Nazca PlateThe Nazca plate is an oceanic tectonic plate in the southeastern Pacific Ocean that shares both convergent and divergent boundaries, corners multiple triple junctions, contains three seamount chains, overrides four hotspots and is responsible for the creation of the Andean orogeny (Figure 1). Over the last half-century, it has garnered much attention from the scientific and political community due to the hazards it poses to the populated west coast of South America. With oblique subduction underneath the South American plate, this active convergent margin is the longest subduction zone in the world, stretching 7500 km (Klotz et al., 2001) and produced the largest earthquake ever recoded on earth, the M 9.5 Valdivia earthquake (Kanamori & Cipar 1976). Read more...
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Caribbean Plate
The Caribbean Plate is centered amidst the Cocos, Panama, North Andes, South American, and North American Plates. Landmasses composing the Caribbean Plate include the majority of North Central America (Figure 1, #6,8,10) and the Greater Antilles (Figure 1, #1), as well as the Lesser Antilles (Figure 1, Antillean arc). In addition, the northern edge of the Caribbean plate is comprised of multiple microplates. The composition of rocks varies greatly between the tropical islands (Figure 1, #1,3,4,5,9) and Central America. The islands are thought to be a continuous volcanic arc chain of calc-alkaline composition (Nelson et al, 2011). Read more...
The Caribbean Plate is centered amidst the Cocos, Panama, North Andes, South American, and North American Plates. Landmasses composing the Caribbean Plate include the majority of North Central America (Figure 1, #6,8,10) and the Greater Antilles (Figure 1, #1), as well as the Lesser Antilles (Figure 1, Antillean arc). In addition, the northern edge of the Caribbean plate is comprised of multiple microplates. The composition of rocks varies greatly between the tropical islands (Figure 1, #1,3,4,5,9) and Central America. The islands are thought to be a continuous volcanic arc chain of calc-alkaline composition (Nelson et al, 2011). Read more...
Galapagos MicroplateThe Galapagos Microplate (GMP) is a tiny tectonic plate west of the Galapagos Islands in the eastern equatorial Pacific Ocean (Searle et al., 1985). It is famous for the intriguing bathymetry resulting from its triple junction, which occurs when three plate tectonic boundaries meet each other (Searle et al., 1985). As the site of the confluence of the Cocos-Nazca, Pacific-Nazca and Pacific-Cocos spreading centres, the GMP is characterized by a ridge-ridge-ridge (RRR) triple junction (Searle et al., 1985). Another notable feature of the GMP region is that it was the site of the discovery of the first black smoker and hydrothermal vent (Tao et al., 2011). Read more...
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Caribbean Microplates
Between the southern boundary of the North American plate and the northern boundary of the Caribbean plate lays a collection of microplates with extensive and interesting tectonic activity. Four microplates are defined in this region, the largest of which being the Gonâve microplate. The next largest plate is the Puerto Rico Virgin Islands microplate Two smaller microplates are also defined: the South Jamaica and North Hispaniola microplates. Geologic, geodetic and seismic observations were used to define these plates (Benford et al., 2012). Read more... |
The Gonâve microplate and its boundaries
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Suprasubduction Zone Microplates
The North Andean plate contains parts of Ecuador, Colombia, and Venezuela, naturally including the northern Andes. (Bird, 2003). The North Andean plate is mostly composed of sedimentary rocks from the Jurassic, Cretaceous, and Paleogene (i.e. spanning from 199.6 Ma to 23.02 Ma) that accumulated through accretion of sediments from the subducting Nazca plate (Ramos, 1999). A study by Cardona et al. (2011) found that there were five distinct tectonic episodes that resulted in the building of the northern Andes region: the collision of northern South America with the Caribbean (70 Ma), subduction related metamorphism and magmatism (65 Ma), the accumulation of a thick siliclastic accretionary wedge (60-58 Ma), arc magmatism (58-50 Ma), and regional uplift (<50 Ma). Read more...
The North Andean plate contains parts of Ecuador, Colombia, and Venezuela, naturally including the northern Andes. (Bird, 2003). The North Andean plate is mostly composed of sedimentary rocks from the Jurassic, Cretaceous, and Paleogene (i.e. spanning from 199.6 Ma to 23.02 Ma) that accumulated through accretion of sediments from the subducting Nazca plate (Ramos, 1999). A study by Cardona et al. (2011) found that there were five distinct tectonic episodes that resulted in the building of the northern Andes region: the collision of northern South America with the Caribbean (70 Ma), subduction related metamorphism and magmatism (65 Ma), the accumulation of a thick siliclastic accretionary wedge (60-58 Ma), arc magmatism (58-50 Ma), and regional uplift (<50 Ma). Read more...