OZ TURTULSKI (TURTUL ESKER)



Commune: Jeleniewo (pow. suwalski, woj. podlaskie)

Framework element or context represented:
Pleistocene landforms.

Primary geological/geomorphological interest:
The relief and structure of esker.

Comparative assessment justification:
The exceptional example of the well developed esker.

Protection status and accessibility:
The Turtul esker is protected within the Suwalski Landscape Park and represents high scientific values and a good sightseeing accessibility.

Character of site: Glacial landform.

Area: ca. 80 ha

Altitude: 199 - 210 m a.s.l.

Lithology: gravels, sands, silts, clays

Discipline: Geomorphology, Stratigraphy of Quaternary

Process Age: Quaternary, *all periods

Bedrock Age: Quaternary, *all periods




Description of primary interest:
The Turtul esker is situated within the limits of the youngest, Vistulian (Weichselian) Glaciation in the 4 km long, 150-250 m wide and 30 m deep, steep-sided (up to 35°), flat-floored Czarna Hańcza valley. The esker forms a range extending over a distance of 3 km. The north-western part of the esker occurs within a somewhat shallower and broader section of the valley. Farther, the esker enters the narrower deeper and steeper-sided lower part of the Czarna Hańcza valley, that widens only in its terminal part, near its mouth, which being here barred by the dam of the Turtul mill is occupied by a pond. The first fragment of the esker is a small hill. In profile, beneath a thin, structurelless, gravel-stony cover is a succession of silts, sands and gravels, both fine- and coarse-grained, exhibiting diagonal- and cross-stratification as well as an outward dip of the layers. The second fragment forms a 600 m long and 10m high ridge composed of the deposits similarly bedded though underlying a thicker (2 m) structureless cover (mainly sand). The third component of the esker is a short (180 m) asymmetrical ridge consisting of coarse limestone gravel interbedded with sands. The fourth component is a 300 m long ridge rising up to 18 m above river level and has the steepest slopes (ca. 35°) and the most regular structure i.e., a diagonal, distal stratification of sands, with layers dipping toward the esker slopes. The fifth element consists of a lower ridge, equalling in dimensions of the second element. All other elements of the esker partly submerged by the pond, consist merely of small, elongated hills built of stratified gravels and sands.

Literature:

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.     CZERNICKA-CHODKOWSKA D. 1991–Formy ozowe na obszarze Polski (Polish only). Katalog: 1-150. Muzeum Ziemi PAN, Warszawa.     PIETKIEWICZ S. 1928–Pojezierze Suwalszczyzny Zachodniej. Zarys morfologii lodowcowej. Prz. Geogr., 8: 168-222.      PIETKIEWICZ S. 1961–Turtul. The Turtui esker and the surrounding subglacial drainage system. IV INQUA. Intern. Congr. Guide Book of Excursion D. North-East Poland, 56-58.      PIETKIEWICZ S. 1977–Turtul Esker (English sum.). Stud. Geol. Pol., 52: 361-372.