The Research On Application Of Reflection Seismic Exploration For Thecrustal Structure In Ning-Wu Ore Concentrated Area

Mineral resources are not only the important material base of economic and social development, but also the strategic reserve is of great significance to national security. Although the total amount of mineral resources are large and types are varous in China, but our country is still facing a reality question, which is proven reserves of metal minerals are serious shortage. Furthermore, after a long time of exploration and development, the reserves of shallow resourcesare dwindling, the difficulty of shallow exploration is also gradually increasing. So exploration of deep mineral resources become an inevitable trend.Due to the limitation of exploration depth and precision, the conventional geophysical exploration technologies have some limitations, which are difficult to meet the needs of deep mineral exploration. As the core technology of deep exploration, reflective seismic exploration has the characteristics of high depth and high resolution. Reflection seismic exploration not only can solve the problem of deep structure in deposit exploration, but also it is one of the most effective techniques to detect the geological problems of fine crustal structure、magma activity of crustal interior、plate subduction or crust thrust at present and deep metallogenic dynamics.In this paper, author take the seismic reflection data of three lines(NW11-1, NW11-2 and NW11-3) as the main basis, which have be acquired in Ning-wu ore concentrated area, the lower of the Yangtze. Through the Tomographic imaging and processing of the data, and combined with the known geological data, the evidences of Ning-wu ore concentrated area’s deep crustal structure、deformation and magmatic activity are obtained. And it provides the basis for ore prospecting work in Ningwu ore district, at the same time, it also provides a useful clue for the research of the deep structure and kinetic process of the middle and lower reaches of the Yangtze River.The main understanding and achievement obtained are as follows:1、The shallow surface velocity structure information of the earth’s crust is obtained by the tomographic inversion velocity imaging, and the surface geological structure and lithology change are described.2、Discussed thefault system of "three vertical and four horizontal" in Ningwu ore concentrated area and analysed its shape and properties.3、There is an integrated and huge in horizontal distribution batholith at the crust beneath the Ning-wu volcano rock basin, and this batholith connected to magmatic intrusion area.4、The Ning-wu ore concentration area along fine structure of the crust is obtained, the reflection characteristics and the shape of the upper、middle and lower crust are characterized in this area, and the shape and position of the slip surface D which is located between the cover and the base in the middle of upper and middle crust are also given.5、Under the action of the stress field, the formation form subduction of the paleo Pacific platewhich is similar to the "alligator" structure is clearly visibled in these sections. It provides strong evidence for the study of the continental subduction processes in the middle and lower reaches of the Yangtze River.