Figure F5. Photomicrographs of clast types in gravel. A, B. Very fine quartz sandstone. C, D. Fine to medium quartzose sandstone. E, F. Medium lithic sandstone with common intermediate volcanic rock fragments and quartz grains (Sample 316-C0007D-12R-4, 21–26 cm). G, H. Medium to coarse lithic sandstone dominated by intermediate volcanic rock fragments (A–D, G, and H: Sample 316-C0007D-12R-CC, 51–55 cm). A, C, E, and G are under plane-polarized light and B, D, F, and H are under cross-polarized light.