Oceanic lithosphere at the edge of a Cenozoic active continental margin (northwestern slope of Galicia Bank, Spain)
Malod, J.-A.; Murillas, J.; Kornprobst, J.; Boillot, G. (1993). Oceanic lithosphere at the edge of a Cenozoic active continental margin (northwestern slope of Galicia Bank, Spain). Tectonophysics 221(2): 195-206
In: Tectonophysics. ELSEVIER SCIENCE BV: New York; London; Amsterdam. ISSN 0040-1951; e-ISSN 1879-3266, more
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Keywords |
Crustal structure Earth sciences > Geology > Petrology Earth sciences > Geology > Tectonics > Plate tectonics Earth structure > Earth crust > Oceanic crust Earth structure > Lithosphere Geological time > Phanerozoic > Geological time > Cenozoic Topographic features > Submarine features > Continental margins ANE, Galicia Bank [Marine Regions] Marine/Coastal |
Authors | | Top |
- Malod, J.-A.
- Murillas, J.
- Kornprobst, J.
- Boillot, G.
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Abstract |
A basaltic seafloor was surveyed and sampled by the French submersible Nautile on the northwestern slope of the Galicia Bank (Spain); the morphology and petrology of the volcanic rocks indicate an oceanic crust, although rather enriched in incompatible elements. The radiometric age of the basalts (about 100 Ma) suggests that they were emplaced a short time after the onset of seafloor spreading in that part of the North Atlantic. This oceanic seafloor remained attached to the overriding Iberian Plate when the north and northwest passive Galicia margin was turned into an active margin in the Paleocene-Eocene. We consider this remnant basaltic seafloor to have been joined to the Galicia basement since the Mesozoic. Consequently, it cannot be interpreted as a wedge of oceanic lithosphere accreted to the Iberian plate as a result of Cenozoic subduction. |
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