Dos Cabezas Mountains -Geology
Dos Cabezas Mountains -GeologyRoger Weller, geology instructor
wellerr@cochise.edu last edited: 10/9/07
Sixty percent of the Dos Cabezas range is a complex exposure of metamorphosed Precambrian sedimentary rocks and igneous intrusions. These Precambrian rocks (1 to 1.2 billion years old) are overlain by Paleozoic and Mesozoic sediments. During the Laramide orogeny (150 to 50 million years ago) the Dos Cabezas range was broken by faulting.
The rocks of these mountains record a history of four intense metamorphic and
intrusive periods. The first event was the metamorphism that resulted in the
formation of the Precambrian Pinal Schist, approximately 1700 million years
ago. The second major event was characterized by intense plutonism and
tectonism between 1450 and 1375 million years ago. The area was intruded two
more times by volcanic rocks that were dated to be 75 to 50 million years ago
and 35 to 29 million years ago.
Maps of the Dos Cabezas Mountains
Published references on the Dos Cabezas Mountains