New Mexico Geological Society · Socorro, NM

(575) 835-5410

Jahir Sanchez1 and Eric Kappus2

1El Paso Community College, 14288 Michele Ann Dr, El Paso, TX, 79938, jahirsanchez29@hotmail.com
2Southwest University at El Paso, 1414 Geronimo Dr, El Paso, TX, 79925

As part of a continuing investigation of trace fossils from the lower-most, Albian Sarten Member of the Mojado Formation, we report the first description of Curvolithus simplex at Cerro de Cristo Rey, Sunland Park, New Mexico. C.simplex is a horizontal, three-lobed trace interpreted as a repichnia. Other traces in this ichnoassemblage that are commonly associated with the Cruziana ichnofacies include Thalassinoides, Arthrophycus, Planolities, scratch marks (and others not yet reported). Our Curvolithus specimensare preserved exclusively in convex epirelief on iron-stained, massive sandstones, interbedded with thin grey shales. At this location the lower contact of the Sarten Member is easily distinguishable from the Mesilla Valley Formation below. Although the base of the Mojado Formation was originally defined arbitrarily by the thickness of sandstone interbeds, or a change in sandstone lithology, we see a distinct change in ichnoassemblages between these two Formations, which may be used to define the contact in the future.

References:

  1. Buatois, L.A., Mangano, M.G., Mikuláš, R. and Maples, C.G., 1998. The ichnogenus Curvolithus revisited. Journal of Paleontology, 72(4), pp.758-769.
  2. Chrz?stek, A. and Nowicka, N., 2021. Trace fossils and depositional environments of the middle Turonian sandstones in the Upper Nysa K?odzka Graben (Sudetes, Poland) revisited. Geological Quarterly, 65(1), pp.65-10.
  3. Cornell, W.C., LeMone, D.V. and Norland, W.D., 1991. Albian ophiuroids from Cerro de Cristo Rey, Dona Ana County, New Mexico. Journal of Paleontology, 65(6), pp.1009-1013.
  4. Heinberg, C., 1973. The internal structure of the trace fossils Gyrochorte and Curvolithus. Lethaia, 6(3), pp.227-238.
  5. Lucas, S.G., Krainer, K., Spielmann, J.A. and Durney, K., 2010. Cretaceous stratigraphy, paleontology, petrography, depositional environments, and cycle stratigraphy at Cerro de Cristo Rey, Doña Ana County, NM. New Mexico Geology, 32(4), pp.103-130.
  6. Scott, R.W., Formolo, M., Rush, N., Owens, J.D. and Oboh-Ikuenobe, F., 2013. Upper Albian OAE 1d event in the Chihuahua Trough, New Mexico, USA. Cretaceous Research, 46, pp.136-150.

2022 New Mexico Geological Society Annual Spring Meeting & Ft. Stanton Cave Conference April 7-9, 2022, Macey Center, Socorro, NM Online ISSN: 2834-5800

Pages: 73