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

摘要： 研究了塔里木盆地志留系的沉积特征、构造特征与演化,以及沥青砂岩在志留系的分布规律。塔中地区志留系在纵向上分为三个储盖组合。塔中、塔北及柯坪三大古隆起控制着沥青砂岩的分布。在塔中地区志留系沥青砂岩主要分布在五个次级构造带上,塔北地区的均分布在晚加里东期的区域隆起部位。研究还表明,塔里木盆地志留系沥青砂岩的分布均受控于泥岩盖层和物性,两种情况都说明这些沥青砂岩主要为古油气藏破坏的产物。志留系砂岩中沥青分布在微观上有两种赋存状态:一种是块状,另一种是浸染状。在偏光镜下,可分为油质沥青(晚期)和胶质—沥青质沥青(早期)两种,两者常常共存,含量为互补关系。

关键词: 塔里木盆地, 志留系, 沥青砂岩, 沉积, 构造, 分布特征