Further Insights into Deep Structure of Malmyzh, Pony-Muli, and Anadzhakan Ore Clusters in the Middle Amur Sedimentary Basin (Northern Sikhote-Alin Orogenic Belt)

Abstract

Abstract —Magnetic and density depth models were calculated for the Malmyzh, Pony-Muli, and Anadzhakan porphyry-copper ore clusters emplaced in the northern part of the Middle Amur sedimentary basin. Based on analysis of anomalous magnetic field (magnetic model) data, a magmatogenic ring structure determining spatial patterns in localization of porphyry-copper mineralization in the Malmyzh and Pony-Muli ore clusters was established. It is shown that similar structures in the anomalous magnetic field are reported for many porphyry copper deposits. The area of the identified geologic structure can be considered as a high-potential region for detection of goldcopper-porphyry ore mineralization. Within the ring structure, perspective areas containing granitoid and diorite intrusions developed along its periphery and seated beneath the Middle Amur basin sedimentary cover can also be identified. Geophysical depth models are calculated for individual ore clusters with Au–Cu porphyry mineralization, to determine subsurface lithology and structures that may be useful for assessing regional ore potential and deducing areas for metallogenic exploration. The geophysical data-based deep subsurface model for the Malmyzh ore cluster is found to be consistent with the integrated petrological models developed by Richards and Sillitoe for giant Cuporphyry deposits.