Abstract
The Farallon plate was an enormous oceanic plate located west of the Americas during the Cenozoic and Mesozoic eras. This plate has now been almost completely subducted beneath the American plates. In the Northern Hemisphere, the Farallon plate broke up to form a number of independent smaller plates1–3 when its western edge approached the North American plate. Here we present a tomographic image of the subducted trailing fragments of the Farallon plate in the upper mantle beneath the western margin of North America. The relatively cold, subducted fragments appear as an intricate region of high seismic S-wave velocity. Comparison of the structure of this high-velocity region with tectonic plate reconstructions and volcanic records enables us to identify individual fragments of the subducted Farallon plate and thus reconstruct qualitatively the kinematic evolution of the Farallon slab in the upper mantle beneath North America.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Atwater, T. Implications of plate tectonics for the Cenozoic tectonic evolution of western North America. Geol. Soc. Am. Bull. 81, 3513–3536 (1970).
Atwater, T. in The Geology of North America Vol. N, The Eastern Pacific Ocean and Hawaii (eds Winterer, E. L., Hussong, D. M. & Decker, R. W.) 21–72 (Geol. Soc. Am., Boulder, CO, 1989).
Stock, J. M. & Lee, J. Do microplates in subduction zones leave a geological record? Tectonics 13, 1472–1487 (1994).
Engebretson, D. C., Cox, A. & Gordon, A. G. Relative Motions Between Oceanic and Continental Plates in the Pacific Basin (Spec. Pap. 206, Geol. Soc. Am., Boulder, CO, 1985).
Stock, J. & Molnar, P. Uncertainties and implications of the Late Cretaceous and Tertiary position of North America relative to the Farallon, Kula and Pacific plates. Tectonics 7, 1339–1384 (1988).
Severinghaus, J. & Atwater, T. in Basin and Range Extensional Tectonics Near the Latitude of Las Vegas, Nevada (ed. Warnicke, B. P.) 1–22 (Mem. 176, Geol. Soc. Am., Boulder, CO, 1990).
Lipman, P. W., Protska, H. J. & Christiansen, R. L. Cenozoic volcanism and plate-tectonic evolution of the Western United States. I. Early and Middle Cenozic. Phil. Trans. R. Soc. Lond. A 271, 217–248 (1972).
Lipman, P. W. in The Geology of North America Vol. G-3, (eds Burchfiel, B. C., Lipman, P. W. & Zoback, M. L.) 481–514 (1992).
Cross, T. A. in Foreland Basins (eds Allen, P. A. & Homewood, P.) 15–39 (Spec. Publ. 8, Int. Assoc. Sedimentologists, Blackwell Scientific, Oxford, 1986).
Solomon, S. C. & Butler, R. G. Prospecting for dead slabs. Earth Planet. Sci. Lett. 21, 421–430 (1974).
Romanowicz, B. Large scale three dimensional P velocity strucutre beneath the western U.S. and the lost Farallon plate. Geophys. Res. Lett. 7, 345–348 (1980).
Grand, S. P. Mantle shear structure beneath the Americas and surrounding oceans. J. Geophys Res. 99, 11591–11621 (1994).
Van der Hilst, R. D., Widiyantoro, S. & Engdahl, E. R. Evidence for deep mantle circulation from global tomography. Nature (in the press).
Nolet, G. Partitioned waveform inversion and two-dimensional structure under the network of autonomously recording seismographs. J. Geophys. Res. 95, 8499–8512 (1990).
Zielhuis, A. & Nolet, G. Shear-wave velocity variations in the upper mantle beneath central Europe. Geophys. J. Int. 117, 695–715 (1994).
Davies, J. H. & Stevenson, D. J. Physical model of source region of subduction zone volcanics. J. Geophys. Res. 97, 2037–2070 (1992).
Duffy, T. S. & Anderson, D. L. Seismic velocities in mantle minerals and the mineralogy of the upper mantle. J. Geophys. Res. 94, 1895–1912 (1989).
Bostock, M. G. & VanDecar, J. C. Upper mantle structure of the northern Cascadia subduction zone. Can. J. Earth Sci. 32, 1–12 (1995).
Pardo, M. & Suárez, G. Shape of the subducted Rivera and Cocos plates in southern Mexico: seismic and tectonic implications. J. Geophys. Res. 100, 12357–12394 (1995).
Dickinson, W. R. & Snyder, W. S. Geometry of subducted slabs related to San Andreas transform. J. Geol. 87, 609–627 (1979).
Dickinson, W. R. Tectonic implications of Cenozoic volcanism in coastal California. Bull. Geol. Soc. Am. (in the press).
Christiansen, R. L. & Lipman, P. W. Cenozoic volcanism and plate-tectonic evolution of the western United States: II. late Cenozoic. Phil Trans. R. Soc. Lond. A 271, 249–284 (1972).
Christiansen, R. L. & McKee, E. H. Cenozoic Tectonics and Regional Geophysics of the Western Cordillera (eds Smith, R. B. & Eaton, G. P.) 283–311 (Mem. 152, Geol. Soc. Am., Boulder, CO, 1978).
Humphreys, E. D. Post-Laramide removal of the Farallon slab, western United States. Geology 23, 987–990 (1995).
Mora-Alvarez, G. & McDowell, F. W. Miocene Volcanism During Late Subduction and Early Rifting in the Sierra Santa Ursula of Western Sonora, Mexico (Spec. Pap., Geol. Soc. Am., in the press).
Van der Lee, S. & Nolet, G. The upper-mantle S-velocity structure of North America. J. Geophys. Res. (in the press).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
van der Lee, S., Nolet, G. Seismic image of the subducted trailing fragments of the Farallon plate. Nature 386, 266–269 (1997). https://doi.org/10.1038/386266a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/386266a0
