Origin of dolomite in the third member of Feixianguan Formation (Lower Triassic) in the Jiannan area, Sichuan Basin, China

摘要

The third member of Feixianguan Formation, Jiannan area consists of marine carbonates, parts of which were dolomitized to form high-quality reservoirs. Based on petrographical features, three types of dolomite phases are distinguished, including very finely finely crystalline dolomite (type-D1), medium crystalline dolomite (type-D2), and coarse crystalline saddle dolomite (type-D3).