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Full-Text Articles in Physical Sciences and Mathematics
Pleistocene To Present North Andean “Escape”, James N. Kellogg, Obi Egbue
Pleistocene To Present North Andean “Escape”, James N. Kellogg, Obi Egbue
James N Kellogg
This study compiles 20 published field geologic estimates of displacement rates for the northern Andes, such as displaced glacial moraines and offset pyroclastic flow, and compares them to published Global Positioning System (GPS) measurements. Dated displacements compiled in this study were obtained from the Gulf of Guayaquil, Pallatanga, Chingual-la Sofia, and Cayambe-Afiladores-Sibundoy fault systems in Ecuador and southern Colombia and the Boconó fault system in Venezuela. Right-lateral slip estimates on the individual fault segments range from 2 mm/a to 10 mm/a. The mean estimated geologic slip rate for the last 86,000 years is 7.6 mm/a. This estimate is very similar …
Wide Plate Margin Deformation, Southern Central America And Northwestern South America, Casa Gps Observations, James Kellogg
Wide Plate Margin Deformation, Southern Central America And Northwestern South America, Casa Gps Observations, James Kellogg
James N Kellogg
Global Positioning System (GPS) data from southern Central America and northwestern South America were collected during 1991, 1994, 1996, and 1998 in Costa Rica, Panama, Ecuador, Colombia and Venezuela. These data reveal wide plate boundary deformation and escape tectonics occurring along an approximately 1400 km length of the North Andes; locking of the subducting Nazca plate and strain accumulation in the Ecuador-Colombia forearc; ongoing collision of the Panama arc and Colombia; and convergence of the Caribbean plate with Panama and South America. Elastic modeling of observed horizontal displacements in the Ecuador forearc is consistent with partial locking (50%) in the …