Age and geochemistry of basaltic complexes in western Costa Rica: Contributions to the geotectonic evolution of Central America.

Hauff, Folkmar, Hoernle, Kaj , van den Bogaard, Paul, Alvarado, Guillermo and Garbe-Schönberg, Dieter (2000) Age and geochemistry of basaltic complexes in western Costa Rica: Contributions to the geotectonic evolution of Central America. Open Access Geochemistry, Geophysics, Geosystems, 1 (1). p. 1009. DOI 10.1029/1999GC000020.

[img]
Preview
Text
ggge16.pdf - Published Version

Download (2343Kb) | Preview

Supplementary data:

Abstract

The age and origin of magmatic complexes along the Pacific Coast of Central America have important
implications for the origin and tectonic evolution of this convergent plate margin. Here we present
new 40Ar/39Ar laser age dates, major and trace element data, and initial Sr-Nd-Pb isotope ratios. The 124–
109 Ma tholeiitic portions of the Santa Elena complex formed in a primitive island arc setting, believed to
be part of the Chortis subduction zone. The geochemical similarities between the Santa Elena and Tortugal
alkaline volcanic rocks suggest that Chortis block may extend south of the Hess Escarpment. The Nicoya,
Herradura, Golfito, and Burica complexes and the tholeiitic Tortugal unit formed between 95 and 75 Ma
and appear to be part of the Caribbean Large Igneous Province, thought to mark the initiation of the
Gala´pagos hotspot. The Quepos and Osa complexes (65–59 Ma) represent accreted sections of an ocean
island and an aseismic ridge, respectively, interpreted to reflect part of the Gala´pagos paleo-hotspot track.
An Oligocene unconformity throughout Central America may be related to the mid-Eocene accretion of the
Quepos and Osa complexes.

Document Type: Article
Keywords: Central America; oceanic crust; 40Ar/39Ar-geochronology; geochemistry; plate tectonics; Gala´pagos hotspot
Research affiliation: Kiel University
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1029/1999GC000020
ISSN: 1525-2027
Projects: TICOSECT
Date Deposited: 25 Oct 2013 12:20
Last Modified: 07 Nov 2017 09:46
URI: http://oceanrep.geomar.de/id/eprint/22279

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...