Stratigraphy and Correlation of Triassic Strata Around the Nacimiento and Jemez Uplifts, Northern New Mexico
- ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
- Andrew B. Heckert Ph.D., Professor (Creator)
- Institution
- Appalachian State University (ASU )
- Web Site: https://library.appstate.edu/
Abstract: Triassic strata exposed along the flanks of the Nacimiento and Jemez uplifts (Sandoval County, northern
New Mexico) belong to the Middle Triassic Moenkopi Formation (Anton Chico Member) and the Upper
Triassic Chinle Group (Agua Zarca, Salitral, Poleo, and Petrified Forest Formations). The Moenkopi Formation
(strata previously assigned by most workers to the Permian Bernal Formation) is as much as 39 m thick and mostly
grayish red sandstone, siltstone, mudstone, and intraformational conglomerate. It disconformably overlies the
Permian Glorieta Sandstone and is disconformably overlain by the Agua Zarca Formation. The Agua Zarca is as
much as 61 m thick and mostly white to brown, trough-crossbedded, quartzose sandstone and siliceous conglomerate.
The overlying Salitral Formation is as much as 102 m thick and mostly purplish, smectitic mudstone. The
Poleo Formation disconformably overlies the Salitral and is as much as 41 m thick and mostly grayish yellow,
trough-crossbedded litharenite, subarkose and intrabasinal and siliceous conglomerate. Above the Poleo, the Petrified
Forest Formation is as much as 340 m thick and dominated by reddish brown, smectitic mudstone. South of
San Miguel Canyon (T19, R1W), the Poleo Formation essentially pinches out, though thin (<20m), lenticular
equivalents of the Poleo are locally present as far southeast as Vallecito Creek (T16N, R2E). Furthermore, throughout
Sandoval County, the lower portion of the mudstone-dominated interval above theAgua Zarca Formation, even
where the Poleo Formation is absent, is dominated by purplish mudstone characteristic of the Salitral Formation.
Therefore, to the south of San Miguel Canyon the Salitral and Poleo Formations can be recognized locally, but the
thick, mudstone-dominated section above the Agua Zarca is assigned to the Petrified Forest Formation. The Correo
Sandstone Bed crops out as a bench-forming sandstone up to 15 m thick at the top of the Petrified Forest Formation
along the southern flank of the Nacimiento uplift. Fossil vertebrates indicate the Petrified Forest Formation ranges
in age from Adamanian to Revueltian (latest Carnian-Norian) and support lithostratigraphic correlation of the
Triassic strata exposed in Sandoval County to nearby Triassic outcrops in the Chama basin, Lucero uplift, and
Hagan basin.
Stratigraphy and Correlation of Triassic Strata Around the Nacimiento and Jemez Uplifts, Northern New Mexico
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Additional Information
- Publication
- Lucas, S.G., and Heckert, A.B. (1996), Stratigraphy and correlation of Triassic strata around the Nacimiento and Jemez uplifts, northern New Mexico. New Mexico Geological Society Guidebook 47, p. 199-204. Archived in NCDOCKS with permission of the editor. Version of record available at: http://nmgs.nmt.edu/publications/guidebooks/47/
- Language: English
- Date: 1996