Characteristics of copper ores in the Tri Năng area, Lang Chánh District,
Thanh Hóa Province

Hồ Văn Tú

The Tri Năng area, Lang Chánh District, situated in the western mountainous zone of the Thanh Hóa Province, has a complicated geological structure with polymorphous magmatic manifestations and strong tectonic activities. At present, many copper ore occurrences related to gabbro of the Núi Chúa Complex have been discovered, among them the Trí Năng occurrence is of greatest significance.

The copper mineralization in Trí Năng is of hydrothermal origin, distributed along cataclastic zones in gabbro, or in the contact boundary between gabbro and sediments of the Đồng Trầu Formation. Copper ore bodies have the main mineral composition (%) of: pyrite = 0.1-10; chalcopyrite <0.1-7; pyrrhotine = 1-10; covelline <0.1; galenite = 0.1-5; sphalerite = 0.1-0.4; besides, there still are melnicovite, goethite, magnetite; rare minerals are chlorite, siderite, sphene, garnet and calcite (vein minerals).  Content of Cu: 0.232-4.21%.

Hydrothermal alteration processes accompanying the copper mineralization strongly and complicatedly occurred, consisting of quartzification, sulphidization, carbonatization and skarnization.

Người biên tập:  Trần Đình Sâm.