Mesoproterozoic Oaxaquia-type basement in peri-Gondwanan terranes of Mexico, the Appalachians, and Europe: T-DM age constraints on extent and significance
Por:
Keppie J.D., Murphy J.B., Nance R.D., Dostal J.
Publicada:
1 ene 2012
Categoría:
Geology
Resumen:
The basement of most peri-Gondwanan terranes in Mexico, the Appalachians, the Caledonides, and the Variscides is buried beneath younger Ediacaran arc, Palaeozoic passive margin, and/or Mesozoic-Cenozoic platformal carbonates. However, it is exposed in the Oaxaquia terrane of Mexico (Oaxacan, Novillo, Huiznopala, and Guichicovi complexes), where it is characterized by ca. 1.0-1.3 billion year protolith ages and igneous rocks with depleted mantle model ages (T-DM) of 1.35-1.77 billion years. The T-DM ages represent a bulk average composition of the source and can be used as a tracer; these TDM ages overlap with those in ca. 546 Ma arc clasts from the 65.5 Ma Chicxulub bolide breccia, suggesting that the northern Maya block is also underlain by Oaxaquia-type basement. Similar T-DM ages occur in Ediacaran arc rocks in Suwannee (Florida), NW Avalonia, Ganderia, Iberia, Armorica, and Bohemia, and in lower Palaeozoic plutons cutting adjacent Palaeozoic passive margin rocks (Acatlan Complex, G
Filiaciones:
Keppie J.D.:
Univ Nacl Autonoma Mexico, Inst Geol, Dept Reg Geol, Mexico City 04510, DF, Mexico
Murphy J.B.:
Department of Earth Sciences, St. Francis Xavier University, Antigonish, NS B2G 2W5, Canada
Nance R.D.:
Department of Geological Sciences, Ohio University, Athens, OH, United States
Dostal J.:
Department of Geology, Saint Mary's University, Halifax, NS B3H 3C3, Canada
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