塔中地区中下奥陶统白云岩特征及成因

Characteristics of Middle to Lower Ordovician Dolomite in Central Tarim Basin and Its Origin

塔里木盆地塔中地区中下奥陶统的白云岩是塔里木盆地天然气勘探的重要后备领域。关于其白云岩的成因一直存在着一些分歧。在总结前人研究成果的基础上,结合笔者研究的实际情况,通过岩心及显微镜下观察将塔中中下奥陶统的白云岩划分为4种类型。通过对其岩性特征、阴极发光、微量元素、碳氧稳定同位素、锶同位素的分析,认为存在热液、浅埋藏、渗透回流和大气水—海水混合白云石化机制。

Middle to Lower Ordovician dolomite in central Tarim Basin becomes the main standby domain for gas exploration in Tarim Basin.But,there is some dispute about dolomite origin.Integrated previous achievements and authors research,the Middle to Lower Ordovician dolomite could be divided into four types after core and microscopic observation.The lithologic characteristics,cathodoluminescence,trace element,C/O stable isotope and Sr isotope were analyzed.And it is considered that there are four mechanisms including hydrothermal,shallow bury,seepage reflux and meteoric water-seawater compound dolomitization.