Gejiu Basalt And Mineralization

The history of gejiu tin mine area development is long, and the geology research degree is higher.But a lot of research which has been done makes a point of granite mineral theories and modes establishment, thought that gejiu tin mine area metalses deposit is main to have something to do with yanshan period granite, and mineralization time concentrates in yanshan later period. This paper through the gejiu stratum, basalt and lithology of granite, rock chemistry, geochemistry analysis and The district geology synthesizes research, the following cognitions are obtained:1. The basic volcano activity and how many times have been investigated this time. The basalt in gejiu tin mineral area Distribute in middle Trias group and falang group, at least contain three periods and several gyration functions. The earliest Period basalt is in the gejiu group.lying in the gejiu group next segment. (T₂g1¹) in east gejiu area distribute in xinshan kafang, laochang and south qiling village, the area roughly covers 125 square meter; the second period volcano rock is located in gejiu west area next segment of falang group,( T₂f¹) which involves primarily two layer, The thickness is roughly 70m, and with the charcoal-marlite, argillite each other. They distribute in shuitang stockaded village, baohe and muhuaguo, roughly cover 40 square meter; the third period volcano rock is located in gejiu west area next segment of falang group( T2f1), and with the shale, marlite each other, distributing in tabai and feigulong,specially in tabai.2. As a whole, the elevation of basalt's top ceiling position is generally lowing from north to south. And the basalt affects by the region basalt distribution, it distributes along north-east. Generally speaking, the basalt's position is lower in the joint between weiniutang faultage and banpo faultage, the elevataion about 1800m. But the position is higher in the joint between xianrendong faultage and xinshan faultage, about 2000m. In the south of the xinshan faultage, the basalt's elevatation becomes low, and about 1850m. And in the north-east of here, the big white rock basalt's top ceiling becomes high again, the elevation about 2100m, and near the laoxiongdong faultage, the basalt's position is lowest, 1700m or so. In the north of lalihei faultage, the basalt's elevation becomes high quickly, and in the zhuyeshan the position is highest, about 2200. in laochang mineral field white tiger, the basalt has the same position. The basalt's rock can be divided into three types. That is lava, melt-combine tuff and basalt tuff. The lava is of nubbly, sheet, air vent and amygdale structure and graininess change crystal, squama change crystal, change remainder spot configuration. Most of The melt-combine tuff have metamorphosed squama actinolite phlogopite rock and phlogopite actinolite rock. The basalt tuff metamorphosed squama sericite phlogopite changing alkalescence basalt tuff or phlogopite changing alkalescence basalt tuff, and the phlogopite content covers 60 percent.3. In east gejiu area, the basalt mainly lies in lower segment in gejiu group (T2g1¹), and presents with the carbonate rock each other. When granite body intrudes into the lower segment in gejiu group (T2g1¹), carbonate rock's chemistry character is active, and the basalt's not so active, so carbonate rock is more easily eroded, add the basalt still locates there, thus makes granite's sunken structure. At the same time basalt is heated by the magma, and then happens metamorphose, as a result the element Cu is becoming enrichment, forming basalt type Cu mineral. The granite body with "mushroom shape" in laochang mineral field and "pagoda shape" in zhuling mineral field and sunken mineral body shape are all controlled by the basalt. the east, west sunken zone in zhuling laochang field is also controlled by the basalt.4. According to above mineral-forming forecast principle, protract basalt coping, bottom isoline graph, in the basis of comprehensive analysis, put forward 4 beneficial mineral-forming area, finally analysis foreground in this 4 forecast area.