Correlation of Jurassic strata from the Colorado Plateau to the High Plains, across the Rio Grande rift, north-central New Mexico
Spencer G. Lucas, John W. Estep, and Orin J. Anderson
Subsurface and outcrop sections of Jurassic strata in the Rio Grande rift of north-central New Mexico provide the basis for correlation of the Jurassic strata of the Colorado Plateau and the southern High Plains. This correlation indicates continuity of the Entrada, Todilto, Summerville, and Morrison formations across the Rio Grande rift. However, between the Jurassic section at Galisteo Darn in the rift (described here for the first time) and Romeroville section on the edge of the southern High Plains, the eastward pinchout of the following units takes place: Dewey Bridge Member of Entrada Sandstone, Tongue Arroyo Member of Todilto Formation, and Jackpile Member of Morrison Formation. Continuity of the J-2, J-3, and J-5 unconformities across the Rio Grande rift is indicated, and there is a probable regional unconformity at the Todilto-Summerville contact that may correlate to the J-4 unconformity. Jurassic depositional systems were continuous from the Colorado Plateau to the southern High Plains, so it is necessary to interpret these systems based on data gathered from both areas.
- Lucas, Spencer G.; Estep, John W.; Anderson, Orin J., 1999, Correlation of Jurassic strata from the Colorado Plateau to the High Plains, across the Rio Grande rift, north-central New Mexico, in: Albuquerque Country, Pazzaglia, Frank J.; Lucas, S. G.; Austin, G. S., New Mexico Geological Society, Guidebook, 50th Field Conference, pp. 317-326.