Abstract: The Upper Triassic Riganpeicuo Formation(Carnian-Rhaetian)is composed of a thick set of fossil-rich carbonate rocks at the Renacuo area，Gaize，Tibet. Eleven major types of carbonate rocks were identified, i e.， marlite，bioclastic mudstone，bioclastic wackestone，bioclastic packstone，intraclastic packstone，intraclastic grainstone，algal grainstone，multi-types of oolitic grainstone，single-type of oolitic grainstone，pellet packstone and reef limestone. According to the petrological characteristics and assemblage types，five sedimentary facies were divided: Terrigenous detrital littoral facies，restricted-platform facies，open-platform facies，platform edge bank facies and platform edge reef facies. They constituted the four transgressive-regressive cycles of the Riganpeicuo Formation，which overall showed a facies sequence of transgression.

Key words: carbonate, sedimentary environment, Upper Triassic, Riganpeicuo Formation, Tibet Gaize

摘要： 西藏改则县热那错东沟剖面上三叠统卡尼阶至瑞替阶日干配错组沉积了厚度较大的碳酸盐岩地层，其中化石丰富。在碳酸盐岩中识别出11种主要的岩石类型：灰泥灰岩﹑含生物碎屑灰泥灰岩、生物碎屑粒泥灰岩、生物碎屑泥粒灰岩、内碎屑泥粒灰岩、内碎屑颗粒灰岩、藻颗粒灰岩、多种类型鲕粒灰岩、单一类型鲕粒灰岩、球粒泥粒灰岩和生物礁灰岩。根据岩石特征及组合类型可划分为5种沉积相：陆源碎屑滨岸相、局限台地相、开阔台地相、台地边缘浅滩相和台地边缘礁相，它们共同构成了日干配错组4个有序的海侵—海退旋回，整体显现出海侵的相序结构。

关键词: 碳酸盐岩, 沉积环境, 上三叠统, 日干配错组, 西藏改则

CLC Number: 

• P588.24＋5