OI Cocos Island, Cape Verde Island, Iceland
Item
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Title
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OI Cocos Island, Cape Verde Island, Iceland
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Description
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Compare and Contrasting information regarding tectonic setting, landforms, magma generating processes and geochemistry of the Cocos Island, Cape Verde Island and Iceland.
The three OI we had were the Cocos Island, Cape Verde and Iceland (marked in red respectively from west to east). The Cocos Islands are located on an intraplate margin in the middle of the Cocos plate in the Pacific Ocean. The Cape Verde Islands are located to the east of the African Continental margin on an intraplate tectonic setting. They were formed due to hotspot volcanism with magma originating from the core mantle boundary. Iceland is located on a divergent boundary between the North American plate and Eurasian plate and also above the Iceland Plume hotspot. Both Cocos Islands and Cape Verde and located on an intraplate setting.
The Cocos Islands and Cape Verde both are semi-linear due to the lithosphere moving over the hotspot. Iceland on the other hand is a singular island. The Cocos ridge is ~1000 km long and ~200 km wide and has elevations peaking at 1000 m. The landforms were formed from a submarine volcano. Cape Verde consists of shallow shield volcanos. There are over 150 volcanos on Iceland but only about 30 actives ones which are located on the active rift margins.
Magma is generated in ocean island settings through mantle plumes that originate from the core-mantle boundary. In this respect, all ocean islands are similar. However, not all ocean islands are the same. The Cocos Islands and the Cape Verde Islands are similar because they are both in intraplate settings. This means that they are located within the margins of an oceanic plate. Iceland has unusual circomstances because the mid-Atlantic ridge runs through the landmass. In addition to the ridge, a hotspot also influences the spreading center on Iceland. This creates enriched-mid ocean ridge basalts, as opposed to normal ocean island basalts that come from locations like the Cocos Islands and the Cape Verde Islands.
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Creator
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Hana Isihara
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Contributor
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Claire Kojaian, Ryan Sanders
Locality Map