| Detailed lithological and structural mapping was carried out in an area north of Tweed, Ontario, Canada, along the domain boundary between the Mazinaw and Grimsthorpe (Elzevir) domains of the Composite Are Belt, Grenville Province. The area, known as the Mooroton Shear Zone, is dominated by deformed metavolcanic, metavolcaniclastic, metasedimentary, and plutonic rocks that underwent at least two phases of ductile deformation during the Mesoproterozoic. Petrographic and thermometric analysis of metamorphic mineral assemblages places the deformed rocks within the amphibolite metamorphic facies, with metamorphism outlasting deformation. Polymictic metaconglomerates, possibly belonging to the 1150 Ma-age Flinton Group, were deposited in a fluvial environment characterized by variable braided stream discharge and sediment load. Structural analysis of the Mooroton Shear Zone along a transect perpendicular to the domain boundary determined that a thrusting regime led to the present configuration of deformation fabrics, with later minor extension resulting in hydrothermal vein systems. |
