Tectonic evolution, differential deformation and gas exploration prospect of Hefei basin

Abstract：The Hefei basin experienced evolutionary stages of basement formation, depression, rifting and tectonic inversion, and five structural stages have been further recognized as follows： development stage of J1-J2 depression basin, development stage of J3 foreland basin, development stage of K1 strike slip basin, development stage of K2-E rifted basin, and consuming stage of N-Q basin. The key tectonic changes controlling the tectono-stratigraphic framework of Hefei basin are Early Yanshanian, Central Yanshanian, Late Yanshanian and Early Himalayan movements. The structures in the study area are characterized by differential deformation. Three tectonic belts can be recognized, namely, Jinzhai-Shucheng, Liuan-Feixi, and Huainan-Dingyuan. The structural zoning was controlled by a series of NWW-trending fault zones and experienced four periods of tectonic deformation, i.e., Early Yanshanian, Central Yanshanian, Late Yanshanian and Early Himalayan. A preliminary analysis of the exploration potential of the structural deformation zone reveals that Huainan-Dingyuan tectonic belt is the first-grade prospective area, i.e., the most favorable structural deformation zone; Luan-Feixi belt is the second-grade prospective area, i.e., an area beneficial to tectonic deformation; Jinzhai-Shucheng is of the third grade, i.e., an relatively favorable structural deformation zone.