Volcanic stratigraphy, structural geology, and K-Ar geochronology of the Durango area, Durango, Mexico

Simple item page
dc.contributor.advisorMcDowell, Fred W. (Fred Wallace), 1939-
dc.creatorKeizer, Richard Paul, 1947-
dc.date.accessioned2020-10-27T19:35:50Z
dc.date.available2020-10-27T19:35:50Z
dc.date.issued1973
dc.description.abstractDetailed mapping in the Sierra Madre Occidental, near Durango City, Mexico, has documented more than 700 m of rhyolitic volcanic rock (Río Chico Formation) overlain by basaltic lava-flow rock (Metates Formation). The Río Chico Formation consists of nine persistent ash-flow sheets, each covering several hundred square kilometers, intercalated with minor ash-flow sheets, basaltic and rhyolitic lava-flow rock, and rhyolitic air-fall tuff. Rhyolitic plugs intrude the Río Chico Formation in several locations. The rhyolitic volcanic rock overlies an older sequence of andesitic volcanic rock. Two of the older ignimbrites (the Aguila and Santuario Members) were erupted from the Chupaderos Caldera centered about 8 km north of Durango City. Faults peripheral to the caldera are located about 10 km south and west of Durango City. Rhyolitic to dacitic flow domes south and west of Durango City mark the outer margin of the caldera. They were emplaced during an interval of erosion and caldera collapse which followed eruption of the Aguila ignimbrites. Later eruption of the Santuario ignimbrites buried much of the irregular post-collapse topography. A younger sequence of ignimbrites (Tunal Member) thickens considerably toward a probable source south of the mapped area. Still younger ignimbrites originated from an eruptive center(s) outside the map area, possibly to the west. The nearly horizontal ignimbrites are broken by north- and northwest-trending normal faults with displacements in the 200 m range. Initial faulting occurred during eruption of the ignimbrites, possibly because of collapse. Major episodes of block faulting also occurred before and after eruption of the rocks in the Metates Formation. K-Ar dates on the volcanic sequence indicate 3 distinct eruptive events. A tentative K-Ar date on a plagioclase separate from one sample of the basal andesite sequence is 46.4 m.y. Nineteen K-Ar ages on feldspar and biotite of the Río Chico Formation indicate that rhyolitic volcanism was in progress 29 to 31 m.y. ago. Three K-Ar dates on amphibole and feldspar from the Metates Formation indicate that basaltic volcanism, and concurrent block faulting, was in progress about 12 m.y. agoen_US
dc.description.departmentEarth and Planetary Sciencesen_US
dc.format.mediumelectronicen_US
dc.identifier.urihttps://hdl.handle.net/2152/83473
dc.identifier.urihttp://dx.doi.org/10.26153/tsw/10470
dc.language.isoengen_US
dc.relation.ispartofUT Electronic Theses and Dissertationsen_US
dc.rightsCopyright © is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.en_US
dc.rights.restrictionOpenen_US
dc.subject.lcshVolcanology--Mexico--Durango (State)
dc.subject.lcshGeology, Stratigraphic
dc.subject.lcshGeology, Structural--Mexico--Durango (State)
dc.subject.lcshPotassium-argon dating
dc.subject.lcshGeological time
dc.titleVolcanic stratigraphy, structural geology, and K-Ar geochronology of the Durango area, Durango, Mexicoen_US
dc.typeThesisen_US
dc.type.genreThesisen_US
thesis.degree.departmentGeological Sciencesen_US
thesis.degree.disciplineGeological Sciencesen_US
thesis.degree.grantorUniversity of Texas at Austinen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Artsen_US

Access full-text files

Original bundle

Now showing 1 - 2 of 2
Thumbnail Image
Name:
2019_1062.pdf
Size:
83.36 MB
Format:
Adobe Portable Document Format
Description:
Final pdf File
Download
No Thumbnail Available
Name:
2019_1062-TEXT.xml
Size:
274.18 KB
Format:
Extensible Markup Language
Description:
XML Text File
Download

License bundle

Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.64 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

UT Electronic Theses and Dissertations