Pleistocene subglacial volcanism in Iceland: tectonic implications

Research areas:

• Environnement, Paléo-Environnement et Bio-Indicateurs (2011 - 2016)

Year:

1998

Authors:

• Olivier Bourgeois
• O Dauteuil
• B Van Vliet-Lanoe

Journal:

EARTH AND PLANETARY SCIENCE LETTERS

Volume:

164

Number:

1-2

Pages:

165-178

Month:

DEC 15

ISSN:

0012-821X

BibTex:

@article{WOS:000077815900013, author = "Olivier Bourgeois and O Dauteuil and B Van Vliet-Lanoe", abstract = "At several stages during the last 700 kyr, tectonic and volcanic activity due to Lithospheric spreading occurred beneath a 1000-1500 m thick ice cap in Iceland. Magmatic activity has been recorded by the emplacement of subglacial Volcanic edifices. Table volcanoes are the subglacial equivalent of aerial shield volcanoes. Hyaloclastite ridges are the subglacial equivalent of aerial eruptive fissures. Some hyaloclastite ridges are located in currently inactive areas, whereas they are nearly absent in some parts of the currently active Neovolcanic Zone. A part of this discrepancy can be attributed to glacial erosion. A manual reconstruction of the flowing pattern of the ice cap, based on glacial landforms, shows that some parts of the Neovolcanic Zone were occupied by fast flowing ice streams. In these areas, most hyaloclastite ridges have been removed as eruptions proceeded: fast ice flow and water/debris flows triggered by volcanic eruptions have transported subglacial volcanic products to the sea. Subglacial volcanic products have been preserved beneath ice divides, where ice motion was slower, and in some table volcanoes, where magma supply was sufficient to counteract removal by ice how Once the effect of glacial removal has been subtracted, the arrangement of the subglacial volcanic edifices appears clearly. Similarly to the post-glacial eruptive fissures, the hyaloclastite ridges are gathered in swarms associated with central volcanoes located in the Neovolcanic Zone. However, the area covered by hyaloclastite ridges is wider than the extent of the currently active fissure swarms. This discrepancy suggests either continuous wandering of the volcanic activity from one fissure swarm to another for the last 700 kyr, or narrowing of the active rift zone at the end of the last glaciation. (C) 1998 Elsevier Science B.V. All rights reserved.", doi = "10.1016/S0012-821X(98)00201-5", extra = "PICL", issn = "0012-821X", journal = "EARTH AND PLANETARY SCIENCE LETTERS", month = "DEC 15", number = "1-2", pages = "165-178", title = "{P}leistocene subglacial volcanism in {I}celand: tectonic implications", volume = "164", year = "1998", }

Abstract:

At several stages during the last 700 kyr, tectonic and volcanic
activity due to Lithospheric spreading occurred beneath a 1000-1500 m
thick ice cap in Iceland. Magmatic activity has been recorded by the
emplacement of subglacial Volcanic edifices. Table volcanoes are the
subglacial equivalent of aerial shield volcanoes. Hyaloclastite ridges
are the subglacial equivalent of aerial eruptive fissures. Some
hyaloclastite ridges are located in currently inactive areas, whereas
they are nearly absent in some parts of the currently active Neovolcanic
Zone. A part of this discrepancy can be attributed to glacial erosion. A
manual reconstruction of the flowing pattern of the ice cap, based on
glacial landforms, shows that some parts of the Neovolcanic Zone were
occupied by fast flowing ice streams. In these areas, most hyaloclastite
ridges have been removed as eruptions proceeded: fast ice flow and
water/debris flows triggered by volcanic eruptions have transported
subglacial volcanic products to the sea. Subglacial volcanic products
have been preserved beneath ice divides, where ice motion was slower,
and in some table volcanoes, where magma supply was sufficient to
counteract removal by ice how Once the effect of glacial removal has
been subtracted, the arrangement of the subglacial volcanic edifices
appears clearly. Similarly to the post-glacial eruptive fissures, the
hyaloclastite ridges are gathered in swarms associated with central
volcanoes located in the Neovolcanic Zone. However, the area covered by
hyaloclastite ridges is wider than the extent of the currently active
fissure swarms. This discrepancy suggests either continuous wandering of
the volcanic activity from one fissure swarm to another for the last 700
kyr, or narrowing of the active rift zone at the end of the last
glaciation. (C) 1998 Elsevier Science B.V. All rights reserved.