Print this pageMiocene Evaporites of the Carpathian Foredeep Basin - Their Internal Structure and Role in Compressional Tectonics (250 Years Perspective)
Piotr Krzywiec
Polish Geological Institute, Warsaw, Poland
The Miocene Carpathian foredeep basin developed in front of the advancing Carpathian orogenic wedge. Foredeep infill consists of the Eggerian to Sarmatian sedimentary sequence and includes important evaporitic formation. Presently, in front of the Outer Carpathian flysch (pre-Miocene) units, a zone of deformed foredeep deposits exists (the so-called Zglobice unit). Miocene foredeep evaporites have been continuously exploited for over 700 years in the Krakow region, in the Wieliczka and Bochnia salt mines. Earliest published illustrations of tectonic structures of the salt date back to XVIII cent. (Schober, 1750) and show complex folds and thrust deformations. In early XIX cent., in the course of geological studies stimulated by intensified underground salt exploitation, first cross-sections showing relationship between the deformed Miocene salt-bearing succession and the overthrust Carpathian flysch wedge have been published (e.g. Pusch, 1825; Rost, 1840; Murchison, 1845). In post-IIWW times, before wide application of geophysical methods, Tolwinski (1957) summarized state-of-art of geological understanding of the deformed Miocene salt-bearing Carpathian foredeep succession. Recently, due to availability of high-quality 2D and 3D seismic data calibrated by numerous exploration wells, geological studies entered new phase of imaging and analysis of salt compressional tectonics in this region. Rock salt, present between Pilzno and Krakow (Wieliczka), triggered wedge tectonics and led to formation of triangle zones. Lateral variations of structural style of the frontal Carpathian orogenic wedge were controlled by thickness and facies variations of evaporitic succession (rock salt vs. anhydrite) and morphology of the pre-Miocene Mesozoic substratum (lower plate).
AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas