Y. Gallet et al., UPPER ANISIAN TO LOWER CARNIAN MAGNETOSTRATIGRAPHY FROM THE NORTHERN CALCAREOUS ALPS (AUSTRIA), J GEO R-SOL, 103(B1), 1998, pp. 605-621
We present a magnetostratigraphic study of three pelagic limestone sec
tions (Gamsstein, Mendlingbach and Mayerling) from the eastern part of
the Northern Calcareous Alps. Together these sections, which contain
a rich conodont fauna, yield a sedimentary record encompassing the upp
ermost Anisian, the Ladinian and the Lower Carnian. Thermal demagnetiz
ation and isothermal remanent magnetization experiments indicate that
the magnetization is essentially carried by a mineral of the magnetite
family. The high unblocking temperature components isolated from the
three sections provide clear magnetic polarity zonations. Correlations
between these results, based on the biostratigraphic data and tephroc
hronology, allow the construction of a composite magnetic polarity seq
uence from the Illyrian substage (Upper Anisian) to the Julian 2 zone
(Lower Carnian). This sequence contains 17 well-defined polarity rever
sals, and eight more poorly defined intervals. Correlations can be sug
gested between the new data and other magnetostratigraphic results pre
viously obtained from marine sections. We estimate that the magnetic r
eversal frequency was 2.5 to 3.6 reversals per million years during th
e Ladinian.