In the granite areas of the Sierra Nevada are many hills and other summits having the form of domes. A few of the domes are symmetric, with approximately circular or oval bases, but the majority are somewhat one-sided or irregular. Associated with these domelike forms are closely related structures. The granite is divided into curved plates or sheets which wrap around the topographic forms. The removal of one discloses another, and the domes seem at the surface to be composed, like an onion, of enwrapping layers.
In explanation of these peculiar forms and structures two general theories have been advanced.* According to one theory the separation of the granite into curved plates is an original structure, antedating the sculpture of the country and determining the peculiarities of form. According to the other theory the structure originated subsequently to . . .