THE GENESIS OF LOFER CYCLES OF THE DACHSTEIN LIMESTONE, NORTHERN CALCAREOUS ALPS, AUSTRIA

Peritidal carbonate platform Lofer cycles have been regarded as a reco rd of sea-level oscillations driven by variations in the earth's orbit . Fresh analysis of a newly measured 700 m thick section from the Stei nernes Meer is presented here. Estimation of stratigraphic completenes s indicates that this sequence is only 0.75-9.5% complete, strongly su ggesting that Milankovitch patterns are not preserved. Analysis of cyc le thickness-frequency distributions reveals an exponential pattern, s trongly suggestive of aperiodic, random deposition rather than periodi c deposition in response to orbital forcing. Evidence for the importan ce of autocyclic processes (e.g. lateral migration of inter- to suprat idal mudbanks and subtidal areas) and syn-sedimentary tectonic downfau lting events within this already active Late Triassic extensional zone is presented.