Earth and Planetary Sciences ETDs

Publication Date



In the Monte Largo Hills in the central part of north-central New Mexico, Precambrian metamorphic and igneous rocks, Paleozoic sediments, and Tertiary intrusive and extrusive igneous rocks occur. The metamorphics consist of a series of quartzo-feldspathic gneiss, mica schist, metaquartzite, and hornblende schists. These rocks were

derived from Precambrian sediments, mostly sandstones, arkoses and impure dolomites that were subjected to amphibolite facies synkinematic metamorphism. The Precambrian alkali granite appears to have been allochthonously emplaced with evidence near the contact of the quartzofeldspathic metamorphics for a parautochthonous formation. Quartz veins and pegmatite dikes of Precambrian age are also present. The sediments are conglomerate, sandstone, and limestone of the Pennsylvanian Sandia and Madera Formations. Porphyritic and nonporphyritic /dacite of Tertiary age also occurs.

The metamorphic rocks exhibit moderate to well developed foliation generally trending toward the northeast. The area is a northeast trending horst bounded on the west by the Tijeras fault and on the east by the Guiterrez fault. Two periods of faulting, one Precambrian and the other Tertiary, have affected the area, producing topographic saddles along the central ridge, offsetting the sedimentary beds, and bringing the Precambrian metamorphics and Pennsylvanian sediments into tectonic contact in the northeast. Most faults are high angle; a few exhibit minor drag folding.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Lee A. Woodward

Second Committee Member

Albert Masakiyo Kudo

Third Committee Member

J. Paul Fitzsimmons



Document Type


Included in

Geology Commons