塔里木盆地塔中地区奥陶系地层沉积特征

新疆塔里木盆地塔中地区是重要石油天然气产区。奥陶系是烃源岩，也是主要勘探层系之一，具有分布广，纵、横向变化大的特点。下奥陶统与寒武系相似，碳酸盐台地发育，以灰岩、白云岩为主。中上奥陶统岩性分区以塔中Ⅰ号断裂为界，分为两大地层、岩性区。为碳酸盐台地与外源碎屑岩同时发育时期。寒武－下奥陶统是该区分布最广的烃源岩，中上奥陶统烃源岩只分布在浅海台地区。

Sedimentary Characteristic of the Ordovician Strata in the Area of the Middle Tarimu Basin

The area of the middle Tarimu Basin is an important oil-gas province. The Ordovician is the hydrocarbon source rock and also is one of the main series of stratum in exploration, which is characterized by wide distribution and greatly vertical-horizontal variation. The lower Ordovician is similar to Cambrian, the carbonate platform developed and the tuff and dolomite rocks are in major. The lithology division of the middle-upper Ordovician has the No.1 fault in the area of the middle Tarimu Basin as the boundary, which is divided into two strata and lithology areas. The carbonate platform and accident clastic rocks developed simultaneously in this period. The Cambrian-lower Ordovician is the widest sources rock in the areas and the middle-upper Ordovician source rock just distributed over the sub-sea terrace.