Zuni Mountains

Zuni Mountain Crossection

The elevation of the Zuni Mountains is due to a major uplift of the geological strata called the Zuni uplift. This northwesterly trending anticline is deeply eroded, exposing the pre-Cambrian core. Cretaceous and older sedimentary strata once covered these mountains. The total elevation of the original Zuni uplift can be estimated from the thickness of the sedimentary rocks surrounding the current mountains, 4100 feet of Paleozoic rocks, 9500 feet of Mesozoic rocks, and 6600 feet of Cenozoic rocks -- 20200 feet total -- have been eroded from the summit of the Zuni Uplift, These mountains are still over 9000 feet at their highest point!

The remains of these layers are now seen in concentric rings around the mountains, with the harder layers rising out of the surface as tilted, sandstone capped ridges, and the softer layers forming valleys between these layers. The town of Ramah lies in one of these valleys, between a Cretaceous ridge to the south and a Jurassic ridge to the north. El Morro National Monument, where passing travellers for centuries have inscribed their names (more graffitti! this time enshrined as a National Monument) is also one of these eroded ridges.

If, like me, you are confused by the terms used to designate geologic time, a chart, based upon one given in Roadside Geology of Arizona by H. Chronic is available.

In Association with Amazon.com


Native Roads : The Complete Motoring Guide to the Navajo and Hopi Nations,
Fran Kosik, George Hardeen, Creative Solutions Pub.
A Guide Book to Highway 66, Jack D. Rittenhouse, Univ of New Mexico Press.
Basin and Range, John McPhee, Noonday Press.
Navajo Country : A Geology and Natural History of the Four Corners Region, Donald Baars, Univ. New Mexico Press.
The Colorado Plateau : A Geologic History, Donald L. Baars, Univ of New Mexico Press.
Roadside Geology of Arizona, Halka Chronic, Mountain Press.

In Association with Amazon.com

© 1994 Karen M. Strom
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