Upper mantle beneath a young oceanic rift: Peridotites from the island of Zabargad (Red Sea)
Bonatti, E.; Hamlyn, P.R.; Ottonello, G. (1981). Upper mantle beneath a young oceanic rift: Peridotites from the island of Zabargad (Red Sea). Geology (Boulder Colo.) 9(10): 474-479
In: Geology. Geological Society of America: Boulder. ISSN 0091-7613; e-ISSN 1943-2682, more
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| Keywords |
Biological development > Embryonic development
Earth structure > Basement rock
Earth structure > Earth mantle > Upper mantle
Earth structure > Lithosphere
Mineralogy
Peridotite
Rare earths
Rift zones
Rocks > Igneous rocks > Ultramafic rocks > Ophiolites
Marine/Coastal |
| Authors | | Top |
- Bonatti, E.
- Hamlyn, P.R.
- Ottonello, G.
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| Abstract |
Information on the nature of the upper mantle in a young rift zone with lithosphere transitional from continental to oceanic was obtained from the island of Zabargad, probably an uplifted fragment of Red Sea lithosphere. The island exposes exceptionally fresh, mantle-derived peridotite (spinel Iherzolite) bodies. The mineralogy and major-element, rare-earth element, and mineral chemistry of the spinel Iherzolites suggest that they equilibrated last at depth 30 km in the mantle and that they have oceanic rather than continental affinity. It is unlikely that the Zabargad ultramafics are part of a late Precambrian-early Paleozoic ophiolite, as found elsewhere in circum-Red Sea regions; rather, they were uplifted probably in connection with the development of the Red Sea Rift. The Zabargad peridotites are in tectonic contact with continental metamorphic basement rocks; it appears, therefore, that regions of an embryonic rift such as the Red Sea can be covered with continental-type crust but be underlain by an upper mantle having already oceanic affinities. |
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