| To study the deep faults of crust through geophysics not only provides proofs to further study of basic theories such as the crust evolution and continent formation, but also provides an important guidance to classifying tectonic units, analysing and predicting natural earthquake activities and studying different kinds of mineralisation.After comprehensive interpretation of geophysical information, on the basis of equal depth on Moho discontinuity, a new conception that the first order fault system (FOFS) of mid-Asian region has a tow-upheaval-two-concave-shaped structural framework, which called suture, is put forward for the first time. It is also concluded that the area along the each side of the FOFS has potential for precious and nonferrous metal deposits, while the sedimentary basins located in the middle of the FOFS are the ideal targets for looking for oil and gas.With further study of the deep faults interpreted through the data of aeromagnetic survey, Bouguer gravity, satellite magnetic, DEM, modern earthquake and seismic tomography, the deep fault framework in mid-Asia was classified into five different depths from 210km, 130km, 50km, 20km to shallow ground surface. The paper suggests for the first time that the geological blocks with different properties in midAsian area are determined by three groups of principle basement faults(PBF), they are: east-westward, north-eastward and north-westward faults. Author believes that these three group faults of PBF layout at the depth of 50km with a space of about 1000km between them; and at the depth of 20km, several groups of deep fault networks derived from the PBF with nearly equal space, which layout with an space of about 200?00km. The suggestion of these three groups of PBF has significant meaning in the study of tectonic of mid-Asian area.After the study of the basement faults of two inland sedimentary basins - Junggar and Tarim basins, it is believed that Precambrian basement lies deep in these two basins which are controlled by the three above-mentioned PBF and destroyed by the faults on north-westward and north-eastward. Tarim basin in particular, it is previously known that Tarim basin should be an complete piece of unbreakable iron. While in fact the central latitude fault of Tarim eventually was deeply cut by the northwestward movement, which pushed blocks on east of 820 to north at a distance of 50km. This discovery will be greatly helpful in the researches on the basement tectonic of Tarim basin.On the basis of the study of geophysical field, basement faults and occurrence of world class deposits in mid-Asian area, this paper focuses on discussing the basic principles of looking for major and world class deposits in these area. The principlesare:?The major and world class multi-metal deposits are determined not only by the sutures but also by three group faults of PBF;?Major and world class deposits lie at the each side of sutures, depicted as FOFS, and at the joints of the three group faults of PBF.The principles supply a basis for minerogenetic prediction of the major and world class multi-metal deposits in mid-Asian area, specially in Xinjiang. The author believes that the secondary order fault system with a space of 1000km control minerogenetic provinces that have potential for discovering world class deposits in mid-Asian area, and then points out that the two typical minerogenetic provinces are:southwest Tianshan area and Altay area. It is also believed by the author that the third order fault system with a space of 200km determine mineralization zone in mid-Asia. Three areas are predicted by the author to have the potential of discovering major deposits. They are: mineralization zones in southern Altay mountain, southern Tuha basin and southern Tianshan.This paper collects the latest data in different fields of geological researches on mid-Asian area such as regional geology, Bouguer gravity, aeromagnetic, satellite magnetic, DEM, seismic tomography, modern earthquake, isotope age, deposit occurrence. In this...
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