Evolution of the Eocene Galisteo Basin, north-central New Mexico

Abstract

The Galisteo Formation (Eocene) consists of 261 to 1,295 m of red to white mudstone, sandstone and conglomerate deposited in a continental basin located between Albuquerque and Santa Fe (fig. 1). Terrestrial fossils, coarse-grained sedi- ment, crossbedding, channeling and lateral variation in lith- ology indicate that the Galisteo was deposited in fluvial chan- nels and broad flood plains feeding sediment into a progres- sively deepening and enlarging basin (Baltz, 1978; Gorham, 1979; Stearns, 1943). The Galisteo crops out in isolated patches throughout north-central New Mexico, but the Hagan basin contains the most complete and least disturbed section; this is the area in which the present investigation was concen- 1972). The Galisteo rests on the Mesaverde with slight angular trated, although data from surrounding areas are included in the results. The most important previous work on the Gal isteo includes the following: Disbrow and Stoll (1957), Galusha and Blick (1971), Harrison (1959), Kelley and Northrop (1975), and Stearns (1943, 1953b). Recent papers discuss in more detail the economic (Chenoweth, this guidebook; Moore, this guide- book) and paleontologic (Lucas and Kues, this guidebook) resources of this formation. Gorham (1979) recently has com- pleted a detailed stratigraphic, sedimentologic, petrologic and paleogeographic study of the Galisteo, and the interested reader is referred to this work for details not contained in the present report.