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

<div>SEM images showing the typical habit and internal pore structure of organic matter in sample TRA-10. (a–f) Abundant graptolites and pyrite framboids distributed within the shale matrix. (a–c, e) Dispersed graptolite pieces without pores even enlarging current magnification. (f) A few pores of irregular and narrow shape inside graptolite grains, and the existence of such pores is not common in the studied sample.</div>

Geofluids

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Figure 12

Figure 12: Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S. 

Figure 12 | Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S. 