Sedimentary Facies of the Longmaxi Formation Shale Gas Reservoir in the Weiyuan Area Based on Elemental Characteristics

Figure 3

Sedimentary facies indicators of Well 8 and Well 1 in the Weiyuan area: (a) horizontal grain, silty carbonaceous shale; (b) horizontal grain, silty shale; (c) black carbonaceous shale; (d) graptolite in Microlayer ①; (e) graptolite in Microlayer ②; (f) graptolite in Microlayer ③; (g) siliceous spicule of Longmaxi Fm.; (h) siliceous spicule; (i) ostracod; (j) pyrite framboids in Microlayer ④; (k) pyrite framboids in Microlayer ③; (l) pyrite framboids in Microlayer ②.

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