Fold origin of the NE-lobe of the Sudbury Basin, Canada: Evidence from heterogeneous fabric development in the Onaping Formation and the Sudbury Igneous Complex

摘要: Structural analysis of the Onaping Formation, a heterolithic impact melt breccia, and Granophyre in NE-lobe 1.85 Ga Sudbury Igneous Complex (SIC) assist understanding formation Basin. Previously, lack mesoscopic strain fabrics SIC, contrast to pervasive Formation NE-lobe, led interpretations shape as primary. We demonstrate that structures are consistent with deformation fold core controlled by mechanically stronger NE-lobe. Evidence for this interpretation includes (1) presence open structural domes basins, (2) geometry planar mineral fabrics, (3) variation fabric intensity, (4) kinematics prominent faults. Folding affected SIC because is based on dip data fold-related faults cut both Granophyre. Microstructural observations point different temperatures during units initiation folding cooling upon reaching middle greenschist-facies metamorphic conditions.