HR: 1340h
AN: S23B-0257    [Abstracts]
TI: Reprocessing Coincident Refraction and Reflection Data to Constrain the Moho Depth in the Slave Craton, Northwest Territories, Canada.
AU: * Aristimuno, J
EM: jasidore@connect.carleton.ca
AF: Carleton University, 1125 Colonel By Drive 2240 Herzberg building, Ottawa, ON K1S 5B6 Canada
AB: The Slave geological province, a relatively small area in the Canadian Northwest Territories incluiding the oldest rocks on Earth, is one of five cratons that form the Archean continental core of North America. Its tectonic evolution differs from the classical "life-raft model" proposed for most Archean terranes. In the Slave Craton, radiometric dating has revealed an east-west disparity between the various bedrock units exposed. The underlying lithospheric mantle, on the other hand, exhibits a NW-SE zonation, comprising three regions with distinctive geochemical and geophysical characteristics. This complex superposition suggests that crust-mantle coupling and stabilization occurred late in the orogenic development of the craton. Previous reflection and refraction studies in the Slave Craton have shown coincident reflection and refraction Moho depths at 33-35 km, which remain relatively constant beneath the Archean Slave Province and the Proterozoic domains located to the west. This is contrary to average values of crustal thickness from global compilations that would suggest a thicker Proterozoic crust of approximately 45 km. This observation implies that the Moho probably acted as a zone of detachment (mechanical boundary) during the Proterozoic Hottah-Slave collision. The Slave Craton has been extensively surveyed using seismic methods as part of the SNORCLE transect of the Canadian Lithoprobe project. The available data for this study are from a 600 km long seismic refraction/deep wide-angle reflection 2D profile acquired in 1997. In this paper, we present results from reprocessing both refraction and reflection seismic data. First, the refraction data is inverted and the resulting synthetic shot gathers are compared to observed data to validate the refraction velocity model. Then, the new velocity model is used as input to migrate the wide-angle reflection data. In addition, the depth to the Moho derived from inverted data will be compared to the interpreted Moho in the migrated reflection section. Finally, different sensitivity tests will be carried out to quantify the effect of varying the input velocity model on Moho depths.
DE: 0910 Data processing
SC: Seismology [S]
MN: Fall Meeting 2005