New results of investigation on manganese ores in the Lô Gâm area (Tuyên Quang - Hà Giang)
Trần Văn Quý, Nguyễn Đình Mộc
In the Lô-Gâm area (Tuyên Quang and Hà Giang Province) many valuable mineral occurrences were discovered, among them there is the Làng Bài (Tuyên Quang) and Đồng Tâm (Hà Giang) manganese deposits of promising industrial scale. The survey and assessment of minerals is being carried out by the East Bắc Bộ Geological Division in the Đồng Tâm area. Combined with the results of geological mapping at 1/200,000 and 1/50,000 scales and of investigation, evaluation and exploration of minerals in larger scale, a lot of materials on the process of creation and distribution of manganese ores in the area have been supplemented. The manganese ores of sedimentary origin located in the member of quartz schist and quartzite are of poor content. Those of weathering and precipitation origin are located over the ore-bearing member have richer content. The main composition of manganese ores consists of Mn = 8-31%; Fe = 6-34%; the thickness of ore-bearing member is from 0.5 to tens of metres, and its ldài từ chục mét đến hàng ngàn métength – from tens to thousands of metres.Quặng phân bô trong đới cà nát của đứt gẫy tạo nên 2 đới quặng dạng chuỗi mạch không liên tục theo phuơng đông bắc tây nam và phuơng tây bắc đông nam. Manganese ores form two ore zones of discontinuous veins and vein lattices, extending in the NE-SW (Đồng Tâm) and NW-SE (Làng Bài) directions. Based on study results, the survey, evaluation, exploration and proposals on the use of manganese ores from this area have been set forth.
Người biên tập: Trần Tất Thắng