Mesozoic Paleo-Pacific plate subduction effect revealed by 3-D magnetotelluric imaging in the southeastern Great Xing’an Range, Northeast China

The Great Xing’an Range is situated along the eastern margin of the Central Asian Orogenic Belt, which is a key area in Northeast China for studying geological evolution and polymetallic mineralization. From 2009 to 2023, magnetotelluric (MT) array data were collected in the southeastern Great Xing’an Range. Data processing, phase tensor analysis, and 3-D inversion calculation were used to obtain a preferred 3-D electrical conductivity model. The results revealed several zones of high-conductivity anomalies with a north-south distribution from the upper mantle to the mid−lower crust, which reflect a lithospheric extensional structure that is possibly related to the regional mantle flow triggered by the Mesozoic subduction of the Paleo-Pacific slab. The formation of Mesozoic magmatic hydrothermal deposits in the study area was associated with the upwelling of asthenospheric material. The north-south electrical anomaly plays an important role in controlling mineralization and may be a target for future resource exploration.