Plate 2. Photomicrographs. 1. Gypsiferous chalk with sparse, whole foraminifers, Section 161-975B-34X-2, 7-11 cm. Apparent zoning is likely an artifact of sample preparation where the gypsum is altering to bassanite (CaSO₄ · H₂O; S. Hovorka, pers. comm., 1996). Scale bar is 0.1 mm. 2. Gypsiferous chalk with large euhedral to anhedral gypsum crystals that have undergone pressure solution where in contact with each other, producing stylolitic contacts. Section 975B-34X-2, 21-25 cm. Scale bar is 0.2 mm. 3. Finely laminated gypsum with thin submillimeter laminae of matrix that appear as dark, stylolitic seams. Dark spots along matrix seam are foraminifers. Scale bar is 0.1 mm. 4. Clastic interval containing fragments of lenticular gypsum within crenulated gypsum zone pictured in Figure 6. Section 975B-34X-CC, 15-19 cm. Scale bar is 0.2 mm. Click on image for enlargement.