塔里木盆地下奥陶统白云岩特征及成因

Characteristics and Origin Analysis of Dolomite in Lower Ordovician of Tarim Basin

在整个地质历史中，有两个白云岩分布的高峰期，即中生界和下古生界。塔里木盆地寒武一奥陶系白云岩按其结 构可分为七种类型，而且它们的碳氧同位素值也有较大的差异，微量元素的含量高低悬殊，包体均一温度差值幅度大， 充分反映其成因的差异。按其岩性特征、碳氧同位素值、微量元素的含量和成岩温度可分为准同生白云岩、浅埋藏白云 岩和深埋藏白云岩三类。

There might be two major stages in dolomite distribution throughout geologic history of Tarim basin, that is, Mesozoic and Early Paleozoic. The dolomite of Cambrian--Ordovician could be classified into seven types by its structures. The following big differences display its variations in origin, such as carbon and oxygen isotope value, trace element content and inclusion homogenization temperature range. Based on lithology, carbon and oxygen isotope value, trace element content and diagenetic temperature, it can also be classified as penecontemporaneous dolomite, shallow buried dolomite and deep hurled dolomite.