关键词: 塔里木盆地, 志留系, 沥青砂岩, 沉积, 构造, 分布特征

Abstract: The depositional and structural characters and the tectonic evolution,as well as the distributional patterns of bituminous sandstone of the Silurian in Tarim Basin were studied in detail in this paper.In Tazhong area,vertically,the Silurian can be divided into three sets of reservoir/cap rocks combination.The three paleo-uplifts of Tazhong,Tabei and Keping controlled the bituminous sandstone distribution in the basin.In Tazhong area,the Silurian bituminous sandstone are mainly distributed in five sub-structural zones, and in Tabei area,all distributed in regional uplifts of late Caledonian.The study also shows that the distribution of the Silurian bituminous sandstone in Tarim is controlled by the distribution and physical property of muddy cap rocks,and these indicate that the bituminous sandstone are mainly the products of the destroyed palaeo-oil pools.Microscopically,there are two types of occurrence for the bitumen in the Silurian sandstones:one is massive,and another is disseminating.Under polarizer,two kinds of bitumen,oily(late hydrocarbon filling) and colloidal/asphaltic (early filling),respectively,can be observed,and both of them often coexist and their amounts are complementary.

Key words: Tarim Basin, Silurian, bituminous sandstone, deposition, structure, distribution character