Structural evolution of the Nekézseny Fault – a displaced segment of the Dinaric-ALCAPA contact zone in NE Hungary (Bükk and Uppony Hills)

Abstract

The Bükk and Uppony Hills (NE Hungary) are two adjacent structural units with correlations to the Northern Dinarides and Inner Western Carpathians (ALCAPA), respectively. These two units are separated by the Nekézseny Fault, which may therefore be considered as a presently displaced segment of the Dinaric-ALCAPA contact zone (Schmid et al. 2008). Along this contact zone, the Bükk-type Permo-Mesozoic formations are thrust over the Paleozoic and Senonian formations of the Uppony Unit (Schréter 1945). Despite of the Nekézseny Fault being a terrain boundary, its structural evolution has not been studied in details. Preliminary structural data suggested multiple faulting events between the latest Senonian and early Miocene (Fodor et al. 2005), however, the initial age of the contact zone has remained uncertain.