Pancho Villa State Park

modified from McLemore, V.T., 2000, Pancho Villa State Park: New Mexico Geology, v. 22, no. 1, p. 18-22.

Introduction

Pancho Villa State Park in Columbus, New Mexico, (Fig. 1) was established in 1959 “in interest of preservation of the memory of the unique, historical occasion of the last hostile action by foreign troops within the continental United States” (Kottlowski, 1980). It became the only park in the United States to be named after a foreign invader. The creation of the 60-acre park was a gesture of good will between the United States and Mexico. The town of Columbus has been designated a National Historic Site. Across the street from the park is the privately owned Pancho Villa Museum.

Geology

Pancho Villa State Park lies on the nearly flat alluvial plain extending southward from the Tres Hermanas Mountains (Spanish for three sisters). The alluvial plain consists of gravel, sand, and mud derived from the adjacent mountains and transported by streams and sheetwash. The Mimbres River, which starts in the Pinos Altos Mountains to the north, flowed episodically throughout the Pleistocene and Holocene past Deming, around the Florida Mountains, east of Columbus, and into Mexico to fill the playa lakes south of Las Palomas in the Bolson de los Muertos (Kottlowski, 1980; Love and Seager, 1996). Today, the Mimbres River flows into the Mimbres Basin east of Deming. Ground water in the buried alluvial fan deposits, in part a remnant of the ancient Mimbres River, is pumped to irrigate fields in the Deming and Columbus areas.

The most prominent land feature within the park is Villa Hill (also known as Coote’s Hill), in the northwest corner. This hill rises approximately 25 ft above the flat, featureless desert floor and is composed of reddish-brown to black, vesicular basalt. Gas bubbles formed the vesicles or irregular cavities during cooling of the basaltic lava as it flowed from its vent, now covered by the lava. Small xenoliths or fragments of limestone and other country rock are found within the basalt. A sample of the basalt was dated by the ⁴⁰Ar/³⁹Ar dating technique and was determined to be 3.8 million years (m.y.) old (unpublished age determination, New Mexico Geochronology Research Laboratory, New Mexico Institute of Mining and Technology). A sample of a similar lava flow southwest of Columbus has been dated as 3 m.y. old (Seager et al., 1984). Geochemically, the Pancho Villa basalt is alkaline and similar in chemical composition to the basalts found in the Potrillo volcanic field south of Las Cruces and east of Columbus. The basalt was formed by partial melting of material derived from the upper mantle (Anthony et al., 1992) and was extruded during the latest stages of the formation of the Rio Grande rift (Seager et al., 1984; McLemore, 1999). A rift is a long, narrow feature where the Earth’s crust is being pulled apart by plate tectonic forces (Fig. 2). As the crust is pulled apart, large blocks in the center of the rift drop into the resulting elongate depression or trough, known as a graben. The Rio Grande rift is actually a series of linked troughs extending from near Alamosa, Colorado, southward to El Paso, Texas. The Mimbres Basin east of Deming is one of these down-dropped troughs. The remainder of the state park consists of relatively flat, sandy desert soil; small sand dunes are common throughout the park.

The Tres Hermanas Mountains are three prominent peaks 7 miles northwest of the park. The three peaks consist predominantly of a quartz-monzonite stock that is about 35 m.y. old (unpublished age determination, New Mexico Geochronology Research Laboratory, New Mexico Institute of Mining and Technology). The quartz monzonite is surrounded by a thick sequence of predominantly Paleozoic and Cretaceous sedimentary rocks and Tertiary volcanic rocks (Balk, 1962; Griswold, 1961; Leonard, 1982). Fragments of monzonite, rhyolite, latite, basalt, andesite, chert, and limestone, some as large as 1–2 ft in length, were transported by occasional stream flows from the Tres Hermanas Mountains to the park where they may be seen scattered among the cacti. Gold, silver, copper, lead, and zinc were discovered in the Tres Hermanas Mountains in about 1881. Total production from the mineral deposits in the district is unknown but is estimated from 1885 to 1957 as $600,000 worth of copper, gold, silver, lead, and zinc, including 200,000 lbs of lead and 1 million lbs of zinc (McLemore et al., 1996).

