Magmatic epidote in Archean granitoids of the Carajás Province, Amazonian craton, and its stability during magma rise and emplacement

In the Rio Maria and Sapucaia Domains of Carajás Province, during Mesoarchean, tonalite-trondhjemite-granodiorite (TTG) series (2.98–2.92 Ga; Colorado Trondhjemite) sanukitoid rocks (?2.87 Suite Ourilândia do Norte) were formed. They followed, in Neoarchean (2.75–2.73 Ga), by numerous stocks granitoids similar to A-type granites (Vila Jussara Suite). Despite compositional differences between these granitoids, epidote is a mineral phase common all them, with pistacite contents 26–29 mol% TTGs, 22–33 sanukitoids 25–30 granitoids. The study dissolution kinetics Archean epidotes Province reveals that partial time their crystals was ?4–10 years, corresponding magma ascent rates 4–8 km/year. Magma viscosities at liquidus temperature estimated 105.3 Pa s for TTG 102.5 magma, whereas monzogranitic magmas Vila exhibited viscosity 104.4 s. contrast, tonalitic 103.5 preservation magmatic requires plutons grew an incremental way, Phanerozoic counterparts, stacking small sill-dykes about 100 m thickness each intruded rather cold crust, allowing fast cooling so as prevent complete final emplacement level.