The Study On Ore-controlling Structures Of Sanjiaotan Tungsten Deposit At Chuankou In Hunan Province

Sanjiaotan tungsten deposit lies in the southern edge of the SN-trending upheaval of Chuankou granites, which is the junction of the yangtze and cathaysia blocks. This area also is the superposition parts of the SN Leiyang-Linwu structures and the NE Liuyang-Hengdong structures. Due to a long-term geological tectonic evolution, the area is an important mineralized zone of endogenic metal deposits.Based on the predecessor’s achievements, detailed field geological surveys and interior data processing, the regional structures and the ore body’s shapes were studied at first. Then the formation and evolution of ore-controlling and their relationship with mineralization were systematically studied. Applying ore deposit theory, geochemistry and geomechanics theory and methods, the author made a comprehensive research on the ore-controlling factors of strata, magmatic rocks, structures et al. The tectonic geometry features, mechanical properties and dynamic genesis were analyzed from macroscopic and microcosmic perspectives. The formation, evolution and distribution of all levels’ore-controlling structures, as well as different levels of the structure for the control of mineralization, were analyzed in this paper. The author didn’t only study the relationship between tectonic and mineralization, but also established a structure ore-controlling mode. The metallogenic prognosis based on the theory of structure ore-controlling had been tested by engineering confirmation.According to the systematic studies, the main governing factors are the magmatic rocks and structures in this district especially that the main source of the ore-forming materials is the early Yanshanian granite body. The tectonic for the formation of the control of mineralization throughout the whole process of ore deposit formation. And the tectonic fractures not only provide access for the ore fluid migration but also provide occurrence space for the form of ore body. It is closely relate to the spatial orientation and the shape of rocks in the wolfram ore field, and the ore vein mostly developed in the upheaval of the rocks. The ore-controlling tectonic mainly include the ore-guiding tectonic and the ore-containing tectonic. The ore-guiding tectonic mainly formed in the occurrence of ore body and the neighborhood of wall rock’s contact plane, and it caused by the shrink of the cooling of magma and leading to tension crack and rift. The ore-containing tectonic has a complex mechanical feature which caused by three processing. In the early period, the original cross joints (Q-joints) were produced in the internal contact zone of the rocks body. In the later period, the invasion of magma moved from the earth’s deep to the surface. In the last period, the influence of tectonic activity made it have press-shear of mechanical feature.