The emergence of a Galapagos shield volcano, Roca Redonda
Article Abstract:
Roca Redonda is the emergent peak of a submarine shield volcano that rises more than 3000 m from the adjacent seafloor. The volcano is considered representative of the most juvenile phase of Galapagos magmatism. An evolution model based on the geochemical data suggests the existence of a highly segregated chamber, with high-MgO basaltic magma overlying the pi-critic magma. It is also possible that the sequential batches of high-Mg magma disrupt and disaggregate a body of dunites and troctolites that had crystallized from slightly older batches of high-Mg magma.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1998
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On the emergence of plate tectonics
Article Abstract:
Plate tectonics may not have been dominant during the Archean because oceanic crust would have been more bouyant and difficult to subduct. Given higher mantle temperatures, the oceanic crust would be thicker and less amenable to subduction. Concurrent with faster convection, this would account for slow tectonic activity at that time. Subcrustal delamination or dripping and the existence of plumes may have provided an alternative mode to account for the rate of heat removal from the earth.
Publication Name: Geology
Subject: Earth sciences
ISSN: 0091-7613
Year: 1992
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Tertiary tectonics of the Sea of Okhotsk, Russia: far-field effects of the India-Eurasia collision
Article Abstract:
A new structural map of the western Sea of Okhotsk has been developed. The map was a result of a cooperative interpretation project between Shell International Petroleum Maatschappij B.V. and Dalmorneftegeifizika. The map, which is based on grids of multichannel seismic data and compiles structural contours on basement, provides new insights on the Tertiary deformation of Asia.
Publication Name: Tectonics
Subject: Earth sciences
ISSN: 0278-7407
Year: 1996
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