Earth and Planetary Sciences ETDs


Otis M. McRae

Publication Date

Spring 4-11-1958


The northern part of the Ortiz Mountains of north-central New Mexico consists of a tilted fault block of Cretaceous Mancos shale and Mesaverde formation intruded by latite-andesite porphyry sills and laccoliths and a nepheline-bearing augite manzonite stock. Igneous activity started with the development of a volcanic vent in what is now the central part of the mountains. Volcanic debris from the vent want removed from the area by erosion and provided sedimentary material for the late [ ] Espinaso volcanics of the adjoining areas. Intrusion of the latite-andesite porphyry sills and laccolite followed extrusive igneous activity, as demonstrated by the fact that porphyritic rocks intrude the Espinaso volcanics in the adjacent areas. Igneous acitivity was concluded by the intrusion of the nepheline-bearing augite monzonite which cuts across the earlier rocks. Normal faulting along the eastern border of the adjoining Rio Grande depression uplifted the area in the late Pliocene or early Pleistocene time.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

J. Paul Fitzsimmons

Second Committee Member

Wolfgang Eugene Elston

Third Committee Member

Abraham Rosenzweig




Ortiz Mountains, New Mexico, Stratigraphy, Mesaverde formation, Galisteo formation

Document Type


mcrae_fig_1.tif (502056 kB)
Geologic Map and Structure Sections of the Northern Part of the Ortiz Mountains

McRae_geologic_map.tif (515637 kB)
Low Res Geologic Map and Structure Sections of the Northern Part of the Ortiz Mountains