Imaging the transition from flat to normal subduction: variations in the structure of the Nazca slab and upper mantle under southern Peru and northwestern Bolivia

Simple item page
dc.contributor.authorScire, Alissa
dc.contributor.authorZandt, George
dc.contributor.authorBeck, Susan
dc.contributor.authorLong, Maureen
dc.contributor.authorWagner, Lara
dc.contributor.authorMinaya, Estela
dc.contributor.authorTavera, Hernando
dc.coverage.spatialSudamérica
dc.date.accessioned2018-08-08T14:04:55Z
dc.date.available2018-08-08T14:04:55Z
dc.date.issued2016-01
dc.description.abstractTwo arrays of broad-band seismic stations were deployed in the north central Andes between 8° and 21°S, the CAUGHT array over the normally subducting slab in northwestern Bolivia and southern Peru, and the PULSE array over the southern part of the Peruvian flat slab where the Nazca Ridge is subducting under South America. We apply finite frequency teleseismic P- and S-wave tomography to data from these arrays to investigate the subducting Nazca plate and the surrounding mantle in this region where the subduction angle changes from flat north of 14°S to normally dipping in the south. We present new constraints on the location and geometry of the Nazca slab under southern Peru and northwestern Bolivia from 95 to 660 km depth. Our tomographic images show that the Peruvian flat slab extends further inland than previously proposed along the projection of the Nazca Ridge. Once the slab re-steepens inboard of the flat slab region, the Nazca slab dips very steeply (∼70°) from about 150 km depth to 410 km depth. Below this the slab thickens and deforms in the mantle transition zone. We tentatively propose a ridge-parallel slab tear along the north edge of the Nazca Ridge between 130 and 350 km depth based on the offset between the slab anomaly north of the ridge and the location of the re-steepened Nazca slab inboard of the flat slab region, although additional work is needed to confirm the existence of this feature. The subslab mantle directly below the inboard projection of the Nazca Ridge is characterized by a prominent low-velocity anomaly. South of the Peruvian flat slab, fast anomalies are imaged in an area confined to the Eastern Cordillera and bounded to the east by well-resolved low-velocity anomalies. These low-velocity anomalies at depths greater than 100 km suggest that thick mantle lithosphere associated with underthrusting of cratonic crust from the east is not present. In northwestern Bolivia a vertically elongated fast anomaly under the Subandean Zone is interpreted as a block of delaminating lithosphere.es_ES
dc.description.peer-reviewPor pareses_ES
dc.formatapplication/pdfes_ES
dc.identifier.citationScire, A., Zandt, G., Beck, S., Long, M., Wagner, L., Minaya, E., & Tavera, H. (2016). Imaging the transition from flat to normal subduction: variations in the structure of the Nazca slab and upper mantle under southern Peru and northwestern Bolivia.==$Geophysical Journal International, 204$==(1), 457–479. https://doi.org/10.1093/gji/ggv452es_ES
dc.identifier.doihttps://doi.org/10.1093/gji/ggv452es_ES
dc.identifier.govdocindex-oti2018
dc.identifier.journalGeophysical Journal Internationales_ES
dc.identifier.urihttp://hdl.handle.net/20.500.12816/2310
dc.language.isoenges_ES
dc.publisherOxford University Presses_ES
dc.relation.ispartofurn:issn:0956-540X
dc.rightsinfo:eu-repo/semantics/openAccesses_ES
dc.rights.urihttps://creativecommons.org/licences/by/4.0/es_ES
dc.subjectTomographyes_ES
dc.subjectSeismic tomographyes_ES
dc.subjectSubduction zone processeses_ES
dc.subjectDynamics of lithosphere and mantlees_ES
dc.subjectSouth Americaes_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.00es_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.04es_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.06es_ES
dc.titleImaging the transition from flat to normal subduction: variations in the structure of the Nazca slab and upper mantle under southern Peru and northwestern Boliviaes_ES
dc.typeinfo:eu-repo/semantics/articlees_ES

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Scire-2015.pdf
Size:
19.06 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Artículos Científicos