Deep structure and prospecting significance of the Cuonadong dome, Tethys Himalaya, China: Geophysical constraints

Abstract

The Cuonadong dome located at the eastern part of Tethyan Himalaya consists of three lithologic‐tectonic units from the inside to the outside: the lower, middle, and upper units. The large‐scale Cuonadong Be‐W‐Sn deposits are hosted in the strong shear zone of the middle unit of the dome. In this study, multi‐scale gravity and magnetotelluric data were used to generate two‐dimensional electrical resistivity models and three‐dimensional density models for the deep structure of the Cuonadong dome. The results show that interpretation of geophysical data on the deep structure is largely consistent with the three lithologic‐tectonic units in the dome. The lower unit consists of gneiss and leucogranites that are characterized by high electrical resistivity. Schist, skarn, and marble in the middle unit exhibit moderate electrical resistivity, and Be‐W‐Sn rare metal bodies are hosted in skarn and marble. The sedimentary rocks of the upper unit are characterized by low electrical resistivity. Therefore, we proposed a geophysical model that the deep leucogranites and the host rocks of the Be‐W‐Sn ore bodies can be well identified. Their morphologies and locations play a significant role for rare metal prospecting.