Deep background and process of mineralization of the Middle and Lower Reaches of Yangtze River Metallogenic Belt revealed by the geophysical structure

The Middle and Lower Reaches of Yangtze River Metallogenic Belt is an important treasure trove of Fe−Cu polymetallic resources in China. Previous research results have shown that the lithospheric tectonic evolution of the metallogenic belt is the key to understand the entire mineralization process and to predict new deposits. However, there is still great controversy over the tectonic control on deep setting and process of magma−mineral system, including two kinds of understanding: ① lithospheric extension and lower crust melting caused by upper mantle convection; ② stress regime conversion and deep magmatic activity related to the subduction of the ancient Pacific plate. Moreover, this important geological issue still lacks constraints from geophysical deep exploration data. Therefore, based on the geophysical exploration data obtained by the "Deep Mineral Resources Exploration and Evaluation Innovation Team" of the Science and Technology Innovation Team of the Ministry of Natural Resources in the metallogenic belt, we analyze the results and geology−geophysics models of multi depth scale from upper mantle to most upper crust. Then we summarize and supplement the relevant understanding of the deep setting and process of mineralization in the metallogenic belt. Moreover, we, here, propose that the mantle material upwelling caused by the detachment of intracontinental subduction slab beneath the metallogenic belt controled the deep material sources and channel elements of the mineral system in the study area. Therefore, Fe−Cu mineral system was controlled by the stress regime conversion caused by slab sinking, and was formed in a variable tectonic setting over time, although there was a unified deep structure.