First-day road log: From Santa Fe to Nambe, Cundiyo, Espanola, Abiquiu and Ghost Ranch
— Gary A. Smith, Paul W. Bauer, Lucas G. Spencer, Mark A. Gonzalez, Barker, James, M., Frank E. Kottlowski, George S. Austin, and David W. Love

Summary:

The first day of the field conference examines the stratigraphy and structure of the Española Basin and Abiquiu embayment parts of Rio Grande rift and border rocks of the Sangre de Cristo Mountains and Colorado Plateau. The trip begins by heading north from Santa Fe within the eastern Española Basin. Supplemental Log 2 leads to Nambe Falls and Nambe Lake where Proterozoic and Pennsylvanian rocks of the Sangre de Cristo Mountains are exposed adjacent to and beneath Miocene rift-basin fill.

Stop 1, south of the historic village of Chimayo, provides an overview of the boundaries of the Rio Grande rift and the rift filling Tesuque Formation. The route then skirts along the depositional contact between the Tesuque Formation and the Proterozoic rocks of the Sangre de Cristo Mountains near the village of Cundiyo. The trip then turns westward down the valley of the Rio Quemado and Santa Cruz River to Española. North of Española, in the village of Alcalde, participants will visit the Adobe Factory (Stop 2) and learn about the process of making New Mexico's most well known building material. The route returns to Española and then heads westward across the Rio Grande into the Abiquiu embayment along the Rio Chama. Stop 3 provides an overview of the Tertiary stratigraphy of the Abiquiu embayment, Quaternary evolution of the Rio Chama valley, and an opportunity to visit a pre-Columbian ruin. Farther west, at Stop 4, participants will examine the Abiquiu Formation, backdrop to many movie scenes and Georgia O' Keefe paintings, and also representing the distal sedimentary record of middle Tertiary volcanism in the San Juan Mountains and Latir volcanic fields.

Stop 5 is located at the well-exposed western margin of the Rio Grande rift, where the basin fill is faulted against flat-lying Permian and Mesozoic rocks of the Colorado Plateau. Unconformities between Jurassic and Eocene strata and between the Eocene strata and the Abiquiu Formation provide evidence for an earlier Laramide ancestry for the rift-bounding Canones fault zone and arguable evidence for Oligocene subsidence of the Abiquiu embayment. The field-trip route then continues westward onto the Colorado Plateau to Ghost Ranch, nestled amongst picturesque mesas of Triassic, Jurassic, and Cretaceous strata and home to New Mexico's state dinosaur, the small theropod Rioarribasaurus (nee Coelophysis). After a barbecue and tour of Ghost Ranch museum and dinosaur quarry, we return to Santa Fe.


Full-text (21.89 MB PDF)


Recommended Citation:

  1. Smith, Gary A.; Bauer, Paul W.; Spencer, Lucas G.; Gonzalez, Mark A.; Barker, James, M.; Kottlowski, Frank E.; Austin, George S.; Love, David W., 1995, First-day road log: From Santa Fe to Nambe, Cundiyo, Espanola, Abiquiu and Ghost Ranch, in: Geology of the Sante Fe Region, Bauer, Paul W.; Kues, Barry S.; Dunbar, Nelia W.; Karlstrom, K. E.; Harrison, Bruce, New Mexico Geological Society, Guidebook, 46th Field Conference, pp. 1-28. https://doi.org/10.56577/FFC-46.1

[see guidebook]