Metallogenic Condition Studies On Dongpo Tungsten Deposit Of Shangri-la County In Yunnan Province

The Dongpo Tungsten deposit located in Dongpo village, Hutiaoxia town, about80 km south to Shangri-la County in Yunnan province,with the regional tectonic setting of south portion of Songpan-Ganzi fold belt. The deposit was controlled by the thrust faults in the hanging wall of Jingshajiang deep fault.Based on the previous studies and the systematic studies in this paper on geological survey and explorations, the results suggested that the volcaniclastic rocks inter-beded with carbonate could be the original source rocks for tungsten. Due to the regional metamorphism and long-term tectonic movements of Haba-Yulong Orgeny, the interlayer expension and stripping on both sides of the thrust faults provided ideal space for ore-forming solution migration and enrichment. Tungsten ore bodies as sheelite layers,hosted in upper Permian basic volcanic rocks and in middle Triassic volcaniclasitic rocks,were controlled by interlayer fracture zones, cleavage belts and alteration zones on both sides of F2 thrust fault.Early secondary fracture zone and interlayer fracture zone were superimposed by shear cleavage belts, which provided the favorable channels for ore-formation fluids and wall rock alterations and yielded the tungsten mineralization in alterated volcaniclasitic rocks. Therefore, the Dongpo tungsten deposit was recongzied as the middle to high temperature sedimentary-hydrothermal reworking deposit with the possible mineralization age of early Himalaya epoch.