New explanation on the creation of the Cocos record
Deepwater drilling off the Costa Rican coast suggests that the Cocos Ridge was formed by a previously unknown hot spot beneath Cocos Island and an ancient spreading system. Hot spot formed. As part of the international deep-sea drilling program ODP (Ocean Drilling Program), Dr. Martin Meschede, private lecturer at the Geological Institute of the University of Tübingen, took part in a drilling trip with the research ship Joides Resolution. The results of this research trip, which led to a completely new explanation for the formation of the Cocos Plate off the coast of Costa Rica, were recently presented.
According to popular hypothesis, hot spots are the volcanic manifestations of mantle diapirs, hot material that rises in a narrow jet from the interior of the mantle (or even deeper), penetrates the lithosphere, and flows out at the surface. Hot spots explain volcanism within a plate (intraplate volcanism) and volcanic island chains. When a plate shifts, it takes the volcano over a hot spot with it, and it dies. A series of volcanoes can form in this way.
Previously it was assumed that a submarine ridge on the Cocos Plate, the Cocos Ridge, was formed by the Cocos Plate sliding over the Galapagos Hot Spot. However, the most recent investigations indicate that the Cocos Ridge is likely the product of a previously unknown hot spot beneath Cocos Island and an ancient spreading system. Spreading systems form when plates separate and bas alt rises. The fissure between the separating plates extends downward into the asthenosphere. Bas altic magmas rise into the gaps between the plates, flow out over the rifts, and form the oceanic ridges.
Since 1968, hundreds of boreholes with depths of up to several hundred meters have been drilled as part of the US-backed Deep Sea Drilling Program (DSDP) and its successor project, the international Ocean Drilling Program (ODP). The ODP is funded 60 percent by the American side, the remaining 40 percent is shared by research institutions in Japan, Canada, Australia, Germany, France, Great Britain and a consortium of the European Science Foundation.
Every two months, 25 geologists and geophysicists come together in an interesting part of the world's oceans to work together on the deep-sea drill ship Joides Resolution. The Joides Resolution is 143 meters long and has a derrick that is 61 meters high. From on board, several thousand meters of drill rods can be lowered onto the multisoil and then lowered another several thousand meters into the sediment and the underlying crust.
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