U–Pb SHRIMP ages for the Cerro Bori Orthogneisses, Dom Feliciano Belt in Uruguay: Evidences of a ~800Ma magmatic and ~650Ma metamorphic event
MetadataShow full item record
Neoproterozoic ages of magmatic and metamorphic events were obtained from in situ SHRIMP analysis of zircons from the Cerro Bori Orthogneisses, eastern domain of the Dom Feliciano Belt in Uruguay. Detailed textural analysis of zircons and their ages revealed a much more complex evolutionary history for these rocks than previously thought. Twelve samples were studied and revealed crystallization ages between 802 and 767 Ma, determined from the typical magmatic oscillatory zoning domains from the zircons. These magmatic domains are cut by recrystallization fronts and mantled by metamorphic rims. The recrystallization fronts and rims are interpreted to be related to a high grade metamorphic event with a maximum age of ~676 Ma, whereas the rims considered to be related to partial melting are 654 ± 3 Ma old. The new magmatic ages demand a reinterpretation of the evolutionary history of this crustal segment, which is one of the few occurrences of the early Brasiliano Orogenic Cycle rocks in South Brazil and Uruguay. The metamorphic/partial melting event is inferred to be related to crustal thickening as a consequence of collision of the Rio de la Plata with the Congo and Kalahari cratons, during the amalgamation of West Gondwana.
Showing items related by title, author, creator and subject.
Zoned Monazite and Zircon as Monitors for the Thermal History of Granulite Terranes: an Example from the Central Indian Tectonic ZoneBhowmik, S.; Wilde, Simon; Bhandari, A.; Sarbadhikari, A.B. (2014)The growth and dissolution behaviour of detrital, metamorphic and magmatic monazite and zircon during granulite-facies anatexis in pelitic and psammo-pelitic granulites and in garnetiferous granite from the southern margin ...
The evolution of the metamorphic series in the NW Fujian Province, the NE Cathaysia Block, and the significance in the reconstruction of Precambrian SupercontinentsZeng, Wen (2010)This thesis focuses on the Paleoproterozoic to Late Paleozoic basement evolution of the metamorphic rocks scattered in the NW Fujian Province, the NE Cathaysia Block the southeastern area of South China. Field observation, ...
Precambrian crustal evolution of the eastern North China Craton as revealed by U–Pb ages and Hf isotopes of detrital zircons from the Proterozoic Jing’eryu FormationSun, J.; Yang, J.; Wu, F.; Wilde, Simon (2012)Simultaneous in situ U–Pb dating, trace element and Hf isotopic analyses have been carried out on detrital zircons obtained from sandstones in the Neoproterozoic Jing’eryu Formation from the Eastern Block, North China ...