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True polar wander, a supercontinental legacy

Evans, David A. (1998) True polar wander, a supercontinental legacy. Earth and Planetary Science Letters, 157 (1-2). pp. 1-8. ISSN 0012-821X. http://resolver.caltech.edu/CaltechAUTHORS:20180424-092244369

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Abstract

Paleomagnetically determined apparent polar wander (APW) paths should contain components of individual plate motions as well as true polar wander (TPW), the uniform motion of the mantle relative to the spin axis. Quantifying the TPW component for pre-Mesozoic time is hampered by the lack of a representative from the mantle reference frame; nevertheless, TPW can be estimated if all or most of the continents show similar APW paths for a given period of time. Two such estimates have been proposed recently for the early Paleozoic. Plotted relative to Gondwanaland, which may have been drifting over the mantle slowly enough to constitute an approximate mantle reference frame, these TPW swaths are oscillatory and nearly coaxial. A long-lived and stable prolateness of Earth's non-hydrostatic geoid between Cambrian and Devonian time could produce such a pattern of TPW. Similarly oscillatory APW paths exist for the late Neoproterozoic cratons, perhaps indicating TPW about the same long-lived axis during that earlier interval as well. This long-lived prolate axis of Earth' non-hydrostatic figure, representing a stable configuration of mantle mass anomalies, may have been inherited from the vanished Rodinia supercontinent in the same way that the present non-hydrostatic geoid's prolate axis may be a legacy of Mesozoic Pangea and its peripheral subduction zones. These geoidal legacies may endure for several hundred Myr after supercontinental fragmentation, perhaps indicating a characteristic lag time between two distinct geological phenomena: global-scale surface tectonics recorded by the growth and disassembly of supercontinents; and deep mantle convective structure indicated by the long-term record of TPW.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1016/S0012-821X(98)00031-4DOIArticle
https://www.sciencedirect.com/science/article/pii/S0012821X98000314PublisherArticle
Additional Information:© 1998 Elsevier Science B.V. Received 11 November 1997, Revised 5 February 1998, Accepted 11 February 1998, Available online 1 July 1998. I thank D.L. Anderson, M. Billen, R.G. Gordon, M. Gurnis, P.F. Hoffman, J.L. Kirschvink, R.J. O'Connell, M.A. Richards, D.L. Stevenson, and R. Van der Yoo for stimulating discussions. Some of the figures were created using the GMAP application administered by T.H. Torsvik. D.M. Jurdy and two anonymous reviewers of the manuscript prompted important clarifications. This work is supported by NSF Grant EAR94-18523 and an NSF Graduate Research Fellowship. [RV]
Funders:
Funding AgencyGrant Number
NSFEAR94-18523
NSF Graduate Research FellowshipUNSPECIFIED
Subject Keywords:geodynamics; polar wandering; Gondwana; paleomagnetism; geoid; mantle; convection
Record Number:CaltechAUTHORS:20180424-092244369
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20180424-092244369
Official Citation:David A. Evans, True polar wander, a supercontinental legacy, Earth and Planetary Science Letters, Volume 157, Issues 1–2, 1998, Pages 1-8, ISSN 0012-821X, https://doi.org/10.1016/S0012-821X(98)00031-4. (http://www.sciencedirect.com/science/article/pii/S0012821X98000314)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86020
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:25 Apr 2018 17:44
Last Modified:25 Apr 2018 17:44

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