A Petrographic Study of the Three Forks Formation (Upper Devonian), Williston Basin, North Dakota: Based on Thin Section Analysis, XRD and SEM

Figure 4

Photomicrographs of lithofacies 3. (a) x50ppl, ferroan (F Dol), nonferroan dolomites, associated minerals, and matrix partings (c+org); (b) x100ppl, anhedral (Dol 1) to subhedral (Dol 2) dolomite; (c) x200ppl, unloading fracture (Unl frac), associated minerals, and intercrystalline pores (Ixl); (d) x400ppl, clearly showing the 1st (Dol 1), 2nd (Dol 2), and 3rd (Dol 3) generation dolomites that occlude the intercrystalline pores and limit the interconnectivity.

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