PETROGRAFÍA Y GEOQUÍMICA DE LOS METAGABROS DEL RÍO OLIVARES SECTOR NNW DE MANIZALES (CALDAS)
Published 2011-08-08
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Abstract
The Río Olivares Metagabbro is a body of igneous intrusive rocks that outcrops along the Río Olivares at N–NWof the Manizales city (department of Caldas, Colombia). This igneous body is defined by series of centimeterto metric-sized faulted slivers within the western sector of Quebradagrande Complex. Petrographic analyses show rocks with cumulus and isotropic gabbroic textures. The primary minerals are: calcium plagioclase andclinopyroxene, secondary minerals are: amphibole, chlorite, epidote, plagioclase and less quartz, carbonateand occasionally opaque minerals. According to geochemical distribution of major elements, those rocks were generated from fractional crystallization of unique magma showing a typical tendency of tholeiitic series.Taking into account the behavior of trace elements in geotectonic discrimination diagrams, they were generated in an ocean floor setting and their sources coming from an N-MORB segment in the upper mantle. REE patterns normalized with respect to chondrite, show relatively homogeneous patterns, flats and enriched up to 10 times compared to the typical N-MORB. These rocks are part of the oceanic basement of the Early Cretaceous Quebradagrande Complex, and they are affected by my lonitization and ocean floor metamorphism.
Key words: Manizales, metagabbros, N–MORB.
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References
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