A long-lived active margin revealed by zircon U–Pb–Hf data from the Rio Apa Terrane (Brazil): New insights into the Paleoproterozoic evolution of the Amazonian Craton

From microanalysis to supercontinents: Insights from the Rio Apa Terrane into the Mesoproterozoic SW Amazonian Craton evolution during Rodinia assembly

“…These grains are predominantly classified as low-to medium-grade metamorphic apatite (Figure 12A), in agreement with chemical characteristics of metamorphic/metasomatic apatite (Glorie et al, 2019;Henrichs et al, 2019Henrichs et al, , 2018Ribeiro et al, 2020b). Apatite from samples FMR147 and FMR42 record c. 400-350 Ma younger ages than the crystallization age of the Caracol Complex (Faleiros et al, 2016;Plens, 2018;Ribeiro et al, 2020a;Teixeira et al, 2020). These apatite ages are interpreted to reflect (re)crystallization in response to a medium-grade metamorphic/metasomatic event affecting the Caracol Complex.…”

“…Zircon U-Pb-Hf data collected across the RAT suggest that the Western and Eastern Terranes were developed during advancing and retreating episodes of a single accretionary orogenic system, following a crustal reworking trend (from ~2.7 to 1.8 Ga) and input of more juvenile magmatism (ca. 1.8 to 1.72 Ga) due to a possible slab roll back (Figure 1D, Ribeiro et al, 2020a). Given that both 'terranes' share a genetic relationship, we will adopt the terms Western and Eastern domains hereafter to avoid the tectonic significance of the term "terrane".…”

“…The Paleo-to Mesoproterozoic Rio Apa Terrane (RAT), an allochthonous fragment of the Amazonian Craton (Figure 1A), is an example of a long-lived accretionary orogen developed along the SW Amazonian margin (Cordani et al, 2010;Faleiros et al, 2016;Ribeiro et al, 2020a;Teixeira et al, 2020), which has undergone a long and complex metamorphic evolution. The RAT is predominantly composed of (meta)igneous and subordinate metasedimentary rock units ranging from 2100 to 1720 Ma, overprinted by regional thrusting at c. 1300 Ma (Figure 1B, C) (Cordani et al, 2010;Ribeiro et al, 2020a;Teixeira et al, 2020).…”

“…Although the crustal development of the RAT is well studied on the basis of whole-rock geochemistry and zircon dating and isotopic studies (U-Pb-Hf) (Faleiros et al, 2016;Lacerda Filho et al, 2016Plens, 2018;Plens et al, 2013;Ribeiro et al, 2020a;Teixeira et al, to uncertain tectonic inferences.…”

Cryogenian glaciostatic and eustatic fluctuations and massive Marinoan-related deposition of Fe and Mn in the Urucum District, Brazil

“…S12) (Cordani et al,. 2010;Redes et al, 2020;Teixeira et al, 2020;Ribeiro et al, 2020). Hence, these comprise the proximal sediment sources for the Jacadigo Group.…”