Font Size: a A A

Depositional and tectonic history of the Guerrero Terrane, Sierra Madre de Sur; with emphasis on sedimentary successions of the Teloloapan area, Southwestern Mexico

Posted on:2005-07-06Degree:Ph.DType:Thesis
University:Memorial University of Newfoundland (Canada)Candidate:Guerrero-Suastegui, MartinFull Text:PDF
GTID:2450390008481598Subject:Geology
Abstract/Summary:
The Pacific margin of Mexico is formed by Upper Jurassic-Lower Cretaceous arc-related successions of the Guerrero Terrane. The Guerrero Terrane in southwestern Mexico is divided into three subterranes: from west to east: the Zihuatanejo-Huetamo subterrane, Arcelia-Palmar Chico subterrane, and Teloloapan subterrane.; This thesis research targets the Teloloapan subterrane and is aimed at establishing its stratigraphy, sedimentology, petrography and geochemistry as the basis for an improved understanding of its tectonic history. The Teloloapan subterrane contains a thick Lower Cretaceous age sequence of volcanic, volcaniclastic, and carbonate rocks (the arc-related succession), which is covered by Upper Cretaceous mostly deep-water siliciclastic rocks (the sedimentary cover successions). All rocks are strongly deformed.; The arc-related succession contains three formations (Villa Ayala, Acapetlahuaya and Teloloapan formations) showing concordant and transitional boundaries. Facies analysis of the Villa Ayala and Acapetlahuaya formations (Berriasian-Late Aptian) records the construction of volcanic build-ups and their destruction by gravity-current processes that formed slope-apron deposits. Carbonate rocks of the Teloloapan Formation developed on top of extinct volcanoes and formed an Aptian-Albian carbonate platform.; The Miahuatepec and Mezcala formations constitute the sedimentary cover succession. The Mezcala Formation is comprised of interbedded sandstone and shale with minor thin-bedded limestone and calcareous breccias. The Miahuatepec Formation is a thick sequence of interbedded sandstone and shale with minor thin-bedded limestone. Facies analysis shows both units were deposited by low- to high-concentration turbidity currents on the middle to lower parts of submarine fans.; Volcaniclastic and epiclastic sandstones from the arc-related succession are rich in volcanic lithic grains derived from contemporaneous volcanic source. They have an undissected to transitional arc provenance (terminology of W. R. Dickinson). Geochemical data indicate a mafic to felsic volcanic source with a calc-alkaline affinity. REE patterns are similar to those of evolved intraoceanic arcs.; Sandstones from the Mezcala Formation show quartzolithic and carbonate-rich petrofacies, while the sandstones of the Miahuatepec Formation are mainly quartzolithic. Both formations were derived by erosion of volcanic sources and have a transitional to dissected arc provenance. (Abstract shortened by UMI.)...
Keywords/Search Tags:Guerrero terrane, Succession, Teloloapan, Volcanic, Formations, Sedimentary
Related items