40Ar/39Ar Geochronology, Vent Migration, and Hazard Implications of the Youngest Eruptions in the Raton-Clayton Volcanic Field
Matthew J. Zimmerer
Twenty-seven new 40Ar/39Ar ages provide insight into the timing of ten eruptions in the Raton-Clayton volcanic field. The new ages were determined using the high-sensitivity, multi-collector ARGUS VI mass spectrometer. The ARGUS VI yields an increase in analytical precision compared to older generation mass spectrometers, providing an opportunity to re-assess the youngest eruptions in the field. New ages indicate that nine vents erupted between 368.2±7.3 and 36.6±6.0 ka. The average eruption frequency during this pulse of activity is 1 event per 37 ky. However, repose periods between successive eruptions are highly irregular, ranging too short to measure (i.e., statistically indistinguishable ages) to as much as 130 ky. The five youngest eruptions yield ages between 61.7±1.1 and 36.6±6.0 ka and an average recurrence rate of 1 event per 5 ky, indicating an increase in activity during the late Quaternary. The new ages, combined with published geochronology, reveal a previously unrecognized vent migration pattern in this volcanic field. Beginning at approximately 1.3 Ma, the location of volcanic vents has migrated at a rate of 2.3 cm/yr to the east from an area south of Raton to near Capulin Volcano National Monument. Rates of volcanism and vent migration patterns provide fundamentally important temporal-spatial information should the Raton-Clayon volcanic field enter a new period of eruptive activity.
- Zimmerer, Matthew J., 2019, 40Ar/39Ar Geochronology, Vent Migration, and Hazard Implications of the Youngest Eruptions in the Raton-Clayton Volcanic Field, in: Geology of the Raton-Clayton Area, Ramos, Frank; Zimmerer, Matthew J.; Zeigler, Kate; Ulmer-Scholle, Dana, New Mexico Geological Society, Guidebook, 70th Field Conference, pp. 151-160.