Holocene Plant Remains from Rocky Arroyo and Last Chance Canyon, Eddy County, New Mexico

Abstract

Fossil packrat middens with well-preserved plant remains from Rocky Arroyo and Last Chance Canyon, Eddy Co., New Mexico, record a juniperoak community in the early Holocene (10,500 to 10,000 radiocarbon years ago). Midden samples also record relatively stable desert-grassland/desert-scrub communities with some juniper and oak for the last 4000 years. Grassland was probably present on the gentle divides between incised canyons at most times. The environments of the last 10,000 years in the summer monsoonal rainfall areas of southeastern New Mexico and Trans-Pecos Texas are not very well known, and many of the ideas that have been proposed are controversial. Ancient packrat (Neotoma) middens contain well-preserved plant materials that have mostly been used to reconstruct past vegetations and climates in the arid Southwest during the last Ice Age or late Wisconsin glacial age prior to about 11,000 years ago (Van Devender 1973, Wells 1966), and during the early Holocene (Van Devender 1977, Wells and Berger 1967). A few packrat middens of early and late Holocene ages have been reported from the northern Chihuahuan Desert in Texas and New Mexico (Van Devender and Everitt 1977, Van Devender and Riskind 1979, Van Devender and Wiseman 1977, Wells 1976). Here I report plant remains from early and late Holocene packrat middens from Rocky Arroyo (RA) and Last Chance Canyon (LC), Eddy Co., New Mexico. LOCATION AND VEGETATION. Packrat middens were collected from limestone rock shelters in Rocky Arroyo and Last Chance Canyon on the east flanks of the Guadalupe Mountains above the Pecos River Valley. The sites are west and southwest of Carlsbad, Eddy Co., New Mexico. Three samples were collected from two nearby sites in Rocky Arroyo at 1130 m (RA #1 and RA #2) and 1160 m (RA #3) elevation. RA #1 and #2 are from a cliff above the portion of Rocky Arroyo where the stream is permanent; RA #3 is from a dry side canyon. Burnet Cave with its archeological and faunal records (Howard 1935, Schultz and Howard 1935) is in Rocky Arroyo above the sites. Dry Cave with its rich late Wisconsinan vertebrate deposits is on Azotea Mesa above Rocky Arroyo (Harris 1970; Holman 1970; Van Devender, Moodie, and Harris 1976).