SHERMAN MOUNTAINS
The Sherman Mountains are
erosional remnants rising above the general surface of the Laramie Range in
southeastern Wyoming. The Laramie Range (Laramie Uplift) is cored by
Precambrian igneous rock, most of which is a coarse-grained plutonic complex
called the Sherman Granite (early Mesoproterozoic, 1.4 billion years
old). Portions of the Laramie Range also have Mesoproterozoic
anorthosites.
The pic below shows
"Turtle Rock" in the Sherman Mountains. The Sherman Granite here has
three sets of joints. Differential erosion has resulted in distinctive,
somewhat rounded-weathering granite blocks.