Structural and stratigraphic evidence for the Laramide (early Tertiary) Burro uplift in southwestern New Mexico
Greg H. Mack and Russell E. Clemons
The late Laramide (Paleocene-Eocene) Burro uplift in the vicinity of the Florida Mountains and southern Cooke's Range, southwestern New Mexico, was a west—northwest-trending, basement-cored uplift that consisted of at least three major segments. The southern segment was uplifted by the southward-dipping, high-angle, right-lateral oblique-slip south Florida Mountains reverse fault that brought Precambrian-Cambrian crystalline basement over Paleozoic sedimentary rocks. Three levels of imbricate thrusts within Paleozoic sedimentary rocks rooted into and were the result of movement on the south Florida Mountains fault. The southern segment was bordered on the north by a closed, intra-uplift basin that was floored by less than 200 m of locally derived alluvial-fan and lacustrine detritus of the Lobo Formation. The Lobo Formation thins northward and pinches out against the basement-cored northern portion of the central segment. The northern segment consisted of a complementary basin that contained at least 350 m of the Lobo Formation. Deposition in the northern basin was by alluvial-fan and fluvial processes. The presence of basement-cored blocks separated by largely undeformed basins and evidence of only a few kilometers of crustal shortening suggest that the tectonic style of the Laramide Burro uplift is more analogous to the Laramide Rocky Mountain foreland than to the Sevier overthrust belt.
- Mack, Greg H.; Clemons, Russell E., 1988, Structural and stratigraphic evidence for the Laramide (early Tertiary) Burro uplift in southwestern New Mexico, in: Cretaceous and Laramide tectonic evolution of southwestern New Mexico, Mack, G. H.; Lawton, T. F.; Lucas, S. G., New Mexico Geological Society, Guidebook, 39th Field Conference, pp. 59-66.