Geochemical Characteristics and Geological Significance of Cassiterite in the Dalong Tin Deposit, Baoshan Block, SW China

Abstract

The Dalong tin deposit, located in the Luziyuan polymetallic ore field of the southern Baoshan block, Southwest China, is composed of lenticular and bedded orebodies hosted in a Cambrian slate-marble sequence. As the only tin deposit in the orefield, the genesis of the Dalong deposit is of great significance to the understanding of regional metallogenic regularity. Based on a systematic field survey and petrographic observation, EPMA and LA-ICP-MS major/trace element analyses of cassiterite were carried out in this study. The enrichment of Fe, W, and Ti in cassiterite, as well as the depletion of Nb, Ta, and Mn, reveal cassiterite’s features in granitic magmatic-hydrothermal deposits. The Dalong deposit can be categorized as a magmatic-hydrothermal vein-type deposit because of its sulfur isotopic properties, and the main sources of ore-forming fluid and minerals are thought to be buried intermediate-acid intrusions in the mining area’s depths.

Keywords

• cassiterite, trace element, deposit type, dalong tin deposit