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Figure 3. Paleogeographic map of Feixianguan stage of the Early Triassic, with outcrop photo, core photos and photomicrographs of reservoirs in the Triassic Feixianguan Fm. The oolite shoals were widely developed on both platforms, and on the open platform there are many shoaling upward cycles. The discovered gas pools are small scale and belong to the limestone reservoirs with low porosity, while the more massive ooid limestone reservoirs with medium-sized gas pools were developed along marginal facies around the troughs. On the evaporite carbonate platform the countless shallowing-upward sedimentary cycles with sabkha sequences consisted of peloidal mudstone, oolitic grainstone, oolitic dolomite, anhydrite and dolomicsite. The discovered gas pools are the dolomite reservoirs with high porosity on the evaporite platform. The leeward marginal facies along the evaporite carbonate platform margin around Kaijiang-Liangping trough is a favorable belt with large and medium-sized reservoirs, up to 200-300 m thick.