Bulletin 62—Geology of Lordsburg Quadrangle, Hidalgo County, New Mexico

By R. F. Flege, 1959, 36 pp, 2 tables, 2 figs., 10 plates, 1 index.

Surface geologic mapping of Lordsburg quadrangle was accomplished during the summers of 1953 and 1954; laboratory work on the rock samples was performed at Washington University, St. Louis, in 1954 and 1955. The project was carried out in cooperation with the NM Bureau of Mines and Mineral resources.

The geology of the quadrangle was mapped on a scale of 1:48,000 and transferred to the excellent topographic sheet of Lordsburg quadrangle (scale 1:62,500). Aerial photographs, furnished by the State Bureau of Mines, provided full coverage of the quadrangle.

Lordsburg quadrangle lies in Hidalgo County in extreme southwestern NM. The length, which is 5 minutes greater than that of the standard 15-min quadrangle, was increased in order to include the whole of the Pyramid Mountains. The area thus enclosed covers approximately 333 mi².

Lordsburg, a town of about 4,000 population and the county seat of Hidalgo County, is the principal settlement within the quadrangle. Although numerous ranches are scattered throughout the area, the greatest part of the population is centered in Lordsburg. The town is supported mainly by the few operating mines in the Lordsburg mining district and by tourist business, farming, and cattle raising.

U.S. Highways 70 and 80 pass through Lordsburg, Highway 80 crossing the northern quarter of the quadrangle in an east-west direction, and Highway 70 entering Lordsburg from the east and then turning due north. A secondary gravel road, the Animas road, leads southward from Lordsburg, cuts north of the Leitendorf Hills, and thence runs due south along the western side of the Pyramid range. This road has been called the Old Animas Road since the construction of a new paved road to Animas a few miles to the west in the flat basin.

Although many of the unimproved farm and mine roads shown on the map are now unfit for travel because of washouts, most of the Pyramid range is reasonably accessible by automobile. The main line of the Southern Pacific Railroad passes through Lordsburg, traversing the northern part of the quadrangle in an east-west direction.