鄂尔多斯盆地杭锦旗地区构造单元划分新方案及地质意义

Dicussing on Division Scheme of Sub-tectonic Units in Hangjinqi Area,Ordos Basin and the Geological Significance

构造单元的划分对明确杭锦旗地区内部基本构造特征、深化地质认识、指导油气勘探具有重要意义。对原构造单元划分方案中存在的问题进行了剖析;并据近年来的钻探和地震解释成果以大断裂及其走向趋势线、下古生界尖灭线、基底起伏形态及-2 500 m海拔为依据,对基底断裂及地层展布特征进行了论述。对杭锦旗地区构造单元边界划分进行了探讨。与原方案相比,下古生界尖灭线和坳拉槽特征的界定使二级构造单元的划分更趋合理。该划分方案对于杭锦旗地区下一步天然气勘探具有重要的指导意义。

Studies on division sub-tectonic units are of great significance in clearing the character of tectonic,deepening of the geological understanding,and guiding oil and gas exploration in Hangjinqi area.The original division scheme is analyzed and a new scheme is presented according to the drilling result and seismic interpretation result of recent years.Based on the study on the large fault and its the trend line,Lower Paleozoic pinch-out line,bedrock undulating morphology and-2 500 m above sea level （datum 1 500 m）,analyzing characteristics of bedrock fault and strata distribution,discussing border demarcation tectonic unit in Hangjinqi area.Compared with the original scheme,the sub-secondary tectonic unit division is more reasonable according to defining of the lower Paleozoic pinch-out line and aulacogen characteristics.This new scheme for the redivision of structural units is of great significance to future gas exploration in the study area.