Tungsten ore
The deposit is related to the second and three-stage magmatism in the early and third stages of the Yanshanian. It is known that the mineralization is mainly in the second-stage intrusive fine-grained granitic and third-stage intrusive fine-grained granites. The two-stage intrusive rock is produced by irregular rock or rock, and partly in the form of a dike-like output, and the multiple stages of the magmatism result in the complex structure of the rock mass and the superposition of the mineralization. The third stage of the intrusion of fine-grained granite, in addition to the tungsten ore, is associated with mineralization and mineralization. The ore minerals mainly include wolframite, scheelite, genectite, goethite, black and rare gold deposits, and other rare earth minerals. The ore has a fine grain structure and a compact and massive structure. The useful minerals are disseminated in the form of disseminated or fine-vein. The sedimentary vein disseminated type is pass tungsten deposit, which is a small scale and occurs in the external contact zone of Tieshanlong granite strain invaded in the early second stage of Yanshan. the ore-bearing strata are sandstone and mudstone of the Lower Devonian Zishan formation, and there are NE faults nearby. The surrounding rock of rock mass suffers from strong thermal metamorphism and hornstone development. The orebody is layered, and the lens or capsule occurs in the sand with strong hornization and shale interlayer in the middle and lower part of Zishan formation of Lower Carboniferous, in which the silty layer mineralization is strong, and the occurrence of orebody is consistent with that of surrounding rock. The ore minerals are mainly composed of wolframite, symbiotic minerals such as cassiterite, chalcopyrite, pyrite, topaz, tourmaline, quartz and fluorite. Tungsten and tin minerals are disseminated in veinlets, and the ores are silty, powdery and metasomatic. They have massive, banded, hollow and honeycomb structures, and generally preserve the structural characteristics of surrounding rocks. The broken zone type is found in pangu mountain tungsten deposit and longdeng mountain tungsten deposit.The broken belt type mineralization of pangushan tungsten deposit was revealed by the second hole drilled by nanling science (sp-nlsd-2) (fang guicong et al., 2014).Longdanshan tungsten deposit is located in the outer contact zone of early yanshan granite intrusion.Due to the development of fault structure near the ore point, a certain scale of fracture zones and fracture zones are formed.The tungsten-containing fracture zone is mainly composed of various irregular fractures in the nw fracture zone and interlayer fractures in the surrounding rocks. The tungsten-containing vein body includes tungsten-containing veins, quartz veinlets and quartz feldspar veins. The tungsten-sand mine is more important in the area of the upper-iron mountain area, and is found in the eluvium, the slope and the alluvium. The eluvium is formed from the weathered residual of the bedrock, and the composition of the debris is consistent with the bedrock. The top of the slope is divided from the bottom to the bottom of the surface layer, the gravel layer and the sandy clay layer, and the bottom is the bedrock weathering layer. The eluvial sand ore is distributed in the vicinity of the primary ore deposit, the distribution range is not large, but the ore-bearing property is good and has a certain economic significance.
