Crustal Structure Beneath Hudson Bay from Ambient-noise Tomography - Implications for basin formation

The Hudson Bay basin is the least studied of the four major Phanerozoic intracratonic basins in North America, which include the hydrocarbon-rich Williston, Illinois and Michigan basins. This study focuses on determining how the Hudson Bay basin formed and on regional crustal structure based on ambient-noise tomography. Two hypotheses are tested, the first suggesting subsidence due to eclogite phase transformation and the second suggests subsidence from lithospheric extension resulting in crustal thinning. Results show asymmetric cross-correlation functions, for which we have adopted an alternative method to averaging cross-correlations, yielding better-defined dispersion ridges. Tomographic pseudo-sections show compelling evidence suggesting crustal thinning as the main event in basin formation.