Abstract:

VMS deposits from thePaleo-Tethys stage are only exposed in the Sanjiang region of China. Whether this type of deposit exists in other parts of the Tethys or its metallogenic potential remains critical scientific and practical issues of interest. The Pamir region of Tajikistan, located between the Qinghai-Tibet Plateau and the Iranian Plateau, is an important component of the Tethys domain. The region remains underexplored due to limited geological work, a lack of systematic geological surveys and investments, and the absence of significant breakthroughs in mineral exploration to date. Geochemical surveys serve as an effective method for analyzing the distribution characteristics of metallic elements such as copper, lead, and zinc, while also enabling the rapid identification and prioritization of promising exploration areas and targets.

Based on the geochemical survey data at scales of 1∶1000000 and 1∶250000 jointly conducted by the China Geological Survey and the Tajikistan Geological Survey, this study focused on 1∶50000 geochemical surveys in anomalous areas and conducting anomaly verification, followed by anomaly verification and genetic analysis of the discovered mineralized bodies, while also exploring the regional mineralization potential. The research findings are as follows: (1) The primary anomalous element associations in the Tokhtamesh area of the Pamirs include Fe, Cu, Pb, Zn, Ag, Sb, Au, and As. The anomalies are large in scale, high in intensity, and show distinct zonation in concentration, with anomalies clearly controlled by strata and fault structures. Two prospective exploration target zones, labeled Z01 and Z02, were identified. These zones show potential for discovering massive sulfide copper-lead-zinc deposits and hydrothermal vein-type gold deposits. (2) Anomaly verification revealed six iron-copper polymetallic mineralization bodies, with three phases of mineralization identified. The first phase is the main mineralization period, forming VMS-type copper-lead-zinc mineralization bodies within Permian strata (Z01 target zone: Mineralization bodies I and II). The second phase is a hydrothermal reformation period involving deformation and metamorphism, forming bed-parallel and cross-layer vein-like iron-copper mineralization bodies (Mineralization bodies III, IV, V, and VI) and modifying the preexisting VMS-type copper-lead-zinc bodies. The third stage corresponds to the supergene oxidation period, during which weathering and erosion oxidized the previously formed mineralized bodies, resulting in zoning phenomena. It is inferred that the Z02 prospecting target area still holds potential for discovering VMS-type copper-lead-zinc deposits. (3) The Pamir-Tianshuihai area of Tajikistan-China demonstrate good metallogenic potential for VMS copper-lead-zinc deposits, with nine prospective exploration areas predicted. It is proposed that the Permian strata of the Paleo-Tethys stage within the Tethys region offer promising prospects for the exploration of VMS massive sulfide deposits, representing an important direction for future exploration efforts.

Key words: Paleo-Tethys, Iron-copper polymetallic mineralization, Geochemical survey, VMS type, Tajikistan