Neogene alkaline basaltic volcanic fields in the western Pannonian Basin, Hungary,
including the Bakony-Balaton Highland and the Little Hungarian Plain volcanic fields
are the erosional remnants of clusters of small-volume, possibly monogenetic volcanoes.
Moderately to strongly eroded maars, tuff rings, scoria cones, and associated lava
flows span an age range of ca. 6 Myr as previously determined by the K/Ar method.
High resolution Ar-40/ Ar-39 plateau ages on 18 samples have been obtained to determine
the age range for the western Pannonian Basin Neogene intracontinental volcanic province.
The new Ar-40/Ar-39 age determinations confirm the previously obtained K/Ar ages in
the sense that no systematic biases were found between the two data sets. However,
our study also serves to illustrate the inherent advantages of the Ar-40/Ar-39 technique:
greater analytical precision, and internal tests for reliability of the obtained results
provide more stringent constraints on reconstructions of the magmatic evolution of
the volcanic field. Periods of increased activity with multiple eruptions occurred
at ca. 7.95 Ma, 4.10 Ma, 3.80 Ma and 3.00 Ma. These new results more precisely date
remnants of lava lakes or flows that define geomorphological marker horizons, for
which the age is significant for interpreting the erosion history of the landscape.
The results also demonstrate that during short periods of more intense activity not
only were new centers formed but pre-existing centers were rejuvenated. (C) 2007 Published
by Elsevier B.V.