Hudson Bay Lithospheric Experiment (HUBLE)

Abstract
We are carrying out a broadband seismological study of the Hudson Bay region of northern Canada with the view to understanding better the reasons for the Bay’s existence, and the nature of the tectonic processes that shaped the Canadian shield during the Precambrian. The network consists of 10 CMG3T G¨uralp instruments with a combination of Taurus and DCM data loggers recording data at 40Hz in both remote (solar powered) and community (mains powered) locations. Our work is being carried out in conjunction with the Geological Survey of Canada who are providing significant logistical and financial support beyond the scope of the original NERC-funded proposal. To date, data quality has been excellent, with percentage recovery good except during the long Canadian winters when stations powered down. A number of publications have already resulted from analysis of the new dataset showing that: (i) the lithosphere in the region has retained a ∼1.8 Ga fossil fabric, providing strong evidence that modern-day-style plate tectonics was in operation by Paleoproterozoic times (the Trans Hudson Orogen). (ii) Crustal formation of the Canadian Shield likely evolved from one characterised by a hot ductile regime during the Paleoarchean, to one more closely resembling modern-day-style plate tectonics by the Paleoproterozoic. (iii) Crustal stretching, not a mantle down-welling, eclogitised lower-crust, or incomplete glacial rebound are likely responsible for the presence of the Bay.
Full Report
Selected external publications resulting from this GEF loan
- Liddell, M.V., Bastow, I., Rawlinson, N., Darbyshire, F., Gilligan, A. and Watson, E., 2018, Precambrian Plate Tectonics in Northern Hudson Bay: Evidence From P and S Wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival-Time Data Sets, Journal of Geophysical Research: Solid Earth, 123(7), p5690-5709, doi: 10.1029/2018JB015473
- Boyce, A., Bastow, I.D., Golos, E.M., Rondenay, S., Burdick, S. and Van der Hilst, R.D., 2019, Variable modification of continental lithosphere during the Proterozoic Grenville orogeny: Evidence from teleseismic P-wave tomography, Earth and Planetary Science Letters, 525, p115763, doi: 10.1016/j.epsl.2019.115763
- Ogden, C.S., Bastow, I.D., Gilligan, A. and Rondenay, S., 2019, A reappraisal of the H–κ stacking technique: implications for global crustal structure, Geophysical Journal International, 219(3), p1491-1513, doi: 10.1093/gji/ggz364
- Bastow, I.D., Thompson, D., Wookey, J., Kendall, J.-M., Helffrich, G., Snyder, D., Eaton, E. and Darbyshire, F., 2010, Precambrian plate tectonics: Seismic evidence from Northern Hudson Bay, Geology, 39(1), pp91-94, doi: 10.1130/G31396.1
- Thompson, D., Bastow, I.D., Kendall, J.-M., Helffrich, G., Wookey, J., Snyder, D. and Eaton, D., 2010, Precambrian crustal evolution: Seismic constraints from the Canadian shield, Earth and Planetary Science Letters, 297(3-4), pp655-666, doi: 10.1016/j.epsl.2010.07.021
- Bastow, I., Thompson, D., Wookey, J., Kendall, J.M., Helffrich, G., Snyder, D., Eaton, D. and Darbyshire, F., 2011, Precambrian plate tectonics: Seismic evidence from northern Hudson Bay, Canada, Geology, 39, pp91-94, doi: 10.1130/G31396.1
- Bastow, I.D., Kendall, J.M., Brisbourne, A.M., Snyder, D.B., Thompson, D., Hawthorn, D., Helffrich, G.R., Wookey, J., Horleston, A. and Eaton, D., 2011, The Hudson Bay Lithospheric Experiment, Astronomy and Geophysics, pp6.21-6.24, doi: doi:10.1111/j.1468-4004.2011.52621.x
- Pawlak, A., Eaton, D., Bastow, I.D., Kendall, J.-M., Helffrich, G., Wookey, J. and Snyder, D., 2011, Crustal structure beneath Hudson Bay from ambient-noise tomography: Implications for basin formation, Geophysical Journal International, 184(1), pp65-82, doi: 10.1111/j.1365-246X.2010.04828.x
- Thompson, D., Helffrich, G., Bastow, I., Kendall, J.M., Wookey, J., Eaton, D. and Snyder, D., 2011, Implications of a simple mantle transition zone beneath cratonic North America, Earth and Planetary Science Letters, 312, pp28-36
- Gilligan, A., Bastow, I.D. and Darbyshire, F.A., 2016, Seismological structure of the 1.8 Ga Trans-Hudson Orogen of North America, Geochemistry, Geophysics, Geosystems, 17(6), p2421-2433, doi: 10.1002/2016GC006419
