Identifying high potential gold mineralization using geological and stream sediment geochemical data: A case study from western Dangreyongcuo area in the central Lhasa terrane, Tibet, China

Abstract

Northern Tibet exhibits abundant placer gold deposits, with a longstanding history of mining activities. Despite the widespread placer gold occurrences, the reports on the primary rock gold deposits or occurrences remain scarce. The central Lhasa terrane in northern Tibet hosts well-developed Zenong Group volcanic rocks, indicating great potential for the exploration of porphyry-epithermal copper (gold) deposits. Here, we select the Dangreyongcuo area in this region to investigate its metallogenetic potentiality, through a comprehensive 1:50,000 stream sediment geochemical survey, analyzing 12 elements (Au, As, Sb, Ag, Te, Cu, Pb, Zn, W, Sn, Bi, and Mo), and a detailed geological mapping. We aim to identify gold-related mineralization anomalies and provide clues for further bedrock gold exploration in this region. Based on the stream sediment geochemical data, zones 1–4, have been delineated using single-element indicator Au and element association indicator Au + As + Sb, which was determined through robust principal component analysis (RPCA) and using the exploratory data analysis (EDA) method. Subsequent validation exercises evaluating these four delineated zones reveal that Zone 1, Xinlong-Langmeila area, is the most promising prospect due to its high element concentrations, large size, and marked coincidence of element assemblages (also referred to as high-large-coincidence anomalies; HLCAs) and its characteristics are in line with those of epithermal deposits. Notably, the Xinlong deposit represents the first documented epithermal gold deposit hosted within the Zenong Group volcanic rocks. The identification of this deposit offers valuable insights and strategic directions for the broader understanding of Zenong Group volcanic rocks across the central Lhasa terrane. Additionally, subsequent strategies have been proposed for mineral exploration at both Xinlong camp and regional scales.