40Ar/39Ar dating of detrital white mica of Upper Paleozoic sandstones in the Carnic Alps (Austria)

Author(s)
D. Mader, F. Neubauer, Robert Handler
Abstract

New information on the geodynamic development and the provenance for Carboniferous to Permian successions exposed within the Carnic Alps is supplied by an integrated approach of microprobe analysis and Ar/Ar dating of detrital white mica. Ar/Ar analyses of detrital white mica concentrates (4-10 grains) from syn- and post-orogenic Mississippian to Late Permian successions display an apparently uniform population and time lag of the isotopic ages with respect to the stratigraphic age of their host rock: early Variscan ages (373-396 Ma) are reported within synorogenic Visean-Namurian turbiditic sandstones, Variscan ages (333-309 Ma) in post-orogenic Pennsylvanian and Permian terrestrial and shallow marine sandstones. Detrital white micas from Mississippian syn-orogenic sandstones indicate an intermediate time interval between the cooling of the source rock and deposition, typical for compressional accretionary wedge settings. Furthermore, these ages argue for a Middle Devonian tectonothermal event in the hinterland. Detrital white micas from Pennsylvanian sandstones indicate a very narrow time lag between post-Variscan cooling of the source region and the depositional age. This points to a rapid exhumation of rocks in the source region from mid-crustal levels prior to the deposition of these sediments.

Organisation(s)
Department of Lithospheric Research
External organisation(s)
Paris-Lodron Universität Salzburg
Journal
Geologica Carpathica
Volume
58
Pages
133-144
No. of pages
12
ISSN
1335-0552
Publication date
04-2007
Peer reviewed
Yes
Austrian Fields of Science 2012
105116 Mineralogy, 105106 Geodynamics, 105101 General geology
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/2db2bd85-c5c1-46cb-a624-a5b7a58377ff