Andean-type, bivergent crustal shortening in the Rinkian orogen: New constraints on the tectonic evolution of Laurentia–West Greenland in the Paleoproterozoic

Abstract The “Rinkian belt” of West Greenland is a metamorphic terrain Paleoproterozoic age comprising: (1) the north Rinkian fold-thrust belt (FTB)—a pro- or fore-arc domain, highly deformed and metamorphosed with widespread anatexis; (2) Prøven Igneous Complex—a magmatic arc characterized by hypersthene granitic rocks (“charnockites”); (3) south FTB—an inverted back-arc basin; 4) continental margin foreland. Recognition this tectonic architecture demonstrates that “Rinkian” bona fide orogenic belt—the orogen— not simply imbricated lower plate Nagssugtoqidian orogen. Arc plutons Complex were emplaced into Karrat Group at ca. 1.90–1.85 Ga, dividing basin retro-arc domains. In former—the FTB—WSW-directed thrusting (deformation events D1-D2) high-grade metamorphism taking place 1.875 Ga continuous through 1.850 peak temperature 1.830 Ma accompanied anatexis in units Complex. domain—the FTB—thrusting to E (D1) began 1.870 followed W (D2) 1.830–1.820 displacement focused major high-temperature ductile shear zone which carried hanging wall an Andean-type, crustal-scale, “pop-up” structure. High-temperature deformation continued during D3 when pro-arc, arc, domains shortened bivergent detachment folding 1.820–1.810 Ga.