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羌塘盆地位于青藏高原北部,为高寒缺氧的无人区,侏罗系大面积分布,三叠系零星分布,呈断块状产出,地层残缺不全,其中所含双壳、腕足、珊瑚、水螅类的时代跨度大,部分可延入侏罗纪。羌塘盆地中部晚三叠世地层由西藏区调队(1986)以肖茶卡剖面为代表命名为肖茶卡群,后改称为组,该组由下部砂砾岩段、中部碳酸盐岩段和上部砂泥岩段卡句成,时代定为晚三叠世,但缺乏晚三叠世代表分子,本文暂将其称为中部混积岩型肖茶卡组;随后在盆地的中北部照沙山、菊花山、甜水河等地发现岩性以碳酸盐岩为主的肖茶卡组,亦缺乏晚三叠世代表分子,本文暂将其称为中北部的碳酸盐型肖茶卡组。 笔者在北部的藏夏河、雪环湖和明镜湖等地发现一条呈近东西向断续分布的浊积岩相带,并在其中发现晚三叠世
The Qiangtang Basin is located in the northern part of the Qinghai-Tibet Plateau. It is an anoxic and anoxic zone with large area of Jurassic and sporadic distribution of Triassic. The Qiangtang Basin is faultless, with incomplete strata. The boulders, , Hydra class era spans large, some can be extended to the Jurassic. The Late Triassic strata in the central Qiangtang Basin were designated as the Xiaochaka Group by the Tiaichang Formation of the Tibetan Area (1986), and later renamed the group. The group consisted of lower glutenite, central carbonate And the Upper Sandstone and Mudstone Section, Kaducheng, the age is defined as Late Triassic, but lack of representatives of the Late Triassic. In this paper, we will refer to it as the middle diagenesis Xiaochaka Formation. Later, in the northern part of the basin, The discovery of the Xiaochaka Formation, mainly of carbonate rocks, also lacks the representatives of the Late Triassic in the mountains, Juhuashan and Tianshuihe. In this paper, we call it the carbonate-type Xiaochaka group. In the northern part of the Cangxia, Snow Ring Lake and Lake Mirror Lake and other places found a nearly east-west intermittent distribution of turbidite facies, and in which found the Late Triassic