Geological Setting of the Shale Gas in Polish Carpathians
The Carpathians define an extensive mountain arc, which stretches at a distance of more than 1 300 km, from Vienna area in Austria, to the Iron Gate on the Danube in Romania. To the west, the Carpathians are linked with the Eastern Alps whereas to the east, they continue into the Balkan mountain chain. Traditionally, the Carpathians are subdivided into their western and eastern parts. The West Carpathians consist of an older, internal orogenic zone known as the Inner or Central Carpathians and the external, younger one, known as the Outer or Flysch Carpathians. The Polish Carpathians form the northern part of the West Carpathians from between Czech and Ukrainian borders. The Carpathian overthrust forms the northern boundary. Southern goes along the Poland-Slovakia state border. The Outer Carpathians are built up of a stack of nappes and thrust-sheets showing a different lithostratigraphy and tectonic structures. The Outer Carpathians nappes thrust upon over other and on the North European Platform and its Miocene -Paleocene cover. The rocks represent a time span between the Late Jurassic and the Early Miocene. They correspond to more or less separate sedimentary basins and every basin generally displays a different lithostratigraphic development. During the overthrusting movements the tectonic units became uprooted and generally only the central parts of the basins are preserved. The following Outer Carpathian nappes have been distinguished: Magura Nappe, Fore-Magura group of nappes, Silesian, Subsilesian and Skole nappes. The Silesian and Skole nappes contain organic-rich rocks. These rocks were deposited during the favorable conditions for organic-richness. The major processes responsible for such richness are: high biologic productivity, non-dilution of organic richness by clastic sedimentation, and preservation of organic matter within its depositional environment. The older rocks we deposited during Early Cretaceous, the younger during Oligocene times. Parts of the anoxic shales have been hidden at the depth of few thousand meters during the folding and overthrusting movements. They can represent unconventional resources known as shale-gas and shale-oil. The older rocks we deposited during Early Cretaceous, the younger during Oligocene times. This research has been financially supported by AGH University of Science and Technology in Krakow grant no. AGH 188.8.131.52 and National Centre for Research and Development grant no. BG2/ShaleCarp/14.
AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017