The massive Crystal Mountain Sandstone forms the backbone of the surrounding hills. A series of nearly flat-lying interbedded orthoquartzites and buff to gray banded shales of the Crystal Mountain SS are exposed in the Hwy 270 Roadcut.
Hydrothermal quartz veins in cavities and joints are common.
Small cross-laminations and graded bedding indicate the rocks are upright. These rocks appear to be near the center of an anticlinal flexure. Click for larger view. Hwy 270 Roadcut, Crystal Mountain Sandstone. Hydrothermal quartz veins fill fractures in sandstone talus.