Formation and Evolution of
the Chiapas Massif, SE Mexico: U/Pb and 40Ar/39Ar
geochronology on basement rocks.
UC MEXUS-CONACYT Collaborative Grant 2001
Bodo Weber (project Co-director CICESE), Geology Department, CICESE
Kenneth L. Cameron (project Co-director UC), University of California, Santa Cruz
Margarita
López Martínez,
Departamento de Geología, CICESE
Duration
07/01/2001 – 12/31/2002
Mexico was assembled during the past 200 Ma from perhaps 15 separate basement blocks (terranes). On the other hand, a 1 Ga microcontinent referred to as Oaxaquia, is inferred to underlie most of central, eastern and southern Mexico. Its southeastern boundary is still unclear since 1 Ga basement was detected in the western Maya terrane. Therefore, great significance must be attached to the metamorphic basement of the Chiapas Massif whose age and origin is almost unknown. We propose a geochronologic study by the U/Pb and 40Ar/39Ar methods to unravel the geological history of the Chiapas Massif, and then attempt to correlate those rocks with rocks of similar age from other parts of Mexico. Collaborators from CICESE will be responsible for sample preparation and 40Ar-39Ar dating, and both UCSC and CICESE personnel will date the rocks by the U/Pb method in the isotope lab at UCSC. This type of research may ultimately lead to a redefinition of terranes in eastern and southern Mexico and to their correlations with Laurentia and Gondwana. This project will start a new collaboration between UCSC and CICESE. It will enhance the sample preparation capabilities at CICESE, and finally, it will lay the foundation for future NSF and CONACYT proposals.
Cooperation with other institutions
Ludwig-Maximilians-Universität
München, Germany