1 Distributed volcanic fields of the southwestern U.S.

This session invites submissions from various disciplines (e.g., petrology, tectonics, geophysics, geochronology) that explore distributed volcanism in the southwestern U.S. Topics of interest include spatio-temporal trends, magma compositions, and mantle and/or crustal controls on volcanism.

Monday, 18 May 2026
8:00 AM - 12:00 PM
Alvarado A

The Albuquerque Volcanoes Fissure and Potential Factors Controlling Its Segmentation

Paper number: 1-3
Program: Technical Sessions
Time: 8:45 AM – 9:05 AM

Authors

  • Larry Crumpler Presenting Author
    New Mexico Museum of Natural History and Science, ALBUQUERQUE, New Mexico

Abstract

The Albuquerque Volcanoes fissure is an unusually long eruptive fissure characterized by en échelon segmentation over several scales. The fissure is more akin to fissures in modern Iceland and Hawaiian eruptions that many continental monogenetic eruptions. Linear alignments of vents and fissure eruptions are common in many of the distributed volcanic fields of the Southwest but single eruptions from continuous fissures are less common. This study examines whether segmentation of the Albuquerque Volcanoes fissure resulted from depth variations in stress orientation arising from vertical differences in crustal strength (likely Youngs modulus) in the Rio Grande rift. The ~ 6 km long Albuquerque volcanoes fissure trends N0.9°E and is further subdivided into north  and south segments rotated as much as 2.8°E relative to the primary fissure trend. Each of the segments consists of an alignment of several scoria and spatter vents, each of which also have through-going shorter fissures centered on the principal edifices that are rotated as much as 12.8°E to 21°W relative to the primary fissure. Observed orientations of Quaternary faults in the central Rio Grande rift (north-south) as well as modern regional strain vectors imply a nearly east-west least principal stress direction consistent with the orientation of the primary fissure. Eastward rotation of the north and south fissure segments and additional rotation of shorter local fissure within eruptive centers relative to this orientation suggests progressive rotation of the associated dike through the lower part of the Neogene rift fill section and upper more loosely consolidated late alluvial sediments. Several factors are considered for this rotation of stress and it is speculated that decreased crustal stiffness in the upper Neogene section and corresponding simple shear may play an important role in the segmentation of the fissure.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410592

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