The Silesian Beskid is part of a great geological unit, related. Outer Carpathians, mainly composed of alternating layers of sandstone, conglomerates and slates as well as minor marls and limestones. These rocks were formed at the bottom of the Mediterranean Sea, occupying then (ok. 140-35 mln. years ago) pd. areas of present-day Poland. The seabed and the surrounding land were in constant motion. After a strong uplift of land, coarse-grained sediments accumulated on the seabed, from which conglomerates and coarse-grained sandstones were formed. As land declines due to erosion, finer and finer material flowed into the sea, from which fine-grained sandstones were formed, clay shales, etc.. Calcareous shells and skeletons of sea animals settling on the bottom or calcite precipitating from sea water gave rise to marls and limestones. All these clearly grounded rocks are collectively called Carpathian flysch.
During the great intensification of orogenesis of the Alpine orogeny at the turn of the Paleogene and Neogene, i.e.. ok. 25 min years ago, flysch sediments reaching a thickness of several thousand meters were folded. These folds under pressure from the South. were then overthrown, torn off the ground and shifted to the north., creating great tectonic units called. coat us. The size of one mantle overlapping another is 20-30 km.
Originally, the sediments that formed on the seabed were arranged in almost horizontal layers, younger to older. During folding, the rocks are the most plastic, especially clay shales, were easier to bend and squeeze. Rather, the stiff shoals of sandstone broke into large slabs and overlapped each other, separating from those lying below, slippery slate layers.
Almost the entire area described in this guidebook, with the exception of the Girowa * massif and the adjacent part of Polish territory to the south. from Istebna * is located within the Nappe, called. Silesia. It can be distinguished by the lower so-called. Cieszyn Nappe, made of various types of slate and limestone, and higher, the so-called. the godul mantle, mainly made of thick series of sandstones and conglomerates. These rocks, with a thickness of several thousand meters, made the Godul nape significant stiffness: during tectonic movements it was "pricked" (split off) from the lower Cieszyn Nappe. Then the Godul nape was slid flat over the soft layers of the Cieszyn nappe, which undergo intensive folding at the same time.
The Cieszyn coat of arms builds almost the entire Cieszyn Foothills. Dark gray, soft and coarse splitting. lower Cieszyn shales, easy to observe in the streams to the north. from the Puńców * line – Cisownica *, are the oldest sedimentary rocks of the flysch Carpathians. Sometimes there are inserts of dark gray limestone among them, cut with veins of white calcite. In the upper Cieszyn slates there were counts 26 thin shoals of clay siderites, operated until mid. ub. century (m.in. in Nydek *, Punts *, Upper and Lower Leszna *, Cisownica * and Ustroń *) as iron ore for local smelters (16C). Most of the "Kępa" in the Cieszyn Foothills - not high hills, such as Chełm *, Jasieniowa *, Jelenica *, Thulium*, Wróżna * or Babia Góra * is built of more resistant Cieszyn limestones. The thickness of their individual shoals reaches up to 3,5 m. They were exploited in numerous quarries for burning lime and for making cement, and now as a building stone (1S, 18WITH). In Puńców *, Dziegielowie *, Cisownicy* i in. there are outcrops of dark colored igneous rocks, related. Cieszynites. They usually appear as thick veins, undulating with the surrounding rocks.
You pn. Further layers of rocks appear at the foot of the Silesian Beskids: Wierzowska shales and the so-called. Grodzisk and Igockie layers. They constitute the lowest link of the Godul nape and build the two lowest sills to the north. mountain slopes, visible on Ostry * and pn. slopes of Mł. Czantorii*. Third, a much higher degree is marked by the peaks of Mała Czantoria * to the west. the Vistula bank and Lipowski Groń on the eastern bank. It is built by rocks of the lower Godul layers: the so-called. the lower branch is thick-bedded, coarse-grained, calcareous sandstones with a gray-blue color in a fresh breakthrough, whitish and fine after weathering- and medium-grained agglomerates (visible in the quarries in Obłaździec * and Poniwiec *, 3N), while the higher unit is thin-bedded, fine-grained greenish glauconite sandstones, layered with green slate and mudstones (visible e.g.. in the valley of the Suchy Stream *, 4C, or at the mouth of the Jawornik valley *, 6N).
The highest peaks of the border ridge from the UK. Czantoria * after Cieślar * build thick- and mid-lane, medium- and fine-grained sandstones, greenish tint due to the content of glauconite grains, interleaved with gray-green slates. They are included in the name of the middle godul layers. On the other hand, the UK. The cone * and the slopes surrounding the Vistula valley * build thick-lava flows, fractionally grained, Mica-feldspar sandstones of gray-green color, already included in the upper Godul strata. The same rocks build most of the arm of Łączka * and Filipki *.
The Godul mantle is only slightly folded, and the layers fall to the south. i pd.-zach. A more prominent anticline (the ridge of the fold) runs along the line in Beskid Śląski: Nydek * – Obłaziec * in the Vistula valley * – the center of Brenna – Szczyrk. We can observe here the reversal of the relief characteristic for the flysch mountains: on the anti-wedge line, once uplifted, the long erosion process resulted in a series of valleys and distinct ridge depressions. It runs in the area described here from Nydek * along the Strzelma valley * to the Beskidek pass *, and from here to Obaziec *. In this zone, thin-bedded sandstones have been exposed again, and in places (e.g.. in the quarry in Obłaździec * and on the slopes of Cowshed in the Równica range) - thick-bed sandstones and conglomerates of the lower Godul layers. Further south. the rocks of the middle godul layers reappear, belonging to pd. The "wings" of the anticline.
The higher link of the Godul nape is the so-called. the Istebna layers, upbuilding pd. part of the range in question to the Olza valley * in Jasnowice *. They mainly consist of thick coarse-grained shoals, characteristic quartz-feldspar conglomerates and conglomerate sandstones, rusty color on weathered surfaces; the color and the absence of dark green glauconite grains make it possible to distinguish these rocks from the majority of sandstones of the Godule layers. They build the part of the main ridge of the range from the turn. Kubalonka * through Kiczory * and Kyrkawica * to the ridge of Groniczka *, main frameworks of Kobyla *, Rocky Mountain * and Młodej Góra *, and also, among others. - in the form of an isolated lobe - Praszyna * over Nydek *.
The highest link in the entire Silesian Nappe is a complex of very diverse rocks (a variety of sandstones, slate, hornworms, mudstones etc.), stretching along a narrow strip in the southern. parts of the region concerned. They build the valley of the upper Olza * and the northern part. slopes of the Girowa massif *. In the dark shales of the upper Istebna layers there are deposits of spherosiderites, exploited as iron ore in the 18th-19th centuries. m.in. on the south. from today's center of Istebna *. Among these rocks there are also the so-called. Gródeckie sandstones - myco-glauconite sandstones with a clayey binder, porous after weathering, first described in the second half of. ub. century in Gródek *.
The most southern fragment of the area in question, i.e.. the ridge section of the main Carpathian watershed from Ochodzita (895 m) through Wawrzaczów Groń * and Girowa * up to Przeł. Jabłonkowska * is already included in a separate area, a small geological unit - the so-called. Pre-Magura husk. It is mainly made up of thick-bed sandstones of the Krosno layers. The top parts of Girowa *, on the other hand, are made of thick-bedded ones, coarse-grained sandstones of the Magura series from Heavy Dutykowice.
The so-called. Parachthonous flysch (local), underlining the Cieszyn Nappe. As a result of the erosive activity of the Olza's waters *, this flyer, which consists mainly of various colors („Pstre”) slates with thin sandstone inserts, appears in its valley to the south. as far as Bystrzyca *.