Geological history of the Pieniny Klippen Belt and Middle Jurassic black shales as one of the oldest deposits of this region – stratigraphical position and palaeoenvironmental significance

The main aim of this paper is presentation both general history of the Pieniny Klippen Belt and two famous sites in this region: Dunajec River Gorge and Homole Gorge. According to such general introduction the authors explain also palaeogeographical position of the Pieniny Klippen Belt Basin within Mesozoic Tethyan Ocean, and especially stratigraphical position and palaeoenvironmental conditions of Middle Jurassic black shales and their significance in geodynamic reconstruction of this basin. Both the Dunajec River Gorge, one of the most popular geotouristic object within Pieniny Mts, and Homole Gorge, one of the best place to geological study of the Pieniny Klippen Belt, are most attractive natural phenomena of this geological region.


Selected most famous geological objects in the Pieniny Klippen Belt and their geotouristic values
Rafting trough Dunajec River Gorge One of the major geotouristic attraction of the Pieniny Klippen Belt region is the rafting through the Dunajec River Gorge (Golonka & Krobicki, 2007, see also Alexandrowicz & Alexandrowicz, 2004).The rafting trip on the Dunajec River, which starts at Sromowce Kąty harbour (Figs 8,9), takes geotourist through the Dunajec Gorge to Szczawnica.The Dunajec offers magnificent view of the cliffs sculptured in the Pieniny Mountains by the tectonic activity and river's erosion.It offers also the close view of the outcrops of Jurassic and Cretaceous rocks of the Pieniny Succession and complex tectonics of the PKB.
The Kąty's harbor has good connection with main touristic points in the Pieniny Mts and is easily accessible both from Zakopane (from south) and from Kraków (from north).Kąty are located very close to famous medieval castles (Czorsztyn Castle -Fig.10A and Niedzica Castle -Fig.10B), which occupied good accessible and visible places just above artificial Czorsztyn Lake.
The Macelowa Mt (Fig. 11) is the first viewpoint along our boat trip.The Oxfordian radiolarites and latest Jurassic-Early Cretaceous gray cherty limestones of the Maiolica facies (Pieniny Limestone Formation) of the Pieniny Succession, occupy topmost and middle part of this mountain in completely overturned position.Therefore, the youngest part of this succession occurs in lowest (topographically) position and is represented by the Late Cretaceous Globotruncanabearing marls of the Scaglia Rossa-type deposits (Fig. 11A) (Birkenmajer, 1979;Bąk, 2000).In close view we can see red marls and marly limestones with greyish intercalations of calcareous sandstones and siltstones of turbiditic origin connected with distal parts of submarine fans, typical flysch and flyschoidal sedimentation (comp.Mutti & Ricci Lucchi, 1975;Słomka, 1986;Stow, 1986;Mutti & Normark, 1987;Ghibaudo, 1992;Reading & Richards, 1994;Lowe, 1997;Shanmugam, 2000).The red Globotruncana marls of the Scaglia Rossa-type facies (in local nomenclature -Macelowa Marl Member of the Jaworki Formation; Birkenmajer, 1977), which we can see now, is the youngest part of this unit.The Jaworki Formation is composed (stratigraphically) by green-variegated-red globotruncanid marls with perfect studied biostratigraphy (Bąk, 2000).Such type of facies is wide known both from Alpine and Apennine geology.The primary seaways between several parts of the Tethyan Ocean, especially the above mentioned Alpine Tethys (Golonka, 2004), which existed during the Late Cretaceous times are very well documented by these facies occurrences.Later, Dunajec River crosses through several vertical strike-slip faults, which separate the Pieniny Klippen Belt from the Central Carpathians Palaeogene Flysch region (precisely -Oligocene in age).At Sromowce Niżne village (Figs 8,11) the Dunajec River enters again Pieniny Klippen Belt.
The most famous and beautiful peak of the Pieniny Mts -Trzy Korony Mt (Three Crowns) (982 m a.s.l.) (Fig. 11B) is good visible at the beginning of the Dunajec River Gorge (Birkenmajer et al., 2001).In local, folk nomenclature, the Trzy Korony peak is known as (from left to right): Kaśka (Kate), Zośka (Sophie) and Kudłata Maryśka (Hairy Mary).The very steep walls of this peak are formed by strongly folded thin-bedded, grey, cherty limestones of the Maiolica (=Biancone) facies of the Pieniny Limestone Formation (Kimmeridgian-Albian) of the Pieniny Succession.
The origin of the Dunajec River Gorge is connected with young, mainly Neogene history, related to the neotectonic movements.This river have had the mature stage in the latest Miocene-Pliocene time, and manifested by meandering shape.Then, during episode of the uplifting of the Pieniny Mts, such shape of the river have been conserved, when more competent Late Cretaceous marls and marly limestones, softer than Jurassic/Early Cetaceous cherty limestones, which occurred between several tectonic slices, have been easily eroded by the Dunajec River water, during the fault-related uplift.Origin of strongly faulted, usually thin-bedded Maiolica-type cherty limestones is connected with this tectonic activity of Alpine orogeny (Fig. 11E).Some of the faults were still active during the Quaternary and were connected with rare earthquakes (Baumgart-Kotarba, 1996, 2001;Zuchiewicz et al., 2002 and references therein).Recently vertical movements reached up to + 0.5 mm per year, according to very detail geodetic measurements (Vanko, 1988;Vass, 1998).Detail description of origin and age of the Dunajec River Gorge, with the review of structural and geomorphological features of the Pieniny Mts and formation of magnificent cliffs of the Gorge, was published by Birkenmajer (2006) (see also -Zuchiewicz, 1982).
The next interesting point on the right bank of the Dunajec River is the medieval Czerwony Klasztor (Red Monastery) constructed in 1330, where one of the Camelot's pharmacist (Brother Cyprian -Franciszek Ignacy Jeszke) collected a huge quantity of plants (282 species), both from the Pieniny and Tatra mountains.
The Pieniny Limestone Formation builds steep cliffs along the Dunajec River Gorge, described in more detail by Golonka & Krobicki (2007).One of the most spectacular views along rafting trip is Mnichy (Seven Monks) (Fig. 11C) and Sokolica Mt (Falcon's Mt) (Fig. 11D).The name of this mountain is derived from numerous falcons, which used to nest here.
The Sokolica is frequently visited by hikers because of magnificent view of the Tatra Mts and the ancient, 500 yearsold pine forest (Tłuczek, 2004).Close to the Szczawnica town, the Dunajec River Gorge ended, just after the last cliff built by thin-bedded cherty limestones.This town is popular spa, famous for its mineral springs, which have been known since the medieval time, but first written remarks came from XVI century.
After rafting on Dunajec River we will go eastward to Jaworki village.The Grajcarek stream valley runs parallel with the Pieniny Klippen Belt, where Jurassic and Lower Cretaceous rocks of the so-called tectonic Grajcarek Unit are exposed (with full development of the Magura (Hulina) Succession).This succession was deposited within the northwestern part of the Carpathian Tethys, separated palaeogeographically by the Czorsztyn Ridge from the other basinal succession (Birkenmajer, 1986;Golonka, 2004;Golonka & Krobicki, 2004).On the northern side this unit is in tectonic contact with the flysch rocks of the Krynica Unit of the Magura Nappe.Several Miocene andesite intrusions cut both tectonic units (Malinów abandoned quarry, Jarmuta and Krupianka hills).

