Mapping the northern and southern extent of the Socorro midcrustal magma body by wide-angle seismic reflections
— Kenneth H. Olsen, Dan J. Cash, and John N. Stewart

This paper reviews seismological studies of a deep seated, but not readily apparent, volcano-tectonic structure beneath the Albuquerque basin. This is a midcrustal magma body (MCMB) whose existence has been inferred from various geophysical evidence. Although the details and mechanisms are presently obscure, this anomalous feature probably plays an important role in the evolution of the Rio Grande rift. Filling in these details is the aim of continuing research by many investigators. We concentrate here on inferred physical properties of the MCMB, based largely on our "wide-angle" seismic refraction profiling experiments, but also including reviews of microearthquake studies and vertical profiling work by others. Figure 1 is a schematic representation of the three methods. Data from each seismological method emphasize somewhat different aspects of the MCMB and need to be combined to form an integrated picture. Discussion of other kinds of geophysical evidence has been reviewed by Sanford and others (1977) and by Rine-hart and others (1979).