Geological characteristics of the Wuheng intrusion in Anqing, Anhui Province and its mineralization potential

The Anqing area located in the middle segment of the middle-lower Yangtze River polymetallic metallogenic belt is one of the critical regions for exploration of polymetallic deposits. In order to evaluate metallogenetic potential of the Wuheng intrusion, petrology, geochemistry and alteration characteristic of the Wuheng intrusion were studied and compared with that of the Yueshan intrusion. The results show that both the Wuheng and Yueshan intrusions in the Anqing area belong to intermediate-felisc rocks. The Wuheng intrusion is closely associated with gold and copper hydrothermal vein-type mineralization, while the Yueshan intrusion with copper, gold and other polymetallic mineralization. In addition, the Wuheng intrusion is lithologically characterized by transion from pyroxene diorite to monzodiorite, and the Yueshan intrusion consists mainly of diorite, monzodiorite and quartz diorite. Intensive hydrothermal alteration in the Wuheng intrusion shows obvious alteration zones. Among them the moderate-low temperature alteration zone is associated with mineralization of copper and gold in particularly, displaying significant potential of hydrothermal metallogenic system. The Yueshan intrusion shows relatively complete skarn-hydrothermal vein-type metallogenic system, which has potential to form large-scale copper and iron deposits. It is concluded in this study that the Wuheng and Yueshan intrusions are similar in terms of petrogenesis, tectonic setting, and hydrothermal system, and deep contact zones of the Wuheng intrusion with Triassic limestone might have potential for exploration of skarn-type mineralization.