Metallogenic response to geological structural evolution in Aguimiao area, Inner Mongolia

Abstract：Located in the western part of the Langshan orogenic belt, Aguimiao area is similar to the Dongshengmiao, Tanyaokou and Huogeqi large-superlarge Cu-Pb-Zn-Fe sulfide deposits in ore-forming structural geological setting and conditions. Based on an analysis of the geological setting of Langshan area and Aguimiao area, the authors studied the process of geological structural evolution and mineralization. Aguimiao area has experienced a long geological structural evolution and development process, which includes the following stages： ① the basement rock formation was formed in Neoarchean; ② the crystalline basement was formed, deformed and metamorphied in Upper Archean and Lower Proterozoic; ③ the passive continental margin aulacogen was broken up, received sediments and expereicned mineralization in Proterozoic; ④ the passive continental margin aulacogen was closed in late Neo-Proterozoic; ⑤ the development of compression and orogeny with considerable intrusion of acid-intermediate magma and the deformation occurred from Hercynian to Mesozoic. The different types of ore deposits were formed in different stages of geological structural evolution in Aguimiao area： ① the hydrothermal sedimentary banded-iron formation (BIF) deposits were formed in submarine volcanic environment in Neoarchean; ② the hydrothermal sedimentary sulfide deposits related to the Langshan passive continental margin aulacogenn were formed in Mesoproterozoic; ③ the middle-small sized porphyry copper-gold deposits were formed by the magmatic-hydrothermal activities，related to the process of compression and orogeny from Hercynian to Mesozoic.