Subduction system and flat slab beneath the Eastern Cordillera of Colombia

Claudio Chiarabba; Pasquale De Gori; Claudio Faccenna; Fabio Speranza; Danilo Seccia; Viviana Dionicio; Germán A. Prieto

doi:10.1002/2015GC006048

Subduction system and flat slab beneath the Eastern Cordillera of Colombia

Claudio Chiarabba, Pasquale De Gori, Claudio Faccenna, Fabio Speranza, Danilo Seccia, Viviana Dionicio, Germán A. Prieto

Producción científica: Contribución a una revista › Artículo › revisión exhaustiva

59 Citas (Scopus)

Resumen

La sismicidad en el extremo norte de la subducción de Nazca se difunde sobre una amplia área que contiene la misteriosa característica sísmica conocida como el nido de Bucaramanga. Reubicamos cerca de 5000 terremotos registrados por la red sísmica nacional colombiana y producimos el primer modelo de velocidad tridimensional del área para definir la geometría de la subducción de la litósfera por debajo de los Andes colombianos. Encontramos heterogeneidades de velocidad lateral y un desplazamiento abrupto de la zona Wadati-Benioff a 5°N indicando que la placa de Nazca está segmentada por un desgarro de la losa E-W, que separa un segmento más escarpado de Nazca al sur de una subducción plana al norte. La losa plana de Nazca se extiende hacia el este por unos 400 km, antes de que el buzamiento aumente a ∼° debajo de la Cordillera Oriental, donde produce el nido de Bucaramanga. Explicamos este desconcertante lugar de sismicidad de profundidad intermedia ubicado debajo de la Cordillera Oriental de Colombia como debido a una deshidratación masiva y a la eclogitización de una corteza oceánica engrosada. Relacionamos la geometría de la subducción plana con la entrada de la zanja en ca. 10 Ma de una gruesa y boyante corteza oceánica, probablemente una cresta volcánica, que produce un alto acoplamiento con la placa de invalidación. La subducción de la placa sub-horizontal es consistente con la desaparición abrupta del volcanismo en los Andes de Sudamérica en latitudes > 5°N.

Idioma original	Inglés estadounidense
Páginas (desde-hasta)	16-27
Número de páginas	12
Publicación	Geochemistry, Geophysics, Geosystems
Volumen	17
N.º	1
DOI	https://doi.org/10.1002/2015GC006048
Estado	Publicada - ene. 1 2016
Publicado de forma externa	Sí

Acceder al documento

10.1002/2015GC006048

Citar esto

@article{2ecb6ce35e1544fcbb6d36dd6164869b,

title = "Subduction system and flat slab beneath the Eastern Cordillera of Colombia",

abstract = "Seismicity at the northern terminus of the Nazca subduction is diffused over a wide area containing the puzzling seismic feature known as the Bucaramanga nest. We relocate about 5000 earthquakes recorded by the Colombian national seismic network and produce the first 3-D velocity model of the area to define the geometry of the lithosphere subducting below the Colombian Andes. We found lateral velocity heterogeneities and an abrupt offset of the Wadati-Benioff zone at 5°N indicating that the Nazca plate is segmented by an E-W slab tear, that separates a steeper Nazca segment to the south from a flat subduction to the north. The flat Nazca slab extends eastward for about 400 km, before dip increases to 50° beneath the Eastern Cordillera, where it yields the Bucaramanga nest. We explain this puzzling locus of intermediate-depth seismicity located beneath the Eastern Cordillera of Colombia as due to a massive dehydration and eclogitization of a thickened oceanic crust. We relate the flat subducting geometry to the entrance at the trench at ca. 10 Ma of a thick - buoyant oceanic crust, likely a volcanic ridge, producing a high coupling with the overriding plate. Sub-horizontal plate subduction is consistent with the abrupt disappearance of volcanism in the Andes of South America at latitudes > 5°N.",

author = "Claudio Chiarabba and {De Gori}, Pasquale and Claudio Faccenna and Fabio Speranza and Danilo Seccia and Viviana Dionicio and Prieto, {Germ{\'a}n A.}",

year = "2016",

month = jan,

day = "1",

doi = "10.1002/2015GC006048",

language = "English (US)",

volume = "17",

pages = "16--27",

journal = "Geochemistry, Geophysics, Geosystems",

issn = "1525-2027",

publisher = "American Geophysical Union",

number = "1",

}

TY - JOUR

T1 - Subduction system and flat slab beneath the Eastern Cordillera of Colombia

AU - Chiarabba, Claudio

AU - De Gori, Pasquale

AU - Faccenna, Claudio

AU - Speranza, Fabio

AU - Seccia, Danilo

AU - Dionicio, Viviana

AU - Prieto, Germán A.

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Seismicity at the northern terminus of the Nazca subduction is diffused over a wide area containing the puzzling seismic feature known as the Bucaramanga nest. We relocate about 5000 earthquakes recorded by the Colombian national seismic network and produce the first 3-D velocity model of the area to define the geometry of the lithosphere subducting below the Colombian Andes. We found lateral velocity heterogeneities and an abrupt offset of the Wadati-Benioff zone at 5°N indicating that the Nazca plate is segmented by an E-W slab tear, that separates a steeper Nazca segment to the south from a flat subduction to the north. The flat Nazca slab extends eastward for about 400 km, before dip increases to 50° beneath the Eastern Cordillera, where it yields the Bucaramanga nest. We explain this puzzling locus of intermediate-depth seismicity located beneath the Eastern Cordillera of Colombia as due to a massive dehydration and eclogitization of a thickened oceanic crust. We relate the flat subducting geometry to the entrance at the trench at ca. 10 Ma of a thick - buoyant oceanic crust, likely a volcanic ridge, producing a high coupling with the overriding plate. Sub-horizontal plate subduction is consistent with the abrupt disappearance of volcanism in the Andes of South America at latitudes > 5°N.

AB - Seismicity at the northern terminus of the Nazca subduction is diffused over a wide area containing the puzzling seismic feature known as the Bucaramanga nest. We relocate about 5000 earthquakes recorded by the Colombian national seismic network and produce the first 3-D velocity model of the area to define the geometry of the lithosphere subducting below the Colombian Andes. We found lateral velocity heterogeneities and an abrupt offset of the Wadati-Benioff zone at 5°N indicating that the Nazca plate is segmented by an E-W slab tear, that separates a steeper Nazca segment to the south from a flat subduction to the north. The flat Nazca slab extends eastward for about 400 km, before dip increases to 50° beneath the Eastern Cordillera, where it yields the Bucaramanga nest. We explain this puzzling locus of intermediate-depth seismicity located beneath the Eastern Cordillera of Colombia as due to a massive dehydration and eclogitization of a thickened oceanic crust. We relate the flat subducting geometry to the entrance at the trench at ca. 10 Ma of a thick - buoyant oceanic crust, likely a volcanic ridge, producing a high coupling with the overriding plate. Sub-horizontal plate subduction is consistent with the abrupt disappearance of volcanism in the Andes of South America at latitudes > 5°N.

U2 - 10.1002/2015GC006048

DO - 10.1002/2015GC006048

M3 - Article

SN - 1525-2027

VL - 17

SP - 16

EP - 27

JO - Geochemistry, Geophysics, Geosystems

JF - Geochemistry, Geophysics, Geosystems

IS - 1

ER -

Subduction system and flat slab beneath the Eastern Cordillera of Colombia

Resumen

Acceder al documento

Huella

Citar esto