Shoshonite

What the map says

Dark-gray porphyritic lava flows capping North and South Table Mountains and forming dikes near Ralston Reservoir (also includes Flagstaff Mountain sill near Boulder, dated at 64 m.y. by Hoblitt and Larson, 1975). Includes Table Mountain Shoshonite (Scott, 1972) and monzonite and latite of Van Horn (1972). Three flows recognized in North Table Mountain and two flows recognized in South Table Mountain. Total thickness of flows about 73 m. Age of middle flow probably is 63-64 m.y. (Scott, 1972) and age of Ralston Reservoir intrusive is 62 m.y. (Hoblitt and Larson, 1975).

1:100,000 sheet: Trimble and others, 2003, U.S. Geological Survey Geologic Investigations Series I-856-H (17 crags). A contact line at that scale is about 100 m wide on the ground.

Served by Macrostrat (CC BY 4.0). The wording is the map's own, quoted as a fact about the mapped unit, not about any one wall.