A review of the volcanic history and stratigraphy of northeastern New Mexico, the Ocate and Raton-Clayton volcanic fields

Volcanic rocks of northeastern New Mexico lie on the eastern flank of the Sangre de Cristo Mountains and can be divided into two major fields, the Ocate and the Raton-Clayton volcanic fields. These two fields are Miocene-Pleistocene in age and constitute the northeastern extension of the Jemez lineament. The Ocate lavas erupted in a series of five pluses over a 7 m.y. period and, based on geochemical and petrographic criteria, are delineated into five rock types: alkali olivine-basalt (AOB), transitional olivine-basalt (TOB), xenocrystic basaltic andesite (XBA), olivine andesite (OA) and dacite (Nielsen and Dungan, 1985). According to Stormer (1972b), the Raton-Clayton volcanic field can also be divided into five rock types: (1) Raton-Clayton alkali olivine basalts, (2) Red Mountain dacites and andesites, (3) Sierra Grande pyroxene andesite, (4) a feldspathoidal group and (5) the Capulin-type basaltic lavas.