New Mexico Bureau of Mines & Mineral Resources Bulletin 117 Geology of Carlsbad Cavern and other caves in the Guadalupe Mountains, New Mexico and Texas

Location and physiography

The study area encompasses the Guadalupe Mountains of southeastern New Mexico and western Texas (Fig. 1), a region of sharp limestone ridges and steep-walled escarpments. The Guadalupe Mountains are a wedge-shaped block bounded on the west by a fault-line escarpment and on the east by an exhumed-reef escarpment and the Gypsum Plain (Figs. 2, 3). The area is bounded by the McKittrick Hill anticline on the northeast, Guadalupe Peak on the southwest, the Capitan reef escarpment on the southeast, and the Dark Canyon drainage on the northwest. The highest elevation in the area is Guadalupe Peak at 2,667 m; the lowest point is Wind (Hicks) Cave at 1,115 m. The area forms a narrow band 6.4-9.6 km wide and 80 km long through Eddy County, New Mexico, and Culberson County, Texas.

FIGURE 1—Location of the study area. After Jagnow (1979).

FIGURE 2—Landsat image of the triangular, wedge-shaped Guadalupe Mountains area. (click on image for a PDF version)

FIGURE 3—The Guadalupe Mountains and Gypsum Plain near Carlsbad, New Mexico. The Capitan reef escarpment rises along the edge of what once was the Delaware Basin. The headquarters of Carlsbad Caverns National Park sits atop the remains of the reef. Guadalupe Peak can be seen at the extreme upper left, Slaughter Canyon is in middle distance, and Walnut Canyon is a snakelike feature on the right. Photo Jeep Hardinge.

The region is dominated by thick limestone reef deposits and surrounding related rock within which extensive caves have developed. Cave locations are within Carlsbad Caverns and Guadalupe Mountains National Parks, and on lands controlled by Lincoln National Forest and the Bureau of Land Management. The highest cave, Cottonwood, is at an altitude of 2,074 m, and the lowest known cave passage, the Lake of the Clouds, Carlsbad Cavern, is at 1,007 m.

Two notable drainage systems exist in the area: a northeast-southwest drainage system which includes North and South McKittrick Canyons, Cottonwood Canyon, Dark Canyon, West Slaughter Canyon, North and South Rattlesnake Canyons, and Walnut Canyon; and a northwest-southeast drainage system which includes Big Canyon, Black Canyon, Gunsight Canyon, Double Canyon, Lechuguilla Canyon, and Slaughter Canyon (Fig. 5). The drainage systems have downcut the Guadalupe Mountains into a series of northeast- and northwest-trending ridges.

Climate

The climate in the Guadalupe Mountains is semiarid and continental, with characteristically mild winters and warm summers. The average winter temperature is 7°C and the average summer temperature is 27°C. Precipitation aver ages 35.6 cm annually, with 80% of the rainfall occurring in the May through October period (Houghton, 1967). Vegetation includes cactus, succulents, and desert shrubs in the lower Guadalupe Mountains, with transitional to montane coniferous forest on the upper Guadalupe ridges.

Past climate in the Guadalupe Mountains was more moist and cool than it is today. During much of the Pleistocene, coniferous forests reached to lower elevations and animal life included bear, American lion and cheetah, ground sloth, shrew, tapir, bison, bighorn sheep, camel, and llama (Harris, 1985).