Control of regional sea level by surface uplift and subsidence caused by magmatic underplating of Earth's crust
- 1Laboratoire de Géosciences Marines, Institut de Physique du Globe de Paris, 4 Place Jussieu, 75005 Paris, France
- 2Bullard Laboratories, Department of Earth Sciences, Madingley Road, Cambridge CB3 0EZ, UK
Abstract
Magmatic underplating of the crust is a common feature of major basalt provinces. The emplacement of magma within the lithosphere leads to surface uplift, with a magnitude of the order of 10% of the thickness of the underplated material. The composition of associated igneous rock samples suggests that much of the underplated material is made of gabbro. This gabbro is denser than the magma from which it crystallizes, so uplift of Earth's surface caused by the emplacement of magma at the crust-mantle boundary must be followed by subsidence as the magma solidifies. This subsidence is equal to approximately half the original uplift and takes place within ∼0.1 m.y. of injection of the magma. The association of magmatic underplating with surface uplift followed by subsidence provides a mechanism for changes of sea level, including previously unexplained episodic highstands of sea level.
Footnotes
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↵GSA Data Repository item 2002079, Thermodynamic properties used in modeling including rock densities, specific heat capacities, and melting range, is available on request from Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301-9140, USA, editinggeosociety.org, or at http://www.geosociety.org/pubs/ft2002.htm.
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- Accepted April 12, 2002.
- Received December 12, 2001.
- Revision received April 2, 2002.
- Geological Society of America
