重力场多尺度刻痕分析与满加尔坳陷深层构造  

Multi-scale Scratch Analysis of Gravity Field and Deep Structures in Manjar Depression

作　　者：杨文采[1] 孙艳云[2] 于常青[1] 侯遵泽[3] 

机构地区：[1]“大地构造与动力学”国家重点实验室、中国地质科学院地质研究所,北京100037 [2]中国地质大学地球物理与信息技术学院,北京100083 [3]中国人民武装警察部队学院,河北廊坊065000

出　　处：《地质学报》2015年第2期211-221,共11页Acta Geologica Sinica

基　　金：中国地质调查项目(编号:12120113093800)资助成果

摘　　要：区域高精度重力场测量可以获得关于沉积盆地深部构造的丰富信息。本文在分析满加尔坳陷内部深层构造探测存在问题的基础上,开展了重力测量,并采用重力异常的小波多尺度分析和刻痕分析等新方法,研究了满加尔坳陷内部深层构造,揭示了坳陷内早古生代地层的密度分带。应用小波多尺度分析方法可以把只与深层构造有关的地质信息提取出来。运用新的人工智能原理把隐含在区域重力场中有关刻痕的所有特征参数提取出来,可以客观地为沉积盆地内部构造单元划分提供可靠依据。结合区域重力场多尺度分析及刻痕分析的信息提取新方法,称为多尺度刻痕分析。比较研究区深层（7~8km）密度扰动与电阻率异常可见,满加尔坳陷内沿纬度40°线北侧和经度85°线同时都有低密度扰动和低电阻率异常分布,说明坳陷内深层沉积岩低密度扰动与流体活动通道有一定关系。综合脊形化系数图和边界刻痕系数图,圈定了深层满中高密度扰动带和满南和满北低密度扰动带,为深层油气勘探提供重要基础资料。Regional gravity data contain rich information about deep structures in sedimentary basins.After analyzing problems that occur during oil/gas exploration in Manjar depression within Tarim Basin,we complete dense measurements of surface gravity investigation in the depression,then use wavelet transformation and scratch analysis methods to study deep structures,locating the density disturbance belts exist in early Paleozoic strata.By applying the wavelet multi-scale decomposition method to regional gravity data,we are able to extract information only related to deep structures.By applying an artificial intelligence method called scratch analysis,we are able to recognize characteristic parameters about scratches contained in regional gravity field,providing objective evidences for dividing tectonic units within the basin.The combination of these two methods is called the multi-scale scratch analysis method,producing both the ridge parameter and scratch-edge maps for both shallow and deep structures in Manjar depression.Comparing the map of density distribution with MT electrical resistivity on depth of 7~8km,we find that anomalies of both low density belts and low resistivity belts occur along latitude 40°and longitude 85°,showing the correlation between the low density distributions and ancient fluid channels.The results from the multi-scale scratch analysis indicate that there are some sub-tectonic units exist in the deep Manjar depression,their location provide some important basic data for deep-strata oil/gas exploration in the depression.

关 键 词：区域重力场 小波多尺度分析 刻痕分析 塔里木盆地 满加尔坳陷 密度扰动带 深层构造 

分 类 号：P618.13[天文地球—矿床学] P631.1[天文地球—地质学]