Abstract

The Devonian strata are missing over most of central New Mexico; a Devonian "highland" area. In the southcentral portion of the state, the strata average 85-90 feet thick but are as much as 500 feet thick in southwestern New Mexico.

No Early Devonian strata are known in New Mexico. Late-Middle Devonian strata are present in the Canutillo and Onate Formations. Three faunules of Late Devonian age are present. Strata of Chemung age are present in the Sly Gap and Contradero Formations. No evidence is found for the presence of strata referable to the Finger Lakes Stage of the Late Devonian. Faunules referable to the Cassadaga Stage of the Late Devonian are present in the Thorogood and Rhodes Canyon Formations and in the Ready Pay Member of the Percha Shale. The Box Member contains fossils characteristic of the Conewango Stage of the Late Devonian; latest Devonian faunules are lacking.

Facies changes relate to the Orogrande Basin, the Joronado Basin, Silver City Embayment, the Dona Ana Swell, the Pedernal Landmass, the Caballo Positive, the Organ Positive, the Florida Island and the Hatchet Positive. Epeirogenic and very local mild-orogenic structural tectonics are reflected by the facies.

Faunal evidence supports partial correlation of Devonian strata of New Mexico with the Caballos Novaculite of the Trans-Pecos area, the Woodford Shale of west Texas and Oklahoma, and the Arkansas Novaculite of Oklahoma and Arkansas.