Seismic velocities and composition of the Canadian crust
It has been suggested that processes driving crustal formation in the Archean and Proterozoic were dissimilar and produced crusts with unique bulk properties and average thicknesses. The calibration of models based on evolving mantle fractionation or mantle convection style require accurate estim...
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| Language: | English |
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University of British Columbia
2014
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| Online Access: | http://hdl.handle.net/2429/46687 |
| Summary: | It has been suggested that processes driving crustal formation in the Archean and Proterozoic
were dissimilar and produced crusts with unique bulk properties and average thicknesses.
The calibration of models based on evolving mantle fractionation or mantle convection style
require accurate estimates of the geological and geophysical properties of crustal provinces
to better constrain the details of crustal formation. Fifteen years of publicly accessible
teleseismic data from all available Canadian seismic stations are binned in horizontal slowness
and deconvolved into receiver functions. We apply a stacking method to retrieve estimates of
the bulk crustal velocity ratio V P /V S and thickness H from these data under the assumption
of locally 1-D structure. We also investigate modifications to this approach that can allow
discrimination of V S and V P under certain conditions. Bootstrap error analysis is performed
for each station dataset and subsets of these measurements are compared with results for
matching stations from previous studies. Analysis of results in conjunction with additional
velocity estimates from active source seismic studies and a seismic property database affords
improved constraints on bulk geological composition of the Canadian landmass that are used
to evaluate competing models of crustal formation. |
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