川东北Y地区雷口坡组古岩溶辨识标志  

Identification Marks of Paleokarst of Leikoupo Formation in Y Area,Northeast of Sichuan

作　　者：刘雁婷[1,2] 傅恒[2] 陈骥[2,3] 刘欣 达丽亚[2] 

机构地区：[1]中国石油化工股份有限公司勘探南方公司,成都610041 [2]成都理工大学能源学院,成都610059 [3]中国石油天然气股份有限公司西南油气田公司,成都610051

出　　处：《地质科技情报》2011年第4期120-126,共7页Geological Science and Technology Information

摘　　要：川东北Y地区三叠系雷口坡组沉积后,受三叠纪印支I幕运动的影响,Y地区抬升,缺失部分上三叠统、部分中三叠统,与上覆上三叠统须家河组呈区域性平行不整合接触,接受大气淡水淋滤,为古岩溶的形成提供了有利条件。通过对研究区钻井资料、测井资料的分析,借助岩心观察与岩石薄片,以及电子探针、阴极发光、碳氧同位素等测试手段,综合分析和研究了风化壳岩溶发育特征,可识别出下列6种岩溶标志:地层缺失标志、钻录井标志、测井标志、岩石学标志、古生物标志以及地球化学特征。结果表明雷口坡组第四段碳酸盐岩受岩溶作用改造强烈,岩溶现象丰富。Y地区及其邻区雷口坡组岩溶发育的控制因素可归结为外因和内因两个方面,外因主要表现为构造作用对溶蚀的主动影响,内因表现为雷口坡组可溶岩本身对溶蚀的被动影响。After the deposition of Triassic Leikoupo Formation in Y area, northeast of Sichuan, the area was uplifted because of the Triassic impact of Indo-I movement, and missed upper and middle parts of the Triassic, and formed a regional parallel unconformity with the overlying Triassic Xujiahe Formation. The weathering of this area provided good condition for the formation of paleokarst. This paper studies comprehensively the weathering crust karst based on the analysis of 8 wells drilling data and log data, the cores and thin sections by means of electron microprobe, cathodoluminescence and C / O isotopes. Six karst marks are identifiedsequence missing（stratigraphic break）, drilling, logging, lithology, paleontology and geochemical characteristics. Results show that carbonates in member 4 of Leikoupo Formation is transformed intensively by karstification. The controlling factors for the karst development of Leikoupo Formation in Y area and its adjacent areas can be summarized in two aspects. Externally, tectonism has an active impact on the dissolution and internally, the soluble rocks in Leikoupo Formation may react passively to the dissolution.

关 键 词：川东北 雷口坡组 古岩溶 辨识标志 

分 类 号：P642.25[天文地球—工程地质学]