Eolian stratigraphy of intrabasinal fault depressions in the northern Hueco and southern Tularosa Basins: Evidence for neotectonic activity
Brenda J. Buck, John M. Jr. Kipp, and H. Curtis Monger
North-south-trending depressions, which parallel the major boundary faults between the northern Hueco and southern Tularosa Basins and the Franklin, Organ, and San Andres Mountains, have been interpreted as small intrabasinal normal faults (Seager, 1980, Seager et al., 1987; Machette, 1987; Collins and Raney, 1990, 1991a, b, 1994). However, because these areas lie within the Fort Bliss Military Reservation and White Sands Missile Range, little work has been done on them. This project excavated and described approximately 140 profiles, including 81 within eight intrabasinal fault complexes as part of an archaeological study to determine the late Quaternary stratigraphy within the basin. Our results show five major stratigraphic units within the Hueco Basin: La Mesa, eolian analogs of the Jornada (I and II), Isaacks' Ranch, and Organ deposits, and lastly, the Historic Blowsand deposit. These sediments contain the same morphologic features and have similar radiocarbon ages as sediments along adjacent alluvial fans, indicating that these eolian sediments are time correlative to the extensively-studied deposits along the alluvial fans in the adjacent Desert Project (Buck, 1996; Buck et al., 1997; Buck and Monger, in press). Morphologic features, isotopic and pollen studies, as well as radiocarbon dates, suggest that the stratigraphy of both types of sediments are controlled by alternating periods of erosion and deposition, which are primarily driven by climatic fluctuations. However, stratigraphic differences along intrabasinal faults suggest some additional local tectonic controls. Understanding the late Quaternary stratigraphy within these basins is crucial for future neotectonic studies. Evidence for seismic activity possibly as recently as the late Pleistocene or early Holocene was found in the form of seismic-induced liquefaction features and fault-related offset of units.
- Buck, Brenda J.; Kipp, John M. Jr.; Monger, H. Curtis, 1998, Eolian stratigraphy of intrabasinal fault depressions in the northern Hueco and southern Tularosa Basins: Evidence for neotectonic activity, in: Las Cruces Country II, Mack, G. H.; Austin, G. S.; Barker, J. M., New Mexico Geological Society, Guidebook, 49th Field Conference, pp. 79-86.