NISKOWA W KOTLINIE SĄDECKIEJ (NISKOWA IN SĄCZ BASIN)



Commune: Chełmiec (pow. nowosądecki, woj. małopolskie)

Framework element or context represented:
Litho- and biostratigraphy of Carpathian Miocene deposits.

Primary geological/geomorphological interest:
Sequence of Miocene sediments representative for the Sącz Basin - Carpathian intramountain depression.

Comparative assessment justification:
The complete litho- and biostratigraphic sequence of the Miocene Niskowa Fm sediments fills the intra-Carpathian depression called Sącz Basin. The second stratotype of Miocene sediments crop out in SE part of basin and is represented by the Biegonice Fm.

Protection status and accessibility:
Proposed documentary site.

Character of site: Natural outcrops.

Area: about 0.2 ha

Altitude: 330-390 m a.s.l.

Lithology: silts, clays

Discipline: Palaeobiology, Palaeoenvironment, Stratigraphy of Phanerozoic

Process Age: Pleistocene, *all periods

Bedrock Age: Neogene, *all periods




Description of primary interest:
The Sącz Basin is an intramountain tectonic depression (225 km2) of the area joint of two important Carpathian valleys of Dunajec and Poprad rivers. Neogene and Quaternary (Pleistocene and Holocene) deposits cover the background with folded flysch of Magura Unit. The Neogene sediments represented by two lithostratigraphic formations crop out in central part of the basin. One of them Biegonice Formation is composed of mainly terrestrial sediments and second – Niskowa Formation encloses the brackish and marine deposits. The most representative locality of Miocene sequence is situated at Niskowa in the western part of the Sącz Basin. These are natural outcrops along both sides of Pruska stream. The sequence begins with grey clays and mud containing plant remains and a layer of brown cool used by a small mine just at the end of XIX century. They pass upward into clays abounding in shells of Cerithium in addition of few other species of snails, bivalves, foraminifera and fish otoliths. This biota indicates the brackish marine environment. The Cerithium clays are the faciostratotype of the Iwkowa Formation. Thin-grained sand locally cemented represents the upper part of the sequence. They contain relatively rich fauna of molluscs, foraminifera, corals, bryozoans, brachiopods and ostracods, accompanied by remain of green algae. These are sediments typical of a shallow-marine environment, indicated as the stratotype of the Niskowa Formation. The Neogene deposits in the Sącz Basin have a long tradition of investigations attaining the XIX century.

Literature:

ALEXANDROWICZ S.W. 1974–Mikrofauna osadów miocenu z Niskowej koło Nowego Sącza (Polish only).  Kwart. Geol. AGH 18, 4: 937-939.     ALEXANDROWICZ Z. (ed), MARGIELEWSKI W., URBAN J., GONERA M. 1996–Geoconservation of the Beskid Sądecki and the Sącz Basin, Polish Carpathians (English sum.). Studia Naturae 42: 1-148.     BAŁUK W. 1970–The Lower Tortonian at Niskowa near Nowy Sącz, Polish Carpathians. Acta Geol. Pol. 20, 1: 101-150.     CIESZKOWSKI M. 1977–Fragments of calcite petrified trunks of Miocene trees from Niskowa near Nowy Sącz (English sum.). Przegląd Geol. 7: 389-390.     CIESZKOWSKI M., GONERA M., OSZCZYPKO N., ZUCHIEWICZ W. 1988–Lithostratigraphy and age of Upper Miocene deposits at Iwkowa, Polish West Carpathians. Biul. Pol. Acad. Sci., Earth Sci. 36, 3-4: 309-329.     MAŁECKI J. 1970–Chlorophyta from Miocene sediments of Poland (English sum.). Rocz. Pol. Tow. Geol. 40, 1: 167-173.     OSZCZYPKO N. 1970–The geology of the Nowy Sącz Basin, the Middle Carpathians (English sum.). Biul. Inst. Geol. 271. Z Badań Geol. w Karpatach 17: 101-197.     SKOCZYLASÓWNA K. 1930–Beitrag zur Kenntnis der Miozanablagerungen in der Umgebung von Nowy Sącz (German sum.). Rocz. Pol. Tow. Geol. 6: 50-72.     ŚMIGIELSKA T. 1973–Fish otoliths from the Lower Tortonian deposits at Niskowa near Nowy Sącz. Rocz. Pol. Tow. Geol. 43, 1: 3-37.