Neogene Patagonian plateau lavas: continental magmas associated with ridge collision at the Chile Triple Junction
Article Abstract:
Trace element and isotopic data establish a link between the distribution of Neogene Patagonian plateau lavas southeast of the Chile Triple Junction and the collision of Chile Ridge segments with the Chile Trench at about 6 and 12 Ma. A migrating slab window model relates the tholeiitic, main-plateau lavas to large-volume, high-percentage partial melts generated by the interaction of upwelling asthenosphere with metasomatized H2O-bearing continental lithosphere. An ocean island basalt (OIB)-like source region is explained by entrainment of weak plume in an OIB-like asthenosphere.
Publication Name: Tectonics
Subject: Earth sciences
ISSN: 0278-7407
Year: 1997
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Large-scale right-slip displacement on the East San Francisco Bay Region fault system, California: implications for location of late Miocene to Pliocene Pacific plate boundary
Article Abstract:
The East San Francisco Bay Region (ESFBR) fault system has accommodated almost 160 to 170 kms of right slip due to the movement of two belts of younging volcanic rocks. The overlap of ages in the belts indicates that they were originally formed from one younging trend. A slab window probably opened below the North American plate near the San Andreas transform. The displacements of volcanic rocks of Miocene and younger origins probably occurred across the ESFBR fault system in which a large slip was accommodated between 8 and 6 Ma.
Publication Name: Tectonics
Subject: Earth sciences
ISSN: 0278-7407
Year: 1996
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Uplifted Neogene margin, southernmost Cascadia-Mendocino triple junction region, California
Article Abstract:
The interaction of southern Juan de Fuca (Gorda) plate with older North American and Pacific plates raises and bends northward a Neogene accretionary complex. The complex is towards the north of the Mendocino triple junction. Tectonic events occur along with these plate interactions. Miocene to Pliocene deposits of southern Cascadia forearc mix with Franciscan Complex accretionary terranes. Analysis of the nature and structure of False Cape terrane is given.
Publication Name: Tectonics
Subject: Earth sciences
ISSN: 0278-7407
Year: 1995
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