Chromite Exploration and Deformation Monitoring Through PSInSAR

Abstract

This thesis consists of two independent studies, i) the exploration for chromite in the Quesnel terrain, British Columbia, using terrestrial geophysics, and ii) urban deformation monitoring in the Dallas Forth Worth Metroplex using PSInSAR. Chromium is a critical mineral, essential in industry, being necessary to produce stainless steel. British Columbia hosts a range of podiform chromite occurrences throughout the Quesnel Terrane. One such occurrence was investigated using ground based magnetic surveys and rock sample analysis. The results of the ground based magnetic survey allowed for a precise delineation of the serpentinized ultramafic unit, and the identification of a conjugate fault set interpreted to be related to the regional NS dextral shear system. The improved knowledge of the serpentinized zone will improve the targeting of future exploration of the chromite pods hosted in ultramafic bodies, while the identification of the shear system provided targets for the exploration of hydrothermal deposits. The analysis of the rock samples resulted in the interpretation of the relative chronology of the alteration and deformation of the chromite. Non-linear surface deformation is a common phenomenon with numerous causes which can have significant impacts on local infrastructure in urban environments. The temporal and spatial coverage of the Sentinel-1 satellite mission acquisitions make it suitable to test the capability of persistent scatterer interferometry to sample non-linear deformation such as seasonal changes. Ninety-seven scenes from Sentinel-1 were acquired over the Dallas-Fort Worth Metroplex and were processed using the StaMPS algorithm. The PS time series results were compared with permanent GNSS station time series within the SAR footprint using wavelet analysis. The derived global wavelet spectrum and scalogram provided the power of the frequency contributions of deformation processes over time. The GNSS station positions and persistent scatterers in the surrounding areas were interpreted and compared for seasonal deformation. Most GNSS stations analyzed exhibited similar annual deformation to the persistent scatterers located nearby, with 7 out of 19 showing the same peak frequency. Results demonstrate the utility of these observations and the processing strategy for the interpretation of non-linear deformations from PSI analysis of Sentinel-1 data.