The Florida Mountains form the jagged peaks north to northeast of Columbus. The range consists of Paleozoic through lower Tertiary sedimentary and volcanic rocks overlying Proterozoic and Cambrian granite and syenite plutons (Clemons and Brown, 1983; Clemons, 1984). Tertiary rhyolite, diorite, and andesite intrude the older rocks. From 1880 to 1956, 5,000 lbs copper, <10 oz gold, 8,000 oz silver, and >30,000 lbs lead worth approximately $102,000 were produced from carbonate-hosted lead–zinc replacement and polymetallic vein deposits in the Florida Mountains mining district. In addition, 200 short tons of fluorite and 1,421 long tons of 22–30% manganese have been produced from epithermal veins.

The sharp, jagged peaks of the Big Hatchet Mountains lie on the western skyline. The Big Hatchet Mountains consist of faulted and tilted Paleozoic limestones and Cretaceous shales and sandstones that show few signs of mineralization or alteration (Zeller, 1975; Drewes et al., 1988; Drewes, 1991a, b). The rocks in the area consist predominantly of Horquilla Limestone and Earp Formation, with a thin, thrusted band of Oligocene andesite or basaltic andesite. Small carbonate-hosted lead–zinc replacement deposits have been identified along the faults; production from these deposits has been small, amounting to less than $2,000 (McLemore et al., 1996).

References

1. Anthony, E. Y., Hoffer, J. M., Waggoner, W. K., and Chien, W., 1992, Compositional diversity in late Cenozoic mafic lavas in the Rio Grande rift and Basin and Range province, southern New Mexico: Geological Society of America, Bulletin, v. 104, pp. 973–979.
2. Balk, R., 1962, Geologic map of Tres Hermanas Mountains, Luna County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Geologic Map 16, scale 1:48,000.
3. Clemons, R. E., 1984, Geology of Capitol Dome quadrangle, Luna County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Geologic Map 56, scale 1:24,000.
4. Clemons, R. E., and Brown, G.A., 1983, Geology of Gym Peak quadrangle, LunaCounty, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Geologic Map 58, scale 1:24,000.
5. Clemons, R. E., Christiansen, P. W., and James, H. L., 1980, Southwestern New Mexico: New Mexico Bureau of Mines and Mineral Resources, Scenic Trips to the Geologic Past, no. 10, 119 pp.
6. Drewes, H., 1991a, Geologic map of the Big Hatchet Mountains, Hidalgo County, New Mexico: U.S. Geological Survey, Miscellaneous Investigations Series, Map I–2144, scale 1:24,000.
7. Drewes, H., 1991b, Description and development of the Cordilleran orogenic belt in the southwestern United States: U.S. Geological Survey, Professional Paper P–1512, 92 pp.
8. Drewes, H., Barton, H. N., Hanna, W. F., and Scott, D. C., 1988, Mineral resources of the Big Hatchet Mountains Wilderness Study Area, Hidalgo County, New Mexico: U.S. Geological Survey, Bulletin 1735–C, pp. C1–C22.
9. Griswold, G. B., 1961, Mineral deposits of Luna County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Bulletin 72, 157 pp.
10. Kottlowski, F. E., 1980, Pancho Villa: New Mexico Geology, v. 2, no. 3, pp. 45–46.
11. Leonard, M. L., 1982, The geology of the Tres Hermanas Mountains, Luna County, New Mexico: Unpublished MS thesis, University of Texas (El Paso), 105 pp.
12. Love, D. W., and Seager, W. R., 1996, Fluvial fans and related basin deposits of the Mimbres drainage: New Mexico Geology, v. 18, no. 4, pp. 81–92.
13. McLemore, V. T., 1999, Leasburg Dam State Park and Fort Selden State Monument: New Mexico Geology, v. 21, no. 3, pp. 66–70.
14. McLemore, V. T., Sutphin, D. M., Hack, D. R., and Pease, T. C., 1996, Mining history and mineral resources of the Mimbres Resource Area, Doña Ana, Luna, Hidalgo, and Grant Counties, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Open-file Report 424, 251 pp.
15. Seager, W. R., Shafiqullah, M., Hawley, J. W., and Marvin, R. F., 1984, New K–Ar dates from basalts and the evolution of the southern Rio Grande rift: Geological Society of America, Bulletin, v. 95, pp. 87–99.
16. Young, J. V., 1984, The state parks of New Mexico: University of New Mexico Press, Albuquerque, 160 pp.
17. Zeller, R. A., Jr., 1975, Structural geology of Big Hatchet Peak quadrangle, Hidalgo County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Circular 146, 23 pp.