Magnetism of the oceanic crust: Evidence from ophiolite complexes
The magnetic properties of six ophiolite complexes from around the world, ranging in age from Jurassic to Miocene, are presented. An emphasis is placed in our study on the petrologic and isotopic data from these ophiolite complexes in order to determine first whether the rock samples presently available represent the pristine ocean crust or whether they have been altered subaerially since their formation. Five of the ophiolites are found to be acceptable, and the conclusion is overwhelmingly in favor of a marine magnetic source layer that includes not only the pillow lavas but also the underlying dikes and gabbro. At the moment, however, our observations do not suggest that the magnetic contributions of the basaltic dikes should be overlooked in favor of gabbro. A second important conclusion is that nearly pure magnetite could indeed be a magnetic carrier which contributes to marine magnetic anomanies. It only awaits discovery by deeper ocean crustal penetration by future Deep Sea Drilling Project legs.
- Research Organization:
- Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455
- OSTI ID:
- 5242631
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 85:B7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OCEANIC CRUST
MAGNETISM
BASALT
GEOMAGNETIC FIELD
MAGNETITE
PETROLOGY
CHALCOGENIDES
EARTH CRUST
GEOLOGY
IGNEOUS ROCKS
IRON COMPOUNDS
IRON ORES
IRON OXIDES
MAGNETIC FIELDS
MINERALS
ORES
OXIDES
OXYGEN COMPOUNDS
ROCKS
TRANSITION ELEMENT COMPOUNDS
VOLCANIC ROCKS
580100* - Geology & Hydrology- (-1989)