Figure 22D. Thin-section photomicrograph of sidewall core sample from Eugene Island Block 330 (Plane polarized light: scale = 0.25 mm.) Fine-grained sandstone (subarkose). C, chert; F, plagioclase feldspar; P, pelecypod fragment; Q, quartz. LF sandstone. E.I. 330 #B-2, 8338 ft.