Title: Time-stratigraphic framework for the Eocene-Oligocene Mogollon-Datil volcanic field, southwest New Mexico
Abstract: Research Article| July 01, 1992 Time-stratigraphic framework for the Eocene-Oligocene Mogollon-Datil volcanic field, southwest New Mexico WILLIAM C. McINTOSH; WILLIAM C. McINTOSH 1New Mexico Bureau of Mines and Mineral Resources, Socorro, New Mexico 87801 Search for other works by this author on: GSW Google Scholar CHARLES E. CHAPIN; CHARLES E. CHAPIN 1New Mexico Bureau of Mines and Mineral Resources, Socorro, New Mexico 87801 Search for other works by this author on: GSW Google Scholar JAMES C. RATTÉ; JAMES C. RATTÉ 2U.S. Geological Survey, Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar JOHN F. SUTTER JOHN F. SUTTER 3U.S. Geological Survey, 981 National Center, Reston, Virginia 20222 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1992) 104 (7): 851–871. https://doi.org/10.1130/0016-7606(1992)104<0851:TSFFTE>2.3.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation WILLIAM C. McINTOSH, CHARLES E. CHAPIN, JAMES C. RATTÉ, JOHN F. SUTTER; Time-stratigraphic framework for the Eocene-Oligocene Mogollon-Datil volcanic field, southwest New Mexico. GSA Bulletin 1992;; 104 (7): 851–871. doi: https://doi.org/10.1130/0016-7606(1992)104<0851:TSFFTE>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A time-stratigraphic framework for discontinuously exposed regional ignimbrites in the Eocene-Oligocene Mogollon-Datil volcanic field has been established using correlations aided by 40Ar/39Ar age determinations and paleomagnetic analyses. 40Ar/39Ar age spectra from sanidine separates (25 regional ignimbrites, 85 samples, 97 spectra) yield well-defined plateau ages that are precise (within-sample and within-unit 1σ < ± 0.5%) and agree closely with independently established stratigraphic order. Paleomagnetic remanence directions (404 sites) from individual ignimbrite outflow sheets are generally vertically and horizontally uniform throughout facies ranging from thick (100-500 m), densely welded, proximal ignimbrites to thin (1.5-30 m), unwelded, distal fringes. Between-unit differences in paleomagnetic directions provide useful correlation criteria, particularly for units having ages too close to be resolved using 40Ar/39Ar dating.The Mogollon-Datil time-stratigraphic framework clarifies ignimbrite history and provides improved age control for intercalated lavas and sedimentary rocks. Ignimbrite activity was strongly episodic; outflow sheets were primarily erupted in four discrete pulses representing synchronized activity of two separate cauldron complexes. Activity in the southern complex began at 36.2 Ma near Las Cruces, New Mexico, and subsequently migrated 220 km northwest, culminating in the 28.0 Ma Bursum cauldron. Activity in the northern complex, located west of Socorro, New Mexico, underwent a less defined and more modest 40-km westward migration over its 32.0 to 24.3 Ma life span. The four pulses of ignimbrite activity were (1) 36.2-24.3 Ma, 12 major units, >1,500 km3 total volume; (2) 32.0-31.4 Ma, three major units, >1,500 km3 volume; (3) 29.1-27.4 Ma, nine major units, >6,000 km3; and (4) 24.3 Ma, one major unit. The third and largest ignimbrite pulse was accompanied by extensive rhyolitic dome and flow eruptions in the area between the two main cauldron complexes. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Publication Year: 1992
Publication Date: 1992-07-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 79
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