Rift volcanics of the Albuquerque Basin--Overview with some new data
Albert M. Kudo
This paper summarizes and describes volcanic rocks and features of the Albuquerque basin. Although most of the data come from a review of publications (Aoki and Kudo, 1976; Kelley and Kudo, 1978; Bald- ridge, 1979; Zimmerman and Kudo, 1979), new data also are presented. Three major volcanic fields, the San Felipe, Albuquerque, and Cat Hills, and approximately eleven other small centers occur in the basin (fig. 1). The greatest volume of material erupted is basalt, both olivine tholeiite and hypersthene-normative alkali basalt with a characteristic- ally high-Al203 content; however, calc-alkalic high-K andesite, and very minor syenite and rhyolite are present. The oldest exposed volcanic centers may be at Black Butte at the southern end of the basin, at 24 my. (Bachman and Mehnert, 1978), and at Mohinas—Hidden Mountain (no date available) on the west side of the basin and west of the Lucero uplift. The youngest volcanic feature is Cat Hills, dated at 140,000 years (Kudo and others, 1977).
Geomorphically, not a great variety of volcanic features are found in the basin. Volcanoes are generally small, but such features as shield and cinder cones, cone sheets, maar craters-diatremes, and lava-capped mesas are common. Cinder cones at Cat Hills are truly outstanding, displaying symmetrical hills topped by shallow summit craters. Lava flows are intermediate between aa and pahoehoe.
In the following sections, volcanic features are treated in chronological order. Where new data are available for some centers, these are presented in some detail; otherwise, only a summary is given. This paper attempts to redefine conditions for magma generation within the rift.
- Kudo, Albert M., 1982, Rift volcanics of the Albuquerque Basin--Overview with some new data, in: Albuquerque Country II, Grambling, J. A.; Wells, S. G., New Mexico Geological Society, Guidebook, 33rd Field Conference, pp. 285-289.