Irregularly Shaped Seamounts Near the East Pacific Rise: Implications for Seamount Origin and Rise Axis Processes

  1. Barbara H. Keating,
  2. Patricia Fryer,
  3. Rodey Batiza and
  4. George W. Boehlert
  1. Daniel J. Fornari1,
  2. Rodey Batiza2 and
  3. James F. Allan2

Published Online: 18 MAR 2013

DOI: 10.1029/GM043p0035

Seamounts, Islands, and Atolls

Seamounts, Islands, and Atolls

How to Cite

Fornari, D. J., Batiza, R. and Allan, J. F. (1987) Irregularly Shaped Seamounts Near the East Pacific Rise: Implications for Seamount Origin and Rise Axis Processes, in Seamounts, Islands, and Atolls (eds B. H. Keating, P. Fryer, R. Batiza and G. W. Boehlert), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM043p0035

Author Information

  1. 1

    Lamont-Doherty Geological Observatory of Columbia University, Palisades, NY 10964

  2. 2

    Department of Geological Sciences, Northwestern University, Evanston, IL 60201

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1987

ISBN Information

Print ISBN: 9780875900681

Online ISBN: 9781118664209

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Keywords:

  • Seamounts;
  • Coral reefs and islands

Summary

We present new Seabeam and SeaMARC I data for small (<1 km high) volcanoes near the East Pacific Rise (EPR) that exhibit irregular (non-circular) plan-form shapes and whose surfaces are commonly cut by young faults and fissures. The structural control, petrology and close proximity of these irregular seamounts to the EPR strongly suggests a close genetic link between EPR processes and seamount formation and growth. We infer that their irregular shapes are due to early growth from eruptive conduits (fractures) that consist of intersecting sets of EPR parallel, EPR-perpendicular and oblique faults. Since many small volcanoes near the EPR have irregular shapes, we suggest that larger circular volcanoes may evolve from small irregular ones. This could occur if volcano shape is dominated by the geometry of their conduits in the early stages of growth (in turn controlled by local tectonic stress) but later their shapes are dominated by caldera collapse and gravitational stress within the edifice.