The Mesozoic sedimentary sequences at Villány (southern Hungary)

Abstract

The article summarizes the 150 years’ history of research on the Villány Mesozoic, with a focus on the Templomhegy at Villány. Short descriptions are given of the formerly excellent outcrops (e.g. quarries, road cut, tunnel, boreholes)
which four decades ago (when the author has started his studies at the location) were in good condition. Since than they
have been badly damaged or covered. The retrospective parts of the article are followed by new data or descriptions which
previousli had not been fully documented. These include the geological sketch of the Templom-hegy; the detailed
description, photographic documentation and redefinition of the Upper Triassic Mészhegy Formation; the description of
the Pliensbachian Somssichhegy Formation and the Bathonian–Callovian Villány Formation. Several sedimentary
parasequences were recognized in the Upper Triassic to Upper Jurassic formations exposed on the Templom-hegy: three
fluvio-lacustrine, fining upward parasequences in the Late Triassic; one (or possibly two), marine, fining and deepening
upward parasequences in the Early Jurassic; and a marine sequence, shallowing upward in the Late Jurassic. (The Middle
Jurassic condensed sedimentation will be treated in detail in another paper.) The Late Triassic and Early Jurassic
parasequences (of the Templom-hegy) were deposited in a westward tilted half-graben structure, where the repeated
tectonic movements were responsible for the episodic and cyclic nature of the sedimentation. In the Middle Jurassic the
palaeotectonic regime changed: the faulting ceased and the coherent territory started to sink uniformly. The Mesozoic
subsidence history of the Villány area has close analogies in the contemporaneous blocks of the European inner shelf
domain (e.g. Helvetic, Briançonnais, central Penninic, Czorsztyn, and High Tatric Ridges, Bihor autochthonous). Their
shared features are the intensive subsidence which occurred in the Early and Middle Triassic; then a long interruption of
subsidence in the Late Triassic to Middle Jurassic; this was followed by a renewed, rapid subsidence in the Late Jurassic.
The interrupted subsidence was accompanied by erosion and the formation of half-grabens. This indicates that these
territories belonged to a transpression-transtension dominated zone in mid-Mesozoic times until the opening of the
Valais–Magura oceanic belt.