Late Cenozoic tephrostratigraphy offshore the southern Central American Volcanic Arc: 1. Tephra ages and provenance.

Schindlbeck, Julie C. , Kutterolf, Steffen, Freundt, Armin , Alvarado, G. E., Wang, K.-L., Straub, S. M., Hemming, S. R., Frische, M. and Woodhead, J. D. (2016) Late Cenozoic tephrostratigraphy offshore the southern Central American Volcanic Arc: 1. Tephra ages and provenance. Open Access Geochemistry, Geophysics, Geosystems, 17 (11). pp. 4641-4668. DOI 10.1002/2016GC006503.

[img]
Preview
Text
ggge21178.pdf - Accepted Version

Download (6Mb) | Preview

Supplementary data:

Abstract

We studied the tephra inventory of 18 deep sea drill sites from six DSDP/ODP legs (Legs 84, 138, 170, 202, 205, 206) and two IODP legs (Legs 334 and 344) offshore the southern Central American Volcanic Arc (CAVA). Eight drill sites are located on the incoming Cocos plate and ten drill sites on the continental slope of the Caribbean plate. In total we examined ∼840 ash-bearing horizons and identified ∼650 of these as primary ash beds of which 430 originated from the CAVA. Correlations of ash beds were established between marine cores and with terrestrial tephra deposits, using major and trace element glass compositions with respect to relative stratigraphic order. As a prerequisite for marine-terrestrial correlations we present a new geochemical data set for significant Neogene and Quaternary Costa Rican tephras. Moreover, new Ar/Ar ages for marine tephras have been determined and marine ash beds are also dated using the pelagic sedimentation rates. The resulting correlations and provenance analyses build a tephrochronostratigraphic framework for Costa Rica and Nicaragua that covers the last >8 Myr. We define 39 correlations of marine ash beds to specific tephra formations in Costa Rica and Nicaragua; from the 4.15 Ma Lower Sandillal Ignimbrite to the 3.5 ka Rincón de la Vieja Tephra from Costa Rica, as well as another 32 widely distributed tephra layers for which their specific region of origin along Costa Rica and Nicaragua can be constrained.

Document Type: Article
Additional Information: All geochemical data and sample locations are given in the Supporting Information Data Set S1–S9.
Keywords: Central America; magma production rates; explosive volcanism from Costa Rica and Nicaragua; provenance; tephrostratigraphy; sedimentation rates
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1002/2016GC006503
ISSN: 1525-2027
Projects: IODP, DSDP, ODP
Date Deposited: 07 Nov 2016 08:52
Last Modified: 01 Feb 2019 15:14
URI: http://oceanrep.geomar.de/id/eprint/34576

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...