Three-dimensional magnetotelluric imaging of the Eastern Qinhang Belt between the Yangtze Block and Cathaysia Block: Implications for lithospheric architecture and associated metallogenesis

Abstract

The Eastern Qinhang Belt represents the suture zone between the Yangtze and Cathaysia Blocks and controls the world-class Dexing porphyry copper (Cu) deposits. A three-dimensional three-dimensional structural interpretation based on magnetotelluric array data covering the Eastern Qinhang Belt was determined to provide new information on the lithospheric architecture of this mineral system. The regional electrical structure of the Eastern Qinhang Belt is consistent with the pattern of the Appalachian-style multi-terrane Wilson cycle, with the main electrical gradients corresponding to pre-existing lithospheric faults. It is possible that the central domain between the Huaiyu Terrane and Western Cathaysia Block preserved the slivers of the mafic lower crust generated by the modification of Neoproterozoic subduction. Partial melting of this juvenile mafic lower crust was triggered by the extension from the rollback of the Paleo-Pacific Plate during the Mid-Jurassic. The Northeast Jiangxi Fault represents the conduit for the rise of ore-bearing magmas capable of producing porphyry Cu mineralization.