Geochemistry of oceanic crust beneath Costa Rica

Fuente: PANGAEA
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Autores principales: Hoernle, Kaj, Abt, David, Fischer, Karen M, Nichols, Holly, Hauff, Folkmar, Abers, Geoffrey A, van den Bogaard, Paul, Heydolph, Ken, Alvarado, Guillermo, Protti, Marino, Strauch, Wilfried
Formato: Dataset Open Access
Lenguaje:en
Publicado: PANGAEA 2008
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author Hoernle, Kaj
Abt, David
Fischer, Karen M
Nichols, Holly
Hauff, Folkmar
Abers, Geoffrey A
van den Bogaard, Paul
Heydolph, Ken
Alvarado, Guillermo
Protti, Marino
Strauch, Wilfried
author_facet Hoernle, Kaj
Abt, David
Fischer, Karen M
Nichols, Holly
Hauff, Folkmar
Abers, Geoffrey A
van den Bogaard, Paul
Heydolph, Ken
Alvarado, Guillermo
Protti, Marino
Strauch, Wilfried
collection Datos científicos de ciencias marinas y ambientales
contents Resolving flow geometry in the mantle wedge is central to understanding the thermal and chemical structure of subduction zones, subducting plate dehydration, and melting that leads to arc volcanism, which can threaten large populations and alter climate through gas and particle emission. Here we show that isotope geochemistry and seismic velocity anisotropy provide strong evidence for trench-parallel flow in the mantle wedge beneath Costa Rica and Nicaragua. This finding contradicts classical models, which predict trench-normal flow owing to the overlying wedge mantle being dragged downwards by the subducting plate. The isotopic signature of central Costa Rican volcanic rocks is not consistent with its derivation from the mantle wedge (Feigenson et al., 2004, doi:10.1029/2003GC000621; Herrstom et al., 1995, doi:10.1130/0091-7613(1995)023<0617:VILCAW>2.3.CO;2; Abratis and Woerner, 2001) or eroded fore-arc complexes (Goss and Kay, 2006, doi:10.1029/2005GC001163) but instead from seamounts of the Galapagos hotspot track on the subducting Cocos plate. This isotopic signature decreases continuously from central Costa Rica to northwestern Nicaragua. As the age of the isotopic signature beneath Costa Rica can be constrained and its transport distance is known, minimum northwestward flow rates can be estimated (~63-190 mm/yr) and are comparable to the magnitude of subducting Cocos plate motion (approx85 mm/yr). Trench-parallel flow needs to be taken into account in models evaluating thermal and chemical structure and melt generation in subduction zones.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_773166
institution PANGAEA
language en
publishDate 2008
publisher PANGAEA
record_format pangaea
spellingShingle Geochemistry of oceanic crust beneath Costa Rica
Hoernle, Kaj
Abt, David
Fischer, Karen M
Nichols, Holly
Hauff, Folkmar
Abers, Geoffrey A
van den Bogaard, Paul
Heydolph, Ken
Alvarado, Guillermo
Protti, Marino
Strauch, Wilfried
170-1039C; 170-1040C; Costa Rica subduction complex, North Pacific Ocean; DRILL; Drilling/drill rig; Joides Resolution; Leg170; Ocean Drilling Program; ODP
Resolving flow geometry in the mantle wedge is central to understanding the thermal and chemical structure of subduction zones, subducting plate dehydration, and melting that leads to arc volcanism, which can threaten large populations and alter climate through gas and particle emission. Here we show that isotope geochemistry and seismic velocity anisotropy provide strong evidence for trench-parallel flow in the mantle wedge beneath Costa Rica and Nicaragua. This finding contradicts classical models, which predict trench-normal flow owing to the overlying wedge mantle being dragged downwards by the subducting plate. The isotopic signature of central Costa Rican volcanic rocks is not consistent with its derivation from the mantle wedge (Feigenson et al., 2004, doi:10.1029/2003GC000621; Herrstom et al., 1995, doi:10.1130/0091-7613(1995)023<0617:VILCAW>2.3.CO;2; Abratis and Woerner, 2001) or eroded fore-arc complexes (Goss and Kay, 2006, doi:10.1029/2005GC001163) but instead from seamounts of the Galapagos hotspot track on the subducting Cocos plate. This isotopic signature decreases continuously from central Costa Rica to northwestern Nicaragua. As the age of the isotopic signature beneath Costa Rica can be constrained and its transport distance is known, minimum northwestward flow rates can be estimated (~63-190 mm/yr) and are comparable to the magnitude of subducting Cocos plate motion (approx85 mm/yr). Trench-parallel flow needs to be taken into account in models evaluating thermal and chemical structure and melt generation in subduction zones.
title Geochemistry of oceanic crust beneath Costa Rica
topic 170-1039C; 170-1040C; Costa Rica subduction complex, North Pacific Ocean; DRILL; Drilling/drill rig; Joides Resolution; Leg170; Ocean Drilling Program; ODP
url https://doi.org/10.1594/PANGAEA.773166