The volcanic activity of the Mogollon-Datil began near present-day Las Cruces, New Mexico about 36.2 million years ago (mya) with the eruption of the Cueva Tuff from the Organ Caldera. Activity spread to the northwest to the Mogollon caldera by 34.0 mya, and this first pulse of activity died down around 33.5 mya. A second short pulse of activity occurred between 32.1 and 31.4 mya, with activity both in the existing southern part of the field and at a new caldera complex centered west of Socorro, New Mexico. The third and most extensive pulse of activity lasted from 29.0 to 27.4 mya. A fourth small pulse occurred from 26.1 to 24.3 mya.[4][5][6]
The caldera eruptions produced enormous volumes of tuffs across the region. The first two pulses of activity produced a total volume of 3,000 cubic kilometers (720 cu mi) of tuffs, while the third pulse produced over 6,000 cubic kilometers (1,400 cu mi) of tuffs.[7]
The silica-rich caldera eruptions were accompanied by eruptions of less silica-rich (mafictointermediate) volcanic rock. These were mostly andesite during the first eruptive pulse, becoming less silica-rich (mostly basaltic andesite) in later eruptive pulses.[7] The third eruptive pulse was also accompanied by less explosive rhyolite eruptions of the Taylor Creek Rhyolite, which may have come from a single magma chamber less enriched in volatiles.[1]
The initial mafic to intermediate volcanism has chemical signatures typical of calc-alkaline volcanic rock of volcanic arcs. The later eruptions have been attributed to a "mini-plume" produced by the disintegration of the Farallon plate.[8]
The stratigraphic framework for the Mogollon-Datil volcanic field has undergone many revisions.[9] The Datil Formation was originally defined by Winchester in 1920 to include all the extrusive units from the field.[10] The Datil Formation was later promoted to group rank with the addition of some related sedimentary formations, such as the Baca Formation[11][12][13] and the Spears Formation.[12] The base of the group, as originally defined, rests unconformably on the Mesaverde Formation, and the series is succeeded by the Popotosa Formation of the Santa Fe Group.
The stratigraphic framework proposed by Cather, Chamberlin, and Ratte in 1994 divides the units associated with the Mogollon-Datil volcanic field into three groups and removes the Baca Formation:[9]
Volcanic Units
Sedimentary Units
Mogollon Group
tuff of Turkey Springs (24.3 Ma[14]) Bearwallow Mountain Andesite (27 to 23 Ma)
Uvas Basaltic Andesite
La Jara Peak Basaltic Andesite South Canyon Tuff (27.4 Ma[14])
Lemitar Tuff (28.0 Ma[14])
Apache Springs Tuff (28.0 Ma[14]) Bloodgood Canyon Tuff (28.0 Ma[14])
Squirrel Springs Andesite
Shelley Peak Tuff (28.1 Ma[14]) Vicks Peak Tuff (28.4 Ma[14])
La Jencia Tuff (28.7 Ma[14])
Davis Canyon Tuff (29.0 Ma[14])
Sawmill Canyon Formation
Luis Lopez Formation
basaltic andesite of Poverty Creek
Spears Group
South Crosby Peak Formation
Rincon Windmill Formation
Chavez Canyon Formation
Dog Springs Formation Rubio Peak Formation Palm Park Formation
Pueblo Creek Formation Bell Top Formation
Rock Springs Formation
Red Rock Ranch Formation
Piloncillo Sediments
unit of East Red Canyon
sandstone of Monument Park
sandstone of Escondido Mountain
volcaniclastic unit of Canon del Leon
volcaniclastic unit of Largo Creek
lacuna (31.4-29.0 Ma)
Datil Group
Tadpole Ridge Tuff (31.4 Ma[14])
Caballo Blanco Tuff Hells Mesa Tuff (32.0 Ma[14])
Box Canyon Tuff (33.5 Ma[14])
Blue Canyon Tuff (33.7 Ma[14])
Cooney Tuff (34.0 Ma[14])
andesite of Dray Leggett Canyon
Rock House Canyon Tuff (34.2 Ma[14])
tuff of Bishop Peak (34.8 Ma[14]) Kneeling Nun Tuff (34.9 Ma[14])
Bell Top Formation (#3: 35.0 Ma[14]) Sugarlump Tuff
tuff of Farr Ranch
Datil Well Tuff (35.0 Ma[14])
andesite of White House Canyon
Dona Ana Tuff
Squaw Mountain Tuff (35.8 Ma[14])
Achenbach Park Tuff (35.8 Ma[14])
Cueva Tuff (36.2 Ma[14])
Cather, Chamberlin, and Ratte find that the Alum Mountain Formation in the southern part of the field may span the lacuna between the Mogollon and Datil Groups, though they suggest a tentative assignment to the Mogollon Group. Still further south, voluminous volcanic activity in northern Chihuahua took place in this time period and no lacuna exists.[9]
Clasts of the Vicks Peak and La Jencia Tuffs have been found in the gravel beds of the Benavidez Member of the Cerro Conejo Formation in the Rio Puerco valley west of Albuquerque. These suggest that the outflow sheets of the Datil-Mogollon volcanic field reached as far north as the northern edge of the younger Mount Taylor volcanic field, where they interfingered with the Chuska Sandstone and with cherty gravels eroded off the Zuni Mountains. This outflow sheet was subsequently completely eroded away north of the Rio Salado.[15]
^Chapin, Charles E.; McIntosh, William C.; Chamberlin, Richard M. (2004). "The late Eocene-Oligocene peak of Cenozoic volcanism in southwestern New Mexico". In Mack, G.H.; Giles, K.A. (eds.). The geology of New Mexico. A geologic history: New Mexico Geological Society Special Volume 11. New Mexico Geological Society. pp. 271–290. ISBN9781585460106.
^ abcRentz, Shannon P.; Michelfelder, Gary S.; Coble, Matthew A.; Salings, Emily (2018). "U-Pb zircon geochronology of calc-alkaline ash flow tuff units in the Mogollon-Datil volcanic field, southern New Mexico". In Poland, Michael P.; Garcia, Michael O.; Camp, Victor E.; Grunder, Anita (eds.). Field Volcanology: A Tribute to the Distinguished Career of Don Swanson. Geological Society of America. pp. 409–434. doi:10.1130/SPE538. ISBN9780813725383. S2CID214521258.
^ abChapin, Charles E. et al. (1978) "Exploration framework of the Socorro geothermal area, New Mexico" pp. 114–129 In Chapin, Charles E. et al. (editors) Field guide to selected cauldrons and mining districts of the Datil-Mogollon volcanic field Special Publication NO. 7, New Mexico Geological Society, OCLC4960990
^Winchester, Dean E. (1920) Geology of Alamosa Creek Valley, Socorro County, New Mexico with special reference to the occurrence of oil and gas U.S. Geological Survey Bulletin 716-A, OCLC6007605
^ abcRatté, J. C.; Marvin, R. F.; Naeser, C. W.; Bikerman, M. (1984). "Calderas and ash flow tuffs of the Mogollon Mountains, southwestern New Mexico". Journal of Geophysical Research. 89 (B10): 8713. Bibcode:1984JGR....89.8713R. doi:10.1029/JB089iB10p08713.
Elston, W. E. (1976) "Glossary of stratigraphic terms of the Mogollon-Datil volcanic province" pp. 135–145 In Elston, W. E. and Northrop, S. A. Cenozoic volcanism in southwestern New Mexico: A Volume in Memory of Rodney C. Rhodes, 1943–1975 New Mexico Geological Society Special Publication No. 5, Socorro, New Mexico, OCLC2841953
