Petrology, geochemistry and geochronology of lower-crustal xenoliths, Central Mexico

Research output: ThesisDoctoral Thesis

Abstract

Lower-crustal xenoliths from Quaternary-age volcanic vents in central Mexico have diverse lithologies. Their petrographic and geochemical characteristics are similar to other xenoliths collected in Mexico and a similarity in lithology probably exists over a large portion of the Mexican lower crust. Meta-igneous granulites range widely in composition and may have been formed in an arc-setting as cumulates or liquids, since most retain trace element concentrations that are similar to those found in typical arc-related rocks. Meta-sedimentary granulites are similar to depleted shales and may represent either the basement that existed before arc volcanism created the meta-igneous granulites, or alternatively, sediments that were obducted from a subducting slab. U-Pb zircon geochronology suggests that the protoliths for metaigneous xenoliths either formed from subduction-related magmas in Paleozoic to Precambrian time, or alternatively, formed in the mid-Tertiary from Sierra Madre Occidental magmas that assimilated older, zircon-bearing crust. 
Original languageAmerican English
QualificationPh.D.
Awarding Institution
  • Department of Earth and Planetary Sciences
Supervisors/Advisors
  • Bowring, James Luhr and Samuel, Advisor, External person
StatePublished - Dec 1990
Externally publishedYes

Disciplines

  • Earth Sciences
  • Geochemistry
  • Geology

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