The Jurassic system in east-central New Mexico
— Spencer G. Lucas, Kenneth K. Kietzke, and Adrian P. Hunt

Jurassic sedimentary rocks are widely exposed in east-central New Mexico (Fig. 1). These rocks pertain to four rock stratigraphic units (Entrada, Todilto, Bell Ranch and Morrison) and represent eolian, lacustrine and fluvial deposition during the middle to Late Jurassic.

Although Marcou (1855) first identified Jurassic strata in east-central New Mexico, no attempt, other than Mankin (1958a, 1972), has been made to analyze the stratigraphy, sedimentology and paleontology of the Jurassic in this part of the state. This paper presents such an analysis, based primarily on data reported by earlier workers or collected by ourselves from 86 control points in east-central and northeastern New Mexico (Fig. 2). Notes to the text of this paper are indicated by numbers in brackets (e.g., [1]) and are in Appendix 1. Rock colors follow the classification of Goddard et al. (1979), and UNM refers to the Department of Geology, University of New Mexico.