ZAGŁĘBIENIE SZESZUPY (SZESZUPA DEPRESSION)



Commune: Rutka-Tartak (pow. suwalski, woj. podlaskie)

Framework element or context represented:
Pleistocene ice-sheet sediments and Holocene landforms.

Primary geological/geomorphological interest:
The landscape generated by Pleistocene and Holocene processes.

Comparative assessment justification:
The Szeszupa Depression represents a most beautiful landscape in the north-eastern part of Poland.

Protection status and accessibility:
The area is protected since 1976 in the Suwałki Landscape Park (6284 ha) which represents high scientific values as well as good sightseeing accessibility.

Character of site: Postglacial relief.

Area: 5000 ha

Altitude: 135 - 230 m a.s.l.

Lithology: tills

Discipline: Geomorphology, Stratigraphy of Quaternary

Process Age: Quaternary, *all periods

Bedrock Age: Quaternary, *all periods




Description of primary interest:
This area of sites-sets is situated within the limits of the youngest, Vistulian (Weichselian) Glaciation. The Szeszupa Depression covers an area of about 50 km2 and lies in the hinterland of the moraines of the Pomeranian Phase of the Vistulian Glaciation. In this region the thickness of Quaternary deposits is between 200-290 m. Detailed investigations of the Szeszupa depression have been carried out. It seems that this depression, similar to the near-by through of Hańcza, the deepest Polish lake (108.5 m), already existed by the end of the Warta (Saale) Glaciation. The depression was probably formed by tectonic, erosional, and glaciotectonic processes. Therefore, the ice-sheets of the Vistulian Glaciation entered the already lowered area, in which consolidated blocks of dead-ice remained longer than on the plateau. The area was incessantly ice-covered by the Vistulian ice-sheet throughout the entire Pomeranian Phase. During its retreat the ice-front must have stagnated for some time in the area of the southern edge of the Szeszupa Depression, and at the same time the position of the ice-front underwent some minor oscillations, which led to the formation of partly disturbed end moraine landforms, lying above the edge of the depression. The present beautiful landscape of the depression with its numerous hills and kettle holes was formed during the Holocene. Some of the kettle holes are now occupied by lakes.

Literature:

BER A. 1974–The Quaternary of the Suwaiki Lake District. Biul. Inst. Geol., 269: 23-105.     BER A. 1999–Preliminary list of the Quaternary geosites in Northern and Central Poland, their age and geological position. Pol. Geol. Inst., Spec. Papers, 2: 77-85.     BER A. 2001–Ważne czwartorzędowe stanowiska geologiczne Polski północnej i środkowej (Polish only). In: W trosce o Ziemię. Księga ku czci Prof. S. Kozłowskiego: 224-239. KUL Lublin.     BER A., KRZYWICKI T. 1995–Smolniki - panoramic view of the Szeszupa depression originating from the Warta Glaciation, relative height: 70 m. XIV INQUA. Intern. Congr., München, 1995, 1: 140-141.     BER A., MAKSIAK S. 1969–Marginal structures and dead-ice structures in the Szeszupa Depression of the Suwałki Lake District. Biul. Inst. Geol., 220: 347-359.     BOGUCKI M. 1985–Budowa geologiczna i ukształtowanie powierzchni (Polish only). In: Stasiak A. Województwo suwalskie, studia i materiały 1: 11-58. Ośrodek Badań Naukowych, Białystok.     SOKOŁOWSKI A.W., KOT J. 1996–Przyroda województwa suwalskiego (Polish only). Wyd. Urz. Woj. w Suwałkach. Suwałki, pp 176.