【摘要】 根据岩性及其组合特征,本文将西藏北部安多—巴青地区侏罗纪含礁地层划分为流水成因的颗粒岩岩相、流水成因的碎屑岩岩相、复成因的泥晶—泥质灰岩岩相、生物及生物化学成因的障积岩岩相、生物及生物化学成因的粘结—障积岩岩相和生物及生物化学成因的骨架岩岩相等6大类型,计16种岩相。它们构成了潮坪相组合、台地浅滩相组合、开阔台地相组合和台地生物礁相组合共4种岩相组合,并由下而上有规律地形成2种岩相序列,即陆源碎屑与碳酸盐混合台地相序列和碳酸盐台地相序列。更多还原

【Abstract】 Based on the characteristics of lithologies and rock associations, the Jurassic reef-bearing strata in Anduo—Baqing area, northern Xizang (Tibet), could be classified into 6 groups of lithofacies: water current genetic grainstone, water current genetic clastic rock, polygenetic micritic limestone and marl, biogenetic and biochemical genetic baffling rock, biogenetic and biochemical genetic cemented-baffling rock, as well as biogenetic and biochemical genetic framestone. These lithofacies made up four kinds of lithofacies associations: tide plat, open platform, platform shoal and platform reef ones. The four lithofacies associations constituted two depositionary successions in ascending order, namely, the succession of mixed carbonate-terrigenous platform lithofacies and succession of carbonate rock platform lithofacies. Both of them indicated a relatively stable tectonic setting of shallow marine platform, different from the lithofacies associations and sedimentation of back-arc basin in Early Cretaceous.更多还原