Structural geological observations in Tölgyhát Quarry (Gerecse Mts, Hungary)

Abstract

The main goal of this paper is to present the results of field investigations carried out in Tölgyhát Quarry, Gerecse
Mts, Transdanubian Range, Hungary. In the outcrop three phases of structural evolution can be detected: (1) E–W
trending dextral strike slip movement with Middle Eocene – late Early Miocene or probably Early Albian – early Middle
Miocene age; (2) reactivation of strike-slip faults as normal fault related to NE–SW extension resulting drag fault
structure probably in late Early – early Middle Miocene age, and (3) listric faulting controlled by E–W tension with
assumed Late Miocene age, but their Pliocene or even Quaternary age can be also suggested. The Toarcian clay suffered
ductile deformation because its low shear strength; both ductile and brittle deformation of Kisgerecse Marl shows its
middle shear strength. Stress resulted only brittle deformation in other calcareous formations of Tölgyhát Quarry. The
models describing the deformation process of normal fault related structures are based on block rotation related to
antitethic normal faulting.