Náttúrufræðingurinn - 2012, Qupperneq 111

111
Tímarit Hins íslenska náttúrufræðifélags
Heimildir
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Sigmarsson 2011. Geodynamics of rift-plume interaction in Iceland as
constrained by new 40Ar/39Ar and in situ U-Pb zircon ages. Earth and
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Póst- og netföng höfunda/Authors’ addresses
Olgeir Sigmarsson
Jarðvísindastofnun Háskólans, Öskju, Sturlugötu 7, IS-101 Reykjavík.
Laboratoire Magmas et Volcans,
Université Blaise Pascal og CNRS,
5 rue Kessler, 63038 Clermont-Ferrand, Frakkland
olgeir@raunvis.hi.is
Erwan Martin
Institut des Sciences de la Terre de Paris,
Université Paris 6, 75005, Paris, France.
erwan.martin@upmc.fr
Jean-Louis Paquette og Valerie Bosse
J.L.Paquette og V.Bosse@opgc.univ-bpclermont.fr
Kristján Geirsson
Umhverfisstofnun,
Suðurlandsbraut 24,
IS-108 Reykjavík
kristjan@umhverfisstofnun.is
Um höfundana
Olgeir Sigmarsson (f. 1958) lauk doktorsprófi í jarðefna-
fræði frá Blaise Pascal háskólanum í Clermont-Ferrand,
Frakklandi 1990. Hann starfar við Vísindastofnun Frakk-
lands (Centre National de la Recherche Scientifique) og
Jarðvísindastofnun Háskólans.
Erwan Martin (f. 1979) lauk doktorsprófi í jarðefnafræði
frá Blaise Pascal háskóla, Clermont-Ferrand, Frakklandi
2006. Hann kennir nú við Parísarháskóla.
Jean-Louis Paquette vinnur við Vísindastofnun Frakk-
lands og Blaise Pascal háskólann í Clermont-Ferrand,
Frakklandi.
Valerie Bosse vinnur við Blaise Pascal háskólann í
Clermont-Ferrand, Frakklandi.
Kristján Geirsson (f. 1968) lauk doktorsprófi í berg- og
steindafræði við Pierre et Marie Curie háskólann í París,
Frakklandi 1993. Hann starfar á Umhverfisstofnun.
the NIRZ half spreading rate has been
between 0.7 and 1.1 cm/yr as revealed
by linear correlation between age and
longitude. The excess width of Iceland
can thus not be explained by faster
spreading rate in the past. This ~200 km
‘excess’ of crust must take into account
the eastward relocation of the rift zone
and corresponding older crustal cap-
ture over the course of Iceland’s geo-
logical history.
The need for rift relocations and
crustal capture to explain the width of
Iceland strongly suggests that during
rift/plume interaction the mantle
plume plays an active role. It forces the
active rift zone to be frequently relo-
cated by rift jumps above its center,
leaving inactive rift zones as older syn-
clines in the geological record. This re-
sults in an eastward position of the rift
zone in Iceland relative to the North
Atlantic ridge.