Pacific Seamount volcanism in space and time

Hillier, J. K. (2007) Pacific Seamount volcanism in space and time. Geophysical Journal International, 168 (2). pp. 877-889. DOI 10.1111/j.1365

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Abstract

Seamounts constitute some of the most direct evidence about intraplate volcanism. As such, when seamounts formed and into which tectonic setting they erupted (i.e. on-ridge or off-ridge) are a useful reflection of how the properties of the lithosphere interact with magma generation in the fluid mantle beneath. Proportionately few seamounts are radiometrically dated however, and these tend to be recently active. In order to more representatively sample and better understand Pacific seamount volcanism this paper estimates the eruption ages (tvolc) of 2706 volcanoes via automated estimates of lithospheric strength. Lithospheric strength (GTRrel) is deduced from the ratio of gravity to topography above the summits of volcanoes, and is shown to correlate with seafloor age at the time of volcanic loading (Δt) at 61 sites where radiometric constraints upon Δt exist. A trend of fits data for these 61, and with seafloor age (tsf) known, can date the 2706 volcanoes; tvolc=tsf−Δt . Widespread recurrences of volcanism proximal to older features (e.g. the Cook-Austral alignment in French Polynesia) suggest that the lithosphere exerts a significant element of control upon the location of volcanism, and that magmatic throughput leaves the lithosphere more susceptible to the passage of future melts. Observations also prompt speculation that: the Tavara seamounts share morphological characteristics and isostatic compensation state with the Musicians, and probably formed similarly; the Easter Island chain may be a modern analogy to the Cross-Lines; a Musicians – South Hawaiian seamounts alignment may be deflecting the Hawaiian hotspot trace.

Item Type: Article
Uncontrolled Keywords: 2007 AREP 2007 P IA53
Subjects: 05 - Petrology - Igneous, Metamorphic and Volcanic Studies
02 - Geodynamics, Geophysics and Tectonics
Divisions: 02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title: Geophysical Journal International
Volume: 168
Page Range: pp. 877-889
Identification Number: 10.1111/j.1365
Depositing User: Sarah Humbert
Date Deposited: 16 Feb 2009 13:02
Last Modified: 23 Jul 2013 10:07
URI: http://eprints.esc.cam.ac.uk/id/eprint/375

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