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The Mogollon-Datil volcanic field is a large silicic volcanic field in western New Mexico (Mogollon Mountains-Datil, New Mexico). It is a part of an extensive Eocene to Oligocene volcanic event which includes the San Juan volcanic field in southwestern Colorado, the Trans-Pecos volcanic field in west Texas and north central Mexico, the Boot Heel volcanic field in the bootheel of southwestern New Mexico and adjacent areas of Arizona and Mexico; and the vast volcanic field of the Sierra Madre Occidental of western Mexico. The Mogollon-Datil volcanic field was formed in "four discrete pulses representing synchronized activity of two separate cauldron complexes".〔McIntosh, W. C.; Chapin, C. E.; Ratte, J. C. and Sutter, J. F. (1992) "Time-stratigraphic framework for the Eocene-Oligocene Mogollon-Datil volcanic field, southwest New Mexico" ''GSA Bulletin'' 104(7): pp. 851-871, page 851, 〕 The Socorro, New Mexico region (Socorro-Magdalena caldera cluster) of the central Rio Grande rift hosts an inflating mid-crustal sill-like magma body at a depth of 19 km that is responsible for anomalously high earthquake activity in the vicinity. Earth and space-based geodetic measurements indicate ongoing surface uplift above the (Socorro Magma Body ) at approximately 2 mm/year. ==Formations== The Datil Group,〔Weber, Robert H. (1971) "K-Ar ages of Tertiary igneous rocks in central and western New Mexico" ''Isochron/West'' 1(1): pp. 33–45〕 or series of volcanic and related formations (formerly the Datil Formation〔("Tertiary and Quaternary: Baca Formation" ) Open File Report 94 (1977), New Mexico Bureau of Geology & Mineral Resources, page 88〕) in New Mexico and eastern Arizona represents the extrusive output from the Mogollon-Datil volcanic field.〔Chapin, 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, 〕 Originally the Baca Formation was included in the group,〔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, 〕 but now the group is considered to start with the Spears Formation.〔 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 series consists of the following formations:〔 *Baca Formation, primarily fluvial red shales and sandstones of the Eocene,〔 no longer considered part of the group;〔Tonking, William H. (1957) ''Geology of the Puertecito quadrangle, Socorro County, New Mexico'' New Mexico Bureau of Mines and Mineral Resources Bulletin 41, 〕 *Spears Formation, latitic to andesitic conglomerates, mudflow deposits and thin, interbedded volcanic clastics and sandstones, followed by andesite flows interbedded with some conglomerates and mudflow deposits,〔Brown, David M. (1972) ''Geology of the Southern Bear Mountains, Socorro County, New Mexico'' Thesis, New Mexico Institute of Mining and Technology, Socorro, New Mexico, 〕 approximately 37 Ma; *Hells Mesa Tuff, over 2000 ft thick consisting of ash layers that erupted about 32.1 Ma, rhyolitic tuff with interbedded mudflow deposits and basalts; *A-L Peak Tuff *La Jara'Peak Basaltic Andesite 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mogollon-Datil volcanic field」の詳細全文を読む スポンサード リンク
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