Homole Gorge near Jaworki village
The famous deep Homole Gorge is cutting through the rocks of the so-called Homole tectonic block south of the Jaworki village (Figs 8,9,(12)(13)(14).The origin this block is speculative and a subject of scientific debate.There is a variety of opinions, from the autochthonous position within the Czorsztyn ridge (e.g.Birkenmajer, 1986) through the nappe thrust over the other tectonic units (e.g.Książkiewicz, 1977;Golonka & Rączkowski, 1984;Jurewicz, 1997Jurewicz, , 2005) ) to the olistoliths (Cieszkowski & Golonka, 2005, 2006;Cieszkowski et al., 2008).In the Homole Gorge up to near 100 m thick section of white crinoidal limestones of the Smolegowa Limestone Formation of the Czorsztyn Succession is exposed (Birkenmajer, 1963(Birkenmajer, , 1977)).These limestones are overlain by red crinoidal limestones (of the Krupianka Limestone Formation) and Ammonitico Rosso-type nodular limestones of the Czorsztyn Limestone Formation, which reach maximum 20 m in thickness.Both Smolegowa and Krupianka formations are Bajocian (Middle Jurassic) in age whereas condensed nodular limestones of the Ammonitico Rosso facies (Czorsztyn Limestone Formation) represent Middle Jurassic to Early Cretaceous.The decrease of sedimentation rate in pelagic sedimentation regime happened during late Middle-Late Jurassic times.This phenomenon is recorded by the deepening-upward sequence of deposits.The famous Pieniny Klippen Belt tectonic fold and thrust structures can be observed in the Czajakowa Skała Klippe in the upper part of the Homole Gorge (Birkenmajer, 1970(Birkenmajer, , 1979) (Fig. 12D).The Niedzica Nappe is there thrust here over the thick Czorsztyn Unit.Several beds representing the red nodular limestones of the Ammonitico Rosso-type of the Niedzica Limestone Formation and Czorsztyn Limestone Formation as well as intercalated radiolarites of the Czajakowa Radiolarite Formation are strongly tectonically disturbed, forming the overturned fold (Birkenmajer, 1970;Jurewicz, 1994) (Fig. 12D).The type locality of the Czajakowa Radiolarite Formation occurs within this klippe (Fig. 13).The Czajakowa Skała Klippe also shows a complete sequence of the Jurassic deposits of the Niedzica Succession (Birkenmajer, 1977;Wierzbowski et al., 1999).The oldest black and grey marly shales with spherosiderite concretions of the Skrzypny Shale Formation (Birkenmajer, 1977;Tyszka, 1994) are exposed here.These deposits are overlain by yellowish-greyish-red and dark cherry-greenish crinoidal limestones.The contact between black shales and crinoidal limestones is sharp and irregular.The ammonite fauna was found in the lowermost part of the crinoidal limestones of the Smolegowa Limestone Formation.These very precise biostratigraphical data suggest a hiatus between black shales and crinoidal limestones, spanning the Laeviuscula and a part of Propinquans ammonite zones of the Lower Bajocian (Middle Jurassic) (Krobicki & Wierzbowski, 2004;Krobicki, 2006).The small outcrops of these black shales occur below Czajakowa Skała Klippe within local landslide.The best outcrops of these rocks within the Pieniny Klippen Belt in Poland occur in the Krupianka stream, which run the Homole Gorge, westward.Their thickness reach 4-5 metres.The shales contain a lot of spherosiderites and sometimes perfectly preserved ammonites (Fig. 14).The ammonite fauna indicates latest of Aalenian and/or earliest of Bajocian (Middle Jurassic) age of black shales, representing oxygendepleted facies of the Fleckenmergel-type. This research has been financially supported by AGH grant (11.11.140.447)