若尔盖拗陷红参1井中-上三叠统的岩石地层划分及地层特征

Stratigraphic division and stratigraphic characteristics of rocks in the Middle-Upper Triassic of Borehole Hongcan 1 in Zoige depression,Sichuan,China

红参1井是部署在若尔盖拗陷的1口重点参数井,钻遇地层为中-上三叠统的一套浊积岩,未获具鉴定意义的生物化石,属哑地层。在分析区域地质演化、区域地层划分的基础上,基于钻井过程中开展的严格而详细的跟踪取样分析,对1600余件样品分析统计,结合红参1井钻遇地层的基本特征,根据岩石组合、粒度统计、重矿物组合、岩石地球化学等特征,认为红参1井钻遇地层可划分为侏倭组、杂谷脑组及扎尕山组3个岩石地层单元。

Well Hongcan 1 is a parameter borehole drilled in Zoige depression,West Sichuan,China.Stratigraphy revealed by the data of Borehole Hongcan 1 is a suit of the Middle-Upper Triassic turbidities rock association without any fossil organism with diagnostic value.On the basis of analysing the regional geological evolvement and dividing the regional stratigraphic division,and based on the strict and detail sampling analysis during drilling,this paper analyzes and collects 1600 samples.Combined with the basic characteristics of the strata of Borehole Hongcan 1,and according to the characteristics of rock assemblage,grain-size statistics,heavy mineral assemblage and geochemistry of rocks,the paper thinks that the strata of Borehole Hongcan 1 can be divided into Zhuwei Formation,Zagunao Formation and Zanaishan Formation.