Low-volume intraplate volcanism in the Early/Middle Jurassic Pacific basin documented by accreted sequences in Costa Rica

Détails

ID Serval
serval:BIB_9EA3F0B4E1F6
Type
Article: article d'un périodique ou d'un magazine.
Sous-type
Compte-rendu: analyse d'une oeuvre publiée.
Collection
Publications
Titre
Low-volume intraplate volcanism in the Early/Middle Jurassic Pacific basin documented by accreted sequences in Costa Rica
Périodique
Geochemistry, Geophysics, Geosystems
Auteur(s)
Buchs D.M., Pilet S., Baumgartner P.O., Cosca M., Flores K.E., Bandini A.N.
ISSN
1525-2027
Statut éditorial
Publié
Date de publication
20/05/2013
Peer-reviewed
Oui
Volume
14
Pages
1552-1568
Langue
anglais
Résumé
Countless seamounts occur on Earth that can provide important constraints on intraplate volcanism and plate tectonics in the oceans, yet their nature and origin remain poorly known due to difficulties in investigating the deep ocean. We present here new lithostratigraphic, age and geochemical data from Lower/Middle Jurassic and Lower Cretaceous sequences in the Santa Rosa accretionary complex, Costa Rica, which offer a valuable opportunity to study a small-sized seamount from a subducted plate segment of the Pacific basin. The seamount is characterized
by very unusual lithostratigraphic sequences with sills of potassic alkaline basalt emplaced within thick beds of radiolarite, basaltic breccia and hyaloclastite. An integration of new geochemical, biochronological and geochronological data with lithostratigraphic observations suggests that the seamount formed ~175Ma ago on thick oceanic crust away from subduction zones and mid-ocean ridges. This seamount traveled ~65Ma in the Pacific before accretion. It resembles lithologically and compositionally “petit-spot” volcanoes found off Japan, which form in
response to plate flexure near subduction zones. Also, the composition of the sills and lava flows in the accreted seamount closely resembles that of potassic alkaline basalts produced by lithosphere cracking along the Line Islands chain. We hypothesize based on these observations, petrological constraints and formation of the accreted seamount coeval with the early stages of development of the Pacific plate that the seamount formed by extraction of small volumes ofmelt fromthe base of the lithosphere in response to propagating fractures at the scale of the Pacific basin.
Mots-clé
accretionary complex, seamount, OIB, intraplate volcanism, lithosphere cracking, metasomatism
Open Access
Oui
Création de la notice
14/03/2017 10:11
Dernière modification de la notice
20/08/2019 16:04
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