sedimentary xenolith on Surtsey
Length of hammer 28 cm
© Photo: L.A.Simonarson
'You are never to old to learn', it is said. But I must admit
that some new kinds of information sounds more like a joke....like
the finding of fossils on Surtsey - an island
only 39 years old . The fossils where obtained as early as 5 years
after the eruption!
But according to a report published in the Surtsey Research
Progress Report VII in 1974
that is a fact. This is what it says: 'During the Surtsey eruption
sedimentary xenoliths were carried upwards with the hot magma and
are now found
in the tephra on Surtsey.'
Well, that makes it a little more possible to understand, but how
did those fossils happen
to ride on the hot magma - and where did it come from?
The report explains: 'Data from a 1.565 m deep drillhole on Heimaey
(700 to 800 m ) thick series of sedimentary layers in the stratigraphic
the Westmann Islands. Those beds have probably supplied the fossiliferous
on the islands.'
So this layer which is believed to cover an area from a bit up the
coast inside the Westmann Islands and out as far as behind Surtsey,
which is the uttermost of the islands, somehow
consists of old fossils, and when magma came up during the eruption
some fragments (xenoliths) of that layer were carried up to the
Did they find any dinosauruses, mammoths or something like that?
But quite a lot (several hundreds) of foraminiferas (Foraminifera
are tiny single-celled organisms thatconstruct shells. They inhabit
a wide range of marine environments,
from the intertidal zone to the deep sea in all regions. - just
in case you didn't know).,
Also found were some molluscas (Molluscs are one of the most
diverse groups of
invertebrate animals - both in form and habitat. Mollusca: Snails,
mussels, squids, octopi, chitons, and tusk shells).
islandica, which can be 132 years old
and apparently much more as a fossil....
Several fragments of the mollusca called Arctica
islandica were also found, and some of
them were taken from two blocks and dated radiometrically. One block
fraction ) was approximately 11.000 years old, while the other (mainly
was 6.200 years.
The report concluded with the following words: 'The marine fauna
of species living at the present time which is in agreement with
the radiocarbon dates.
The fauna is, moreover, north boreal, i.e. similar to the fauna
of South Iceland today. Several species of foraminifera found in
the xenoliths have not been recorded as living nowadays in Icelandic
waters. However, the recent foraminifera fauna of Iceland is not
sufficiently well known, so a comparison is probably of no great
The text above is Based upon two
reports by Leifur A Simonarson,
Scince Institute, University of Iceland, Reykjavik.
Surtsey Research Progress Report VII and IX.
Here you can find more information about:
|| Bird migration
|| How life developed
|| The eruption
February 18th, 2003
more pages are coming up, and already existing pages
still needs more text and pictures
Any questions, or a feeling of knowing more, just get in touch!