Imperial College London
Alternate

Dr Ian Bastow

Faculty of Engineering, Department of Earth Science & Engineering

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 2974i.bastow Website

 
 
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Location

 

4.45Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Boyce:2019:10.1016/j.epsl.2019.115763,
author = {Boyce, A and Bastow, I and Golos, E and Rondenay, S and Burdick, S and Van, der Hilst R},
doi = {10.1016/j.epsl.2019.115763},
journal = {Earth and Planetary Science Letters},
title = {Variable modification of continental lithosphere during the Proterozoic Grenville Orogeny: evidence from teleseismic P-wave tomography},
url = {http://dx.doi.org/10.1016/j.epsl.2019.115763},
volume = {525},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Cratons, the ancient cores of the continents, have survived thermal and mechanical erosion over multiple Wilson cycles, but the ability of their margins to withstand modification during continental convergence is debated. The Proterozoic Grenville orogeny operated for ≥300Myr along the eastern edge of the proto-North American continent Laurentia, whose age varied north-to-south from ∼1.5−0.25Gyr at the time of collision. The preserved Grenville Province, west of the Appalachian terranes, has remained largely tectonically quiescent since its formation. Thick, cool, mantle lithosphere that underlies these Proterozoic regions is typically identified by elevated seismic velocities but lithospheric modification by fluid/melt-derived metasomatic enrichment above a subduction zone, can lead to a reduction in VP with little effect on VS and density. Absolute P wavespeed constraints are therefore a vital complement to existing S-wave tomographic models of North America to investigate craton edge modification mechanisms in the Grenville orogen.New P-wave tomographic imaging of the North American continent, which benefits from recent developments in arrival-time processing of regional network deployments from the Canadian shield, reveals along strike wavespeed variation in the Grenville orogen. In the north, high seismic wavespeeds (to depths of 250km) extend eastwards, from the Archean core of North America to beneath the Canadian Grenville Province. In contrast, below the southern U.S., high lithospheric wavespeeds are restricted to west of the Grenville Province, in particular at depths less than 150km. We argue that subduction-derived metasomatism beneath eastern Laurentia modified the southern Grenville, prior to thermal stabilization and perhaps mantle keel formation. Beneath the northern Grenville, the thick, depleted Laurentian lithosphere resisted extensive metasomatism. Along strike age differences in Grenvillian terranes and their resulting metasomatic
AU  - Boyce,A
AU  - Bastow,I
AU  - Golos,E
AU  - Rondenay,S
AU  - Burdick,S
AU  - Van,der Hilst R
DO  - 10.1016/j.epsl.2019.115763
PY  - 2019///
SN  - 0012-821X
TI  - Variable modification of continental lithosphere during the Proterozoic Grenville Orogeny: evidence from teleseismic P-wave tomography
T2  - Earth and Planetary Science Letters
UR  - http://dx.doi.org/10.1016/j.epsl.2019.115763
UR  - http://hdl.handle.net/10044/1/72379
VL  - 525
ER  -
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