Rootless mountains and gravity lows in the Sangre de Cristo Mountains, southern Colorado-northern New Mexico
L. Trevi??o, G. R. Keller, C. Andronicos, and O. Quezada
Gravity lows over large portions of the Sangre de Cristo Mountains are a geophysical curiosity in the southern Rocky Mountains. The Sangre de Cristo Mountains are largely composed of Proterozoic basement and Paleozoic sedimentary rocks. The exposure of uplifted, presumably dense, Proterozoic basement in the Sangre de Cristo Mountains should be associated with gravity highs, but this is not the case. In this study, we focused on two gravity lows in northern New Mexico-southern Colorado. One is centered over the Sangre de Cristo Mountains in Colorado and northernmost New Mexico, and the other is located near Mora, New Mexico. The northern low can be attributed to Precambrian rocks being thrust over less dense Paleozoic rocks resulting in a rootless basement. In the Mora area, the low is attributed to unusually low-density Precambrian granitic rocks (the 1.68 Ga Guadalupita pluton) underlying a thick sequence of Late Paleozoic and younger sedimentary rocks.
- Trevi??o, L.; Keller, G. R.; Andronicos, C.; Quezada, O., 2004, Rootless mountains and gravity lows in the Sangre de Cristo Mountains, southern Colorado-northern New Mexico, in: Geology of the Taos Region, Brister, Brian S.; Bauer, Paul W.; Read, AdamS.; Lueth, Virgil W., New Mexico Geological Society, Guidebook, 55th Field Conference, pp. 264-271.