Cassiterite U - Pb isotope age of tin ore North Langsong deposit Tanky area, Nghean, Vietnam

Abstract

The North Langsong tin deposits are located in Tanhop commune, Tanky district, Nghean , and belong to the Phuhoat uplifted structure. This is the biggest tin ore area in the Northern and Central region of Vietnam. Tin accompanies quartz veins in the northeast - southwest fault zone, developed in carbonate rock formations . The main ore components include pyrite, arsenopyrite, cassiterite, and less commonly galena, chalcopyrite, magnetite, and secondary minerals such as limonite, goethite, and psilomelan. Authors used the results of LA - ICP - MS U - Pb cassiterite analysis to interpret the relationship between tin miner alization and granitoid intrusion. U - Pb analysis of cassiterite from the North Langsong tin deposits yielded isotopic ratios of 207 Pb/ 206 Pb - 238 U/ 206 Pb ranging from 0.0 000 to 1.2947 and from 0.0049 to 0.3626, with an age of 35.1 ± 5.2 Ma. On that basis, th e authors conclude that t he North Langsong ore deposits are associated with young (Paleogene) magmatic activity, represented here by granitoid rocks of the Ban Chieng complex .