巴里坤盆地晚古生代火山岩年代学及构造演化

Volcanic chronology in Neopaleozoic and structural evolution of Balikun Basin

与周缘相邻的含油气盆地相比,前人对巴里坤盆地的研究少之又少,对其认识也不够完善;特别是由于缺乏化石及年代学资料,对研究基础的地层划分方案也一直存在争议。本文通过LA-ICP-MS单颗粒锆石U-Pb同位素测年方法对盆内Bal井岩心取样的凝灰岩进行了年代学测定,依据测定结果并结合地震反射同相轴特征对巴里坤盆地的地层重新进行了划分,从下到上由上石炭统、二叠系、第三系及第四系组成,缺失了整个中生界地层。盆地内的构造相对简单,断裂以地堑式和阶梯式组合为主,地层仅轻微褶皱且地层厚度及埋深向东及向北减薄、变浅。

Compared with other adjacent petroliferous basin, Balikun Basin is hardly researched. Because there is a lack of fossil and chronologic data, the stratigraphic division is still disputed. Using the U-Pb isotopic dating of single zircon,absolute data of tuff samples from Bal well is tested. According to the chronologic test results and characteristics of seismic reflection event, the stratigraphic is divided newly. The sedimentary cover is composed of Upper Carboniferous, Permian, Tertiary and Quaternary and lack of all the Mesozoic. The structure of Balikun Basin is very simple. Faults styles are mainly graben and step fault. Strata are little folded. Strata thickness and buried depth both decrease eastward and northward.