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Crustal structure of the Cocos Ridge northeast of Cocos Island, Panamá Basin
Author(s) -
Walther Christian
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl014267
Subject(s) - geology , crust , oceanic crust , ridge , transect , hotspot (geology) , structural basin , mid ocean ridge , seismology , paleontology , tectonics , subduction , oceanography
The submarine Cocos ridge in the northwestern Panamá basin, Pacific ocean, is generally interpreted as the trace of the Galápagos hotspot. A 278 km long seismic wide‐angle transect was carried out across a comparatively narrow ridge segment, 150 km northeast of Cocos Island. The results indicate a huge thickened crust, where crustal thickening is mainly achieved by the lower crust, which makes up 75% of the crustal thickness and is tripled compared to normal oceanic lower crust. The velocities are comparable to normal lower crust and suggest no differences to a gabbroic composition. The Moho deepens from 10 to 18 km depth below the ridge. Similarities to other hotspot related oceanic ridges and plateaus with massive lower crusts and velocities below 7.4 km/s suggest the formation of this Cocos ridge segment near or at the plate boundary.