U-Pb Ages and Hf Isotopes in Zircons from Parautochthonous Mesozoic Terranes in the Western Margin of Pangea: Implications for the Terrane Configurations in the Northern Andes

Autor(es)

Bustamante, Camilo ; Archanjo, Carlos J. ; Cardona, Agustin ; Bustamante, Andres ; Valencia, Victor A.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF GEOLOGY; v. 125, n. 5, p. 487-500, SEP 2017.
• Citações Web of Science: 8

Resumo

U-Pb laser ablation inductively coupled plasma mass spectrometry ages and Hf isotopes in zircons were used to constrain the nature of two geological units representative of the basement of the Central Cordillera of Colombia. Graphite-quartz-muscovite schists from the Cajamarca Complex show inherited detrital zircons supplied mostly from Late Jurassic (ca. 167 Ma), Ediacaran (ca. 638 Ma), and Tonian (Grenvillian; ca. 1000 Ma) sources. These marine volcanosedimentary deposits form an N-trending metamorphic belt in fault contact to the east with orthogneisses and amphibolites of the Tierradentro unit. Zircon U-Pb determinations of the Tierradentro rockspreviously interpreted as Grenvillian basement slicesyielded crystallization ages between 271 and 234 Ma. Initial Hf data reveal that the Tierradentro unit shares isotopic characteristics similar to other Permo-Triassic rocks of the Central Cordillera. In contrast, inherited detrital zircons from the Jurassic metasedimentary rocks suggest that their sources are distinct from the plutonic rocks that crop out in the Central Cordillera with Jurassic crystallization ages. Large xenoliths of the Tierradentro unit within the Ibague batholith indicate that the granodioritic magma mostly intruded a Permo-Triassic basement possibly by exploiting the Otu-Pericos fault. The Jurassic metasedimentary belt is correlated further south with a similar sequence in the Ecuadorian Andes named Salado terrane. (AU)

• Processo FAPESP: 12/14396-0 - Petrogênese de um arco meso-cenozóico da cordilheira central dos Andes colombianos: implicações no crescimento crustal nos Andes do Norte
• Beneficiário: Camilo Bustamante Londono
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto
• Processo FAPESP: 10/19068-6 - Alojamento de magmas em margem convergente: mecanismos de colocação e petrogênese de um arco Meso-Cenozóico da cordilheira central dos Andes colombiano
• Beneficiário: Camilo Bustamante Londono
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto