A New Report of Serpentinites from Northern Central Indian Ridge(at 6°S)—An Implication for Hydrothermal Activity

作     者：Dwijesh RAY Ranadip BANERJEE Sridhar D.IYER Subir MUKHOPADHYAY 

作者机构：Geological Oceanography DivisionNational Institute of OceanographyGoa 403004India Department of Geological SciencesJadavpur UniversityKolkata 700 032India 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2008年第82卷第6期

页      面：1213-1222页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 0708[理学-地球物理学] 

基　　金：funded by ONR grant No.0014-97-1-0925 CSIR Network Programme(COR 0006)on Indian Ocean ridges 

主　　题：serpentinite serpentinisation hydrothermal alteration 

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.