Paleoproterozoic sources for Cordilleran-type Neoproterozoic granitoids from the Araçuaí orogen (SE Brazil): Constraints from Hf isotope zircon composition

Reconstructing the metamorphic evolution of the Araçuaí orogen (SE Brazil) using in situ U–Pb garnet dating and P–T modelling

“…Mafic magmatism in the Araçuaí orogen is restricted to rare norite intrusions in the central domain during early orogenic stages (620-580 Ma) and gabbroic intrusions at late orogenic stages from 520 to 500 Ma (De Campos et al, 2016;Tedeschi et al, 2016). Isotopic studies of noritic intrusions and mafic enclaves within granitoids in the central domain show that mafic magmas were derived from mantle melts that underwent substantial crustal contamination by partial melts of Palaeoproterozoic amphibolitic lower crust (Gonçalves et al, 2016;Schannor et al, 2020). Late orogenic mafic intrusions were related to lithospheric extension due to gravitational collapse of the orogen, after significant thickening (De Campos et al, 2016).…”