Cochise County sits in the Southeast corner of Arizona
adjacent to New Mexico
and Sonora, Mexico.
The San Bernardino Valley with its volcanic field is located in
corner of Cochise County.
The San Bernardino volcanic field actually
extends a short distance into Mexico.
Within the volcanic field
there are dozens
of eroded cinder cones, two maars, and obvious lava flows.
Due to the rapid
which basalt chemically weathers in this semi-humid environment there
of rust-colored volcanic
rocks. The youngest of the volcanoes is about
300,000 years old.
Some of the oldest features in the volcanic
field date back
about 5 million years.
photo credits: Google Earth, Digital Globe, INEGI