卫星照片的线性破裂解译

为了研究大地震发生的地质构造背景,卫照分析是很重要的。我们解译了鄂尔多斯周围和华北地区的卫星照片。共解译出巨、大、中、小各类线性破裂4737条,发现它们的最新活动表现在:1.继承性:即新的破裂沿袭中生代以前的老断裂活动;2.新生性:部分破裂在第三纪特别是第四纪形成。两种表现在卫片影象上都相当清楚。我们认为这些由卫照识别出最新活动断裂与地震活动有一定关系。

THE INTERPRETATION OF THE LINEAR FRACTURES ON THE LANDSAT PHOTOES

The linear fractures so called by this paper are a series of images of straight lines on the LANDSAT''s photoes, and most of them are caused by tectonic activities, such as fault-controlled river systems, offset streams and ridges, subsidence lake basins and grabens, deviational alluvial fans, straight seashore lines and somemicrofractures which may result from the recent crustal movement. Therefore, the word "fracture" can not be limited to geological faults.We inlay and interpret 123 photoes from LANDSAT-1, 2, 3, in the region between E 104°-122°and N 34°-41°, which covered 1.36 million km². The photoes used by us are coarse and black-white, so there are errors of 6-7mm in our inlay. The density slicing had been done in part of the typical photoes. In order to check our interpretation, some field examinations have been carried out. We discover that the activities of all kinds of the fractures in the latest geological time were shown into two aspects:1. Continuity. Most of the fractures activities occur along the old faults of pre-mesozoic era.2. Originality. Part of the fractures originated in the Neogene period, especially in the Quarternary era.All the characteristics as mentioned above are eyecatching on LANDSAT photo images.In the course of our analysis, we find that in the whole region of North China, various typies of fractures are shear, particularly in recent tectonic stress field. In spite of their criss-cross each other, they are in order and fall into three groups of conjugate systems, e. g. EW/NS, NNE/NW-NWW, NNW/NE-NEE. Finally, the authors have tried to find out the relationship between the seismicity and the linear fractures.