湖南益阳玄武岩质科马提岩鬣刺结构的基本特征

来源期刊：中南大学学报(自然科学版)1987年第5期

论文作者：肖禧砥

文章页码：488 - 493

关键词：超基性岩； 枕状熔岩； 岩石结构； 橄榄石； 单斜辉石科马提岩； 鬣刺结构； 中空骸晶； 假象

Key words：ultrabasic rock； pillow lava； rock texture； olivine； clinopyroxene； Free terms； komatiite； spinifex texture； middle-spaced skeleton crystal； pseudomorph

摘    要：湖南益阳玄武岩质科马提岩的鬣刺结构是橄榄石、单斜辉石的中空骸晶呈放射状、束状、平行状、毛发状、丛状等晶团或晶群,排列于极细小的橄榄石、辉石、火山玻璃等物质组成的基质之中.橄榄石已蛇纹石化、滑石化、碳酸盐化等;单斜辉石变化较弱或已被透闪石化、绿泥石化等,基质已脱玻化,故此为鬣刺结构假象。橄榄石骸晶长0.25—0.75mm,宽约0.025mm;单斜辉石骸晶长0.1—0.5mm,宽0.025—0.05mm,属显微鬣刺结构.

Abstract: Spinifex texture of basaltic komatiite from Yiyang, Hunan, is composed of middle-spaced skeleton crystal of olivines and clinoaugites appearing as radiated, bundled, parallel, hair-like and crowded clusters lying in the matrix of extremely fine skeleton crystal of olivines and pyroxenes or glasses of volcano. The olivines are serpentinized, laicized, carbonatized. The clinoaugites are weakly alterated and tremolitized, chloritized. The matrix is devitrified. Obviously, that is a pseudomorph of spinifex texture. The skeleton crystals of olivines are 0-25—0.75mm in length (some up to 1mm), approximately 0.025mm in width. The skeleton crystals of clinoaugites are0.1-0.5 mmin legnth, 0.025—0.05mm in width. That is micro spinifex texture.