The Miocene deep-seated spontaneous coal-seam fire in the Upper Silesian Coal Basin (S Poland) and its geotectonic trigger mechanism

The deep-seated spontaneous coal-seam fire occurred in the southwestern part of the Upper Silesian Coal Basin (S Poland), confirmed by oxygenated compounds emission to over- and underlying rocks. The fire was dated at 19.2-19.8 Ma using the Ar-39-Ar-40 method and palaeomagnetism. It was initiated in the Carpathian foreland thanks to a normal faulting in response to thrust-loaded deflections of the Carpathian foreland lithosphere during collision of tectonic plates (Alcapa and stable Europe). The orogenic loading caused this normal faulting in the foreland and triggering the flexural mechanism of foredeep subsidence and forebulge uplift. Thanks to the dating of rocks affected by the spontaneous coal fire initiated during the rapid uplift of coal-bearing rocks, when they became exposed to the aeration zone, the age of these mountain-building processes in the Carpathians has been precisely defined.