鄂尔多斯盆地东南部黄陵地区延长组裂缝特征及形成期次探讨

通过野外露头和岩心观察,黄陵地区裂缝发育,主要是垂直缝和高角度缝。裂缝在区域内分布稳定,属于区域构造裂缝。裂缝主要以未充填为主,有效性高。结合裂缝发育特征及区域应力背景,采用岩石声发射实验、裂缝充填物稳定碳氧同位素、流体包裹体分析等实验手段,综合分析认为黄陵地区延长组存在三期裂缝,分别对应为燕山期二幕,燕山期三幕和喜山期,现今裂缝分布是在燕山期构造作用的基础上经过喜山期改造而形成。

Fracture Characteristics and Stages of Yanchang Formation in Huangling Area of Southeastern Ordos Basin

According to the observation of outcrops and core,the fracture development of Huangling area are mainly vertical fractures and high angle fractures. Its belongs to regional structural fractures that relatively well developed. The fractures are mostly unfilled. The effectiveness of fractures are particularly high. Based on the characteristics,background of regional stress and experimental tests,such as rock acoustic emission experiment,carbon-oxygen isotopic analysis and fluid inclusion tests of fracture fillings,reveal that the fractures in Yanchang formation of Huangling area were formed in three stages,which are corresponding to the second and the third episodes of Yanshanian,the episode of Himalayan. The distribution of present fractures is the result of Yanshanian structural action and Himalayan Movements transformation.