close association and formation at a temperature below 250℃. Abundant 'mesh rim' and 'bastite' texture and variegated matrix reveal that the present serpentinites might have formed due to the interaction of harzburgite and seawater. Positive Eu anomaly (Eu/Eu^* up to +3.38), higher La/Sm (up to 4.40) and Nb/La (up to 6.34) ratios suggest substantial hydrothermal influence during the formation of the serpentinites.
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关 键 词: | 蛇纹岩 水热蚀变 地质构造 地质学 |
收稿时间: | 2007-04-30 |
修稿时间: | 2008-01-22 |
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