Palaeoproterozoic to Mesoproterozoic Geology of North Queensland

Deformation & metamorphismGilbert Fold beltRegional studies have suggested the following eventsD1• mainly E-W folds with strong cleavage/foliation• dominant regional structures;• lower greenschist to amphibolite metamorphism• usually thought to be ~1590Ma, based on SHRIMP dates from Dargalong areafarther north.D2• approx N-S folds superimposed on E-W structures,• restricted to E half of outcrop area;• multiple mesoscopic fabrics;• most workers have associated D2 with peak amphibolite facies metamorphismand emplacement of Forsayth Supersuite (S-type anatectic granites) andcommon metamorphic zircon growth at 1550-1560MaD3 - E-W folds, restricted to central part of areaLater open folds, possibly early Palaeozoic