Figure A-19. Photomicrographs of thin sections and SEM photomicrograph from core samples from Trenton and Black River formations in Humble Riley No. 2, 26-3S-4W.

A. 4075 ft--Intercrystalline porosity (p) in a rock that has been completely dolomitized (Trenton). The original texture probably was wackestone to packstone. CN.

B. 4125 ft--Moldic and intercrystalline porosity (Trenton). Black specks are hydrocarbons. PPL.

C. 4216 ft--Wackestone with several well formed dolomite rhombs (Black River). Skeletal fragments include bryozoans and crinoids. PPL.

D. 4235 ft--SEM photomicrograph in backscatter electron mode (BSE) (Black River). A small vein in a dolomitized sample is lined with dolomite (D) and filled with anhydrite (A) and a small amount of fluorite (F). Minerals were identified using energy-dispersive analysis (EDA).

E. 4262 ft--Coarse crinoidal packstone, with fine stylolite seams (Black River). PPL.