New Mexico Geological Society Annual Spring Meeting — Abstracts

Invertebrate trace fossils have been identified from shallow marine facies of the Mesilla Valley Formation (Washita Group) at Cerro de Cristo Rey, Sunland Park, NM. Ichnotaxa described here include the invertebrate traces Ancorichnus, Arenicolites, Bergaueria, Cardioichnus, Chondrites, Cochlichnus, Cruziana, Fuersichnus, Helicodromites, Lockeia, Muensteria?, Ophiomorpha, Palaeophycus tubularis, Palaeophycus striatus, Planolites isp., Planolites hebertii, Planolites montanus, Scolicia, Scoyenia, Skolithos, Spongeliomorpha, Taenidium, Teichichnus, and Thalassinoides, as well as arthropod resting traces, a chimney structure, and the biofilm “Kinneyia.” This is the first report on the invertebrate ichnology of the shallow marine units at Cerro de Cristo Rey. This is a medium/high diversity ichnoassemblage, including fugichnia (i.e., Skolithos), fodichnia (i.e., Chondrites), domichnia (i.e., Ophiomorpha, Thalassinoides), repichnia (i.e., Cruziana), paschichnia (i.e., Palaeophycus), and cubichnia (i.e., Cardioichnus, Lockeia), The ichnoassemblage was preserved in tempestites (storm deposits) from below wave base, on the upper/middle continental shelf and contains ichnotaxa representative of the Cruziana ichnofacies.