Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S.

<div>Organic petrography photomicrographs (oil immersion, white incident light) showing typical types and morphology of organic matter in Wufeng-Longmaxi shale samples. (a, b) Graptolite fragment with biological shape and fibrous structure within its cell wall. (c) Chitinozoan fragment with a segment or scalene shape. (d) Pyrobitumen of ~40 micrometers in size filling the shale matrix.</div>

Geofluids

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Figure 5

Figure 5: Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S. 

Figure 5 | Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S. 