PÓŁWYSEP HELSKI (HEL PENINSULA)



Commune: Władysławowo (pow. pucki, woj. pomorskie)

Framework element or context represented:
The coastal zone of the Baltic Sea.

Primary geological/geomorphological interest:
The relief and the geological evidence of the peninsula.

Comparative assessment justification:
The Hel Peninsula is an important element of the Polish coastline, linking the subaerial and the subaquatic parts of the coastal zone.

Protection status and accessibility:
This area of the geosite-sets is protected since 1978 as the Nadmorski Landscape Park.

Character of site: Sea-coast.

Area: 7452 ha

Altitude: 0 - 3 m a.s.l.

Lithology: sands, peats

Discipline: Geomorphology, Stratigraphy of Quaternary

Process Age: Quaternary, *all periods

Bedrock Age: Quaternary, *all periods




Description of primary interest:
This area is situated within the range of the youngest, Vistulian (Weichselian) Glaciation. The peninsula overlies an exceptionally thick sequence of over 100 m Holocene deposits. The deeper substratum of the Hel Peninsula is formed by Mesozoic rocks. The Pleistocene is represented mainly by fluvial sands. Tills are restricted to a few non-continuous beds, making determination of their age rather difficult. In the eastern part of the peninsula the Holocene sequence is fully developed, reaching a thickness of 100 m. In the western part only a 10-12 m thick bed of marine deposits is found, resting on a thin biogenic, terrestrial bed from the Late Atlantic period. Holocene deposits in the eastern part of the peninsula are subdivided on the basis of biostratigraphic and sedimentological investigations. Pre-Ancylus, Mastogloia, Littorina and Post-Littorina sediments have been identified. The evolution of the peninsula proceeded differently in its western and eastern parts. The western part is genetically terrestrial in origin, peat was formed on the land surface only 6900 a BP. This peat is now 8-11 m below mean sea level and has been radiocarbon dated at several sites. The land was inundated during the final stage of the Littorina transgression. Simultaneously, intensive accumulation took place during the whole Holocene in the eastern part of the peninsula. First freshwater and later marine sediments were transported by currents from the west and deposited on the western slope of the Gdańsk Deep. Hel Peninsula took its present form about 1000 BP, when the sea level rose by about 1.5 m and reached its present height.

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.     GRANICZNY M., JANICKI T., KOWALSKI Z., UŚCIANOWICZ S., ZACHOWICZ J. 2004–Geoindicators of the coastal zone - registration and analisis of processes and phenomena (English sum.). Przegląd Geol. 52, 1: 47-54.     TOMCZAK A. 1993–The Hel Peninsula: relief, geology, evolution. Guide-Book of the excursion. The Baltic IIth Marine Geol. Conf., 17-20. Sopot.     TOMCZAK A. 1995–Relief, geology and evolution of the Hel Spit. In: Polish Coast: Past, Present and Future. Spec. Issue, CERF, 22: 181-185.     TOMCