Enhanced airborne dispersal of silicic tephras during the onset of Northern Hemisphere glaciations, from 6 to 0 Ma records of explosive volcanism and climate change in the subpolar North Atlantic.

Lacasse, Christian and van den Bogaard, Paul (2002) Enhanced airborne dispersal of silicic tephras during the onset of Northern Hemisphere glaciations, from 6 to 0 Ma records of explosive volcanism and climate change in the subpolar North Atlantic. Geology, 30 . pp. 623-626. DOI 10.1130/0091-7613(2002)030<0623:EADOST>2.0.CO;2.

[img] Text
Lacasse.pdf - Published Version
Restricted to Registered users only

Download (759Kb) | Contact

Supplementary data:

Abstract

A 6-m.y.-long composite marine record of explosive silicic volcanism from five Ocean Drilling Program sites in the subpolar North Atlantic was compared with several marine records of global and local paleoclimate proxies (benthic δ18O and ice-rafted debris records). Coarsening and high frequency of occurrence of Icelandic tephras were recorded in 3.6–3 Ma sediments, suggesting that these tephras were dispersed farther from the source by enhanced westerly winds over the subpolar North Atlantic. The 40Ar/39Ar ages were determined by laser probe on K-feldspar and biotite phenocrysts of tephras that were erupted from the Jan Mayen volcanic system. Compared to the tuned paleomagnetic age model, the 40Ar/39Ar dating (0.618 ± 0.007 Ma to 4.90 ± 0.05 Ma) yields a new age model that postdates by 155 k.y. the inception of ice rafting on the Iceland Plateau during the cold marine isotope stage M2 (i.e., 3.3–3.14 Ma).

Document Type: Article
Keywords: 40Ar/39Ar, explosive eruptions, ice rafting, Iceland, Jan Mayen, tephra
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1130/0091-7613(2002)030<0623:EADOST>2.0.CO;2
ISSN: 0091-7613
Projects: ODP, DSDP
Date Deposited: 18 Feb 2008 17:25
Last Modified: 26 Sep 2017 08:05
URI: http://oceanrep.geomar.de/id/eprint/4039

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...