Regional high-grade metamorphic peak imprint in zircons from the mafic-ultramafic Jacurici Complex, São Francisco Craton, Brazil

• Autor(a) principal: Dias,João Rodrigo Vargas Pilla
• Data de Publicação: 2022
• Outros Autores: Marques,Juliana Charão, Bertolini,Gabriel, Frantz,José Carlos, Friedrich,Betina, Paim,Jhenifer Caroline da Silva, Silveira,Carlos José Sobrinho da, Queiroz,Waldemir José Alves
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Geology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2317-48892022000100306
• topic: Jacurici Complex; São Francisco Craton; Serrinha Block; Salvador Curaça Belt; zircon U-Pb age

Abstract The Cr-rich Jacurici Complex is located at the limit between the Serrinha Block and the Salvador-Curaçá Belt, Northeastern São Francisco Craton. In order to better understand the age span of magmatism and tectonism, we have studied a basement high-grade charnockite orthogneiss, a metanorite of the Complex and a crosscuting undeformed quartz-feldspar pegmatite. For the orthogneiss, SHRIMP U-Pb ages of zircon cores and overgrowth rims yielded, 2966 ± 9 Ma for crystallization and 2091 ± 10 Ma for metamorphism, respectively. Zircons from the metanorite show internal textures consistent with high grade metamorphism. The U-Pb LA-ICP-MS age determination provided a 2099 ± 6 Ma metamorphic age for the Jacurici Complex, indicating it was already emplaced during amalgamation around 2.1 Ga. Zircons from the undeformed quartz-feldspar pegmatite provided a LA-ICP-MS U-Pb age of 2083 ± 11Ma, marking the end of the N-S transcurrence. The magmatic Jacurici Complex age remains undefined, but is equal to, or older than, 2.1 Ga. Therefore, possible correlations with other mafic-ultramafic intrusions, such as the Cu-rich Caraíba Complex, should be reassessed. Our results indicate that the N-S transcurrence ended earlier in the Jacurici Complex region than in the northwestern area of the Salvador-Curaçá belt.