Jökull - 01.12.1982, Blaðsíða 95

Paleomagnetic Research on Icelandic Rocks
— A Bibliographical Review 1951 — 1981
LEÓ KRISTJÁNSSON
Science Institute, University of Iceland,
Dunhagi 3, 107 Reykjavík, Iceland
ABSTRACT
This paper covers the tústory of paleomagnetic research in
Iceland from its beginnings to about 1981. It is primarily
wntten for students and geoscientists who may be interested
in using paleomagnetic directons as an aid in stratigraphic
and tectonic mapping in Iceland. Emphasis is on laboratory
measurements of magnetic direction and intensity in rocks;
coverage of rock-magnetic measurements is also fairly com-
plete, but studies of magnetic polarity in the field are only
partly covered. Papers interpreting magneticfield anomalies
over Iceland in lerms of magnetic measurements on rocks are
mcluded, but many papers dealing with other aspects of
magnetic anomalies have been omitted.
This review is mostly restricted to published papers con-
taining predominantly original results from Iceland, with
only occasional references to conference abslracts, theses,
surnmaiy þapers, and intemal reports. Papers that deal with
paleofield directions are reviewed first, roughly in time se-
quence by authors. This isfollowed by chaplers on paleoin-
tensities, anomaly interpretation, rock magnetism, and mis-
cellaneous other topics.
It may be concluded that paleomagnetic research in Ice-
land has played a significant part in the development of
modem ideas on the history of the geomagnetic field in
geological time (especially during the 1950’s and 1960’s)
and in research on magnetic properties of rocks. A few
biographical details are included.
introduction
Paleomagnetic research in Iceland may by said to
have begun in 1950-51. This was a time when many
important branches ofearth science were enteringa
period of rapid expansion and general acceptance,
after either having been the pursuit of few isolated
individuals for decades, or having sprung into
existence with new technical inventions made
during the war. Many geoscience concepts,
methods, and pieces of equipment that are now
familiar even to high school students, had not been
heardofin 1950.
Due to its relevance to navigation (and later to
communication, surveys, and prospecting) the geo-
magnetic field had been studied in many observ-
atories and laboratories since the early 19th
century. A major monograph on Geomagnetism by S.
Chapman and J. Bartels, appeared in 1940. How-
ever, the origin of the internal field and its variations
was not understood, and by the 1930’s it was
appreciated that studies on fossil remanent magne-
tization in rocks and artifacts might aid this under-
standing. Research groups in France, Japan and
Germany had begun to study the intensity, direct-
ion and stability of natural remanent magnetization
(N. R. M.) in rocks early in this century, and
described individual occurrences of inverse re-
manence. The first book on the subject, H. Haalck’s
Gesteinsmagnetismus, was published in 1942. 'Fhis
book concludes that observed variations of
remanence in rocks are predominantly due to local
phenomena, such as temperature variations in the
rock strata, lightning, and seismic activity.
Through the late forties, it must be presumed
that appreciation of the potential usefulness of
paleomagnetism in studies of stratigraphy,
tectonics, and apparent polar wandering was
gradually increasing among solid earth scientists.
In 1947-50, several landmark papers on the subject
of geomagnetism and paleomagnetism appeared,
These included a new description and analysis of
the geomagnetic lield by E. Vestine and others,
papers on the nature of this field inside the earth by
E. Bullard and by W. Elsasser, L. Néel’s classic
theories of thermo-remanence (T. R. M.) and
viscous remanence (V. R. M.) in crystal grains,
extensive remanence measurements on sediments
JÖKULL 32. ÁR 91