MINERAL CHEMISTRY OF HIGH PRESSURE ECLOGITE-FACIES ROCKS, FROM THE GUAJIRA PENINSULA, COLOMBIA
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Abstract
The high pressure rocks found in the Guajira Peninsula, comprise mainly eclogites with the peak metamorphic paragenesis: omphacite + garnet + quartz + white mica ± kyanite and metapelites with the peak metamorphic paragénesis: quartz + white mica + garnet + kyanite + rutile ± apatite. These rocks register a complex history of tectonic evolution: 1) Prograde growth in two stages, through amphibolite facies, reaching the peak metamorphic paragénesis; 2) hydration of these rocks that enabled galucophane to grow locally; 3) a later not well characterized event that happened in static conditions shown by the growth of clinozoisite; 4) retrogression through amphibolite-facies. The association of eclogites with continental rocks suggest their link to an accretionary prism that was generated during the Cretaceous subduction of the Caribbean plate and the bringing together of a possible continental fragment or the South American continental margin and the Caribbean plate.
Key words : Eclogites, metapelites, Caribbean plate, mineral chemistry
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References
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