New Google Earth data set: Galapagos "hotspot" dates: present & restored.
Ar/Ar and K/Ar dates from Galapagos "hotspot" region.
Two renderings: (1) Present day sample locations and (2) restored locations. (Vertical dimension: Age (Ma) multiplied by 5000 m.)
Restored locations: Rotated back to Hawaiian hotspot reference frame for inferred crystallization age. Hawaiian-Pacific model: Raymond et al. (2000, corrected). Relative plate reconstructions: Pilger (2007 compilation). Interpolated using splined pseudovectors (method of Pilger, 2003). For dates older than 9 Ma from Malpelo Ridge and offshore Panama east of 82 degrees W longitude, it was assumed that they formed on the Cocos plate and were transferred from the Cocos to the Nazca plate at 9 Ma.
Note that oldest dates from Cocos, Carnegie, and Malpelo Ridges cluster in a circle with diameter on the order of 500-600 km.
Sources: White et al (1993), O'Connor et al (2007).
Monday, December 17, 2007
Tuesday, December 11, 2007
Google Earth: Isotopic Dates from Global "Hotspot" Traces -- Galapagos
I've added an additional data set for the Galapagos "hotspot" to an existing post:
Isotopic Dates from Global "Hotspot" Traces. Scroll to #1070646 - 12/11/07 11:34 AM.
The new data are from: O'Connor J. M., Stoffers, P., Wijbrans, J. R., and Worthington, T. J., 2007, Migration of widespread long-lived volcanism across the Galápagos Volcanic Province: Evidence for a broad hotspot melting anomaly? Earth and Planetary Science Letters, 263, 339-354, doi:10.1016/j.epsl.2007.09.007.In this kmz there is also a folder with K/AR dates from: W.M. White, A.R. McBirney and R.A. Duncan, 1993, Petrology and geochemistry of the Galápagos Islands: portrait of a pathological mantle plume, Journal of Geophysical Research, 98 , 19,533–19,563.
Isotopic Dates from Global "Hotspot" Traces. Scroll to #1070646 - 12/11/07 11:34 AM.
The new data are from: O'Connor J. M., Stoffers, P., Wijbrans, J. R., and Worthington, T. J., 2007, Migration of widespread long-lived volcanism across the Galápagos Volcanic Province: Evidence for a broad hotspot melting anomaly? Earth and Planetary Science Letters, 263, 339-354, doi:10.1016/j.epsl.2007.09.007.In this kmz there is also a folder with K/AR dates from: W.M. White, A.R. McBirney and R.A. Duncan, 1993, Petrology and geochemistry of the Galápagos Islands: portrait of a pathological mantle plume, Journal of Geophysical Research, 98 , 19,533–19,563.
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