Abstract

RODRIGUEZ-GARCIA, Gabriel  and  SABRICA, Carlos. U-Pb zircon ages in neisses and amphibolites of the Puquí Complex and the Valdivia Group, and new stratigraphic nomenclature suggested for units around the Hidroituango Project. Bol. cienc. tierra [online]. 2023, n.54, pp.27-47.  Epub Mar 11, 2024. ISSN 0120-3630.  https://doi.org/10.15446/rbct.n54.109380.

New U-Pb in zircon ages obtained in metamorphic units of the Puquí Complex and the Valdivia Group, from a sector in northwestern Antioquia, between the Central and Western Cordilleras of the Northern Andes, evidence three different regional geological events: 1) crystallization ages during the Ordovician (La Vereda Rodriguez Gneiss), comparable to ages obtained further east and south in the La Miel Gneiss and La Perla Gneiss; 2) Metamorphism and anatectic metamorphism during the Middle Triassic (Pescadero Gneiss, Toledo Porphyroblastic Gneiss, Puente La Palestiºna Amphibolites, and ages in deformed rocks), a regional event common to other gneissic bodies of the Central Cordillera in the Tahamí Terrane; 3) maximum Cretaceous depositional ages (ca. 72 Ma) in a biotite-moscovite-quartz schists unit, similar to those obtained in metamorphic and deformed rocks in the western margin of South America, and interpreted as a result of the collision of the oceanic Plateau against the continental margin. We propose a new nomenclature for previously mapped units within the Puquí Complex, such as the La Vereda Rodríguez Gneiss, the Toledo Porphyroblastic Gneiss, and the Puente La Palestina Amphibolites, based on geochronology results and existing mapping.

Keywords : Colombia; U-Pb ages; Metamorphic rocks; Tahamí; Western and Central cordilleras.

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