| Coronado National Memorial, administered
by the National Park Service, preserves 4,750 acres at the southern end
of the Huachuca Mountains in Cochise County, Arizona. The memorial is bordered
on the west and north by Coronado National Forest, on the east by state
and private lands, and on the south by Mexico.
The park is located on one of the
regions's metamorphic "sky island" mountain ranges of the Southwest's Basin
and Range Province. The Huachuca Mountains are traversed by numerous faults,
creating a rather chaotic and unusual geologic structure of interwoven
sedimentary and igneous rocks.
Localized metamorphism along the
many faults is common. Metamorphic rocks may also be seen along the contacts
between younger intrusive igneous bodies and older rock units. Localized
hydrothermal activity has also contributed to areas of mineralization and
metamorphism.
Marine fossil remains, ranging in
age from Pennsylvanian to Cretaceous, are present in the limestones, siltstones,
and sandstones, but are usually poorly preserved. Calcification, and replacement
by silica may both be found, but the former is far more common.
Landform
The highest elevation within Coronado is 7825
feet along the northern boundary. The land slopes, steeply at first, then
more gently, to the southeast corner, where the elevation is about 4825
feet. |
Qg
Quaternary sands and gravels - alluvial surface
deposits.
Kb
/ Kbu /Kbg Bisbee Group. Lower Cretaceous limestones,
arkose, sandstones and siltstones. Glance Conglomerate.
Jg
Jurassic Granite and Quartz. Coarse grained, sometimes
associated with mineralization.
Klvs
Lower Cretaceous rhyolitic volcanic rocks, conglomerates,
sandstone.
JTrvs
Jurassic and Triassic volcanic and sedimentary
rocks.
P[Pn
Naco Group. Permian and Pennsylvanian limestones
and Dolomites. 
