Structural Characterization of the Sudbury Impact Structure, Canada using current remote sensing datasets

English Abstract:

This study uses current high resolution spatial and spectral orbital datasets to determine the extent and characterize structural features around the Sudbury impact structure, ON, Canada. With an apparent diameter anywhere from 150 to 290 km, the impact structure is proposed to be a multi-ring complex impact structure. Several ring structures have been hypothesized around the crater structure, extending 90 – 200 km beyond the main basin area. Due to the extensive post impact deformation and tectonism, this study focussed on areas north and west extending ~150 km beyond the Sudbury Igneous Complex (SIC). Lineament trends were extracted using automatic extraction algorithms on shaded relief maps (using DEMs, 30 m resolution), and Landsat-7 ETM+ SWIR data. Linear edge enhancement and directional filtering methods were applied to the data to enhance the edges of drainage systems, landforms, and linear features prior to extraction. Landsat-7 band 5 was determined to be the most suitable band for lineament extraction. A more comprehensive set of lineaments were extracted from shaded relief maps with different sun azimuth directions (between 0^o–315^o). The extracted lineaments were statistically analyzed to determine lengths, densities to generate rose diagram, and assess lineament density. In total 13,287 lineaments were extracted with feature lengths ranging from 1 to 9000 m. The lineaments were then compared to known geology in order to determine the source of deformation - either resulting from the main impact event or from later deformation. Three structural trends were observed from plotting rose diagrams- a majority trending north-south and northwest-southeast direction. A minor trend running northeast-southwest. Future work will include analyzing band ratio composite maps using Landsat 8, ASTER, and Radarsat data in order to extract lineaments, determine structural trends, types of lineament, and investigate any evidence of radial and concentric structures.