Constraining the depositional age of the Gatuña Formation

The Gatuña Formation was named by Lang (in Robinson and Lang, 1938) for alluvial deposits of mixed lithology dominated by red sand exposed in Gatuña Canyon in the lower Pecos River Valley of southeastern New Mexico (see map). Lang indicated that the formation is Quaternary in age, accumulating in “post High Plains time". Usage of the Gatuña Formation name and stratigraphic concept has been informally broadened to include deposits thought to be as old as the Ogallala Formation, extending northward to Guadalupe County, New Mexico and southward and eastward to include Pecos Valley fills in Texas (see discussion in Powers and Holt, 1993). The depsotional age of the Gatuña Formation is poorly constrained, with proposed estimates that vary from as old as Miocene at its base to as young latest Pleistocene at its highest levels (Hawley, 1993; Powers and Holt, 1993; Hall and Goble, 2012). The main reliable intraformational age constraint is the presence of the ca. 0.6 Ma Lava Creek B ash within Gatuña Formation strata along Livingston Ridge on the southern side of Nash Draw (Bachman, 1980; Izett and Wilcox, 1992). Previous workers have proposed division of the Gatuña Formation into diachronous upper and lower parts, which Attia and Allen (2022) found no supporting evidence for during new detailed geologic mapping in the Pierce Canyon area.

To better bracket the depositional age of the Gatuña Formation and its context within the late Cenozoic landscape, we collected one sample from an outcrop along Livingston Ridge for detrital sanidine Ar-Ar geochronology (more information on method in Heizler et al., 2021) and detrital zircon U-Pb geochronology analyses and several samples from the Pierce Canyon area for additional detrital age analyses. These data will provide maximum depositional ages for parts of the formation and provide additional information about the detrital provenance of the mineral grains found within Gatuña sands. This collaboration, between NMBGMR personnel at both the New Mexico Geochronology Research Laboratory (Ricci and Heizler) and the Geologic Mapping Program (Attia and Allen), represents an exciting opportunity to generate multiple detrital geochronology datasets from the same samples.

For more information, contact:
Dr. Snir Attia— Field Geologist

Results

1. Attia, S., Heizler, M.T., and Ricci, J., 2023, Quaternary age of the Gatuña Formation at Livingston Ridge, in Land, L., Bou Jaoude, I., Hutchinson, P., Zeigler, K., Jakle, A., Van Der Werfff, B., eds., Evaporite Karst of the Lower Pecos Region: New Mexico Geological Society 73^rd Annual Fall Field Conference Guidebook, 103-111.

References

1. Attia, S., and Allen, B.D., in preparation, Geologic map of the Pierce Canyon 7.5’ quadrangle, Eddy County, New Mexico: New Mexico Bureau of Geology Open-file Geologic Map, scale 1:24,000.
2. Bachman, G.O., 1980, Regional geology and Cenozoic history of Pecos region, southeastern New Mexico: U.S. Geological Survey, Open-File Report 80-1099, 116 p.
3. Hall, S.A., and Goble, R.J., 2012, Berino paleosol, late Pleistocene argillic soil development on the Mescalero sand sheet in New Mexico: The Journal of Geology, v. 120, p. 333-345.
4. Hawley, J.W., 1993, The Ogallala and Gatuña Formations in the southeastern New Mexico region: A progress report, in Love, D.W., Hawley, J.W., Kues, B.S., Austin, G.S., and Lucas, S.G., eds., Carlsbad Region (New Mexico and west Texas): New Mexico Geological Society, Fall Field Conference Guidebook 44, p. 261-269.
5. Heizler, M.T., Karlstrom, K.E., Albonico, M., Herefor, R., Beard, L.S., Cather, S.M., Crossey, L.J., and Sundeel, K.E., 2021, Detrital sanidine ⁴⁰Ar/³⁹Ar dating confirms <2 Ma age of Crooked Ridge paleoriver and subsequent deep denudation of the southwestern Colorado Plateau: Geosphere, v. 17, n. 2, p. 438-454.
6. Izett, G.A. and Wilcox, R.E., 1982, Map showing localities and inferred distributions of the Huckleberry Ridge, Mesa Falls and Lava Creek Ash Beds (Pearlette family ash beds) of Pliocene and Pleistocene age in the western United States and southern Canada: U.S. Geological Survey, Miscellaneous Investigations Map 1-1325, scale 1:4,000,000.
7. Powers, D.W., and Holt, R.M., 1993, The upper Cenozoic Gatuña Formation of southeastern New Mexico, in Love, D. W., Hawley, J. W., Kues, B. S., Austin, G. S., and Lucas, S. G., eds., Carlsbad Region (New Mexico and West Texas): New Mexico Geological Society, Fall Field Conference Guidebook 44, p. 271-282.
8. Robinson, R.W., and Lang, W.B., 1938, Geology and ground-water conditions of the Pecos River valley in the vicinity of Laguna Grande de la Sal, New Mexico, with special reference to the salt content of the river water: 12th and 13th biennial reports of the State Engineer of New Mexico, p. 77-118.