Oligocene and early Miocene sedimentation in the southwestern Jemez Mountains and northwestern Albuquerque Basin, New Mexico
— Sean D. Connell, Daniel J. Koning, Shari A. Kelley, and Nathalie N. Brandes

Current geologic studies of the southwestern Jemez Mountains refine the stratigraphy of the Albuquerque basin of the Rio Grande rift. In the Rio Jemez drainage, between the towns of Gilman and Cañon, New Mexico, a previously unrecognized stratigraphic relationship between the Abiquiu Formation and the Zia Formation clarifies the tectonic history of the region. The Zia Formation overlies older rocks provisionally assigned to the Abiquiu Formation. Examination of drill-hole cuttings from the Tamara #1-Y well in the adjacent Albuquerque basin reveal a thick pre-Zia Formation stratigraphic succession assigned to the unit of Isleta well #2. This unit locally exceeds 2 km in thickness in other wells in the Albuquerque basin. The unit of Isleta well #2 is represented by a thin discontinuous lag of intermediate volcanic tuff ventifacts preserved on the footwall of the San Ysidro fault zone. Thickness variations within the unit of Isleta well #2 across documented geologic structures across a 5-15 km-wide area of the northwestern Albuquerque basin support the presence of a late Oligocene phase of faulting and erosion before deposition of the Zia Formation.