REYNOLDS, CHARLES B., Geological Associates, Albuquerque, NM

ABSTRACT: South Margin of the Cuervo Trough, Tucumcari Basin, New Mexico

One of the deeper parts of the Tucumcari Basin of east-central New Mexico is what has been called the Cuervo sub-basin, within which the deepest well to date is the General Crude No. 1 Simpson, Sec. 21 T10N R23E. This well reached Precambrian basement at a depth of 9,060 ft (-4,396 ft SSL). The Cuervo sub-basin has generally been shown in published literature as a small feature centered in T10N R23E and terminated westward by an arcuate, southward-moving thrust block or sheet. Gravity and magnetic data, however, are interpreted to suggest that the sub-basin emerges from beneath the other side of the thrust sheet to continue to the west-southwest for a total original subbasin length of about 75 miles. This sub-basin is interpreted as becoming shallower westward and culminating in a saddle between the Pedernal uplift to the south and the Sierra Grande uplift to the north. Because of its length, a more descriptive name for this Pennsylvanian and Permian age feature might be the Cuervo trough. The south margin 9 of this trough is the boundary between the clastic-dominated trough to the north and the carbonate-dominated shelf to the south, and may be a major locus for hydrocarbon accumulations in granite wash pinchouts, reefs, and anticlinal structures.

AAPG Search and Discovery Article #90915©2000 AAPG Rocky Mountain Section, Albuquerque, New Mexico