In:
Journal of petrology, Oxford : Oxford Univ. Press, 1960, 49(2008), 10, Seite 1781-1815, 1460-2415
In:
volume:49
In:
year:2008
In:
number:10
In:
pages:1781-1815
Description / Table of Contents:
The igneous forearc basement along the Pacific coast of northern Central America (between southern Mexico and Costa Rica) comprises a highly tectonized accretionary assemblage of igneous and ultramafic rocks. Volcanic and gabbroic rocks with primitive arc geochemical signatures formed between ~100 and ≥180 Ma and are interpreted to have originated by arc magmatism resulting from subduction of the PacificFarallon plate. Geochemically enriched ocean island basalt (OIB)-like units are interpreted as accreted seamounts and islands of a hotspot track, which was active between ≥220 and 100 Ma and originated from a hotspot located in the central Pacific. Based on their combined Pb, Nd and Hf isotopic compositions an affiliation of these rocks with the Caribbean Large Igneous Province or the present-day Galápagos hotspot appears unlikely. Rocks of similar age and geochemistry are exposed on the Santa Elena Peninsula in Costa Rica, suggesting that a similar forearc basement is accreted to the continental Chortis Block from southern Mexico to Costa Rica.
Type of Medium:
Online Resource
Pages:
graph. Darst
ISSN:
1460-2415
DOI:
10.1093/petrology/egn046
Language:
English
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