Structure and Deformation of the Sudbury Impact Crater

Abstract

<p>Digital elevation models (DEM) can be used for a multitude of applications. Under ideal circumstances, calibration of a remotely acquired estimate of topographic elevation is calibrated through use of ground control points (GCP) which would be ubiquitous, seamlessly joining remotely sensed data and high accuracy check points. In reality there are many areas on the earth’s surface which are difficult, expensive, or dangerous to access. Under these circumstances, the acquisition of GCPs may not be realistic and relative DEMs must be used. Innovative methods must then be used to determine the relative error associated with a DEM in a given study area. The method presented in this paper compares three DEMs (ASTER, CDED, SRTM) derived from independent acquisition systems to determine their relative errors.</p> <p>The ASTER DEM data was chosen for a lineament analysis study in north central Ontario, Canada. This study used a quantitative digital approach to determine the density of lineaments mimicking the geometry of the northern Sudbury Igneous Complex contact (SIC). The study revealed a lineament density at ~25km north of the northern SIC contact, suggesting a ring structure from an ancient multi-ring impact basin. This argument is supported by findings of the pattern of plagioclase clouding intensities in Matachewan dykes in the vicinity of the ring structure. The orientation of the dykes may have some connection to the faulting and block rotation caused by crater wall collapse.</p> <p>Paleomagnetic data from the norite in the SIC and Foy Offset dyke combined with an unconstrained magnetic inversion of the Foy Offset dyke suggest that the Sudbury Structure has not been folded, but instead has been deformed by brittle deformation.</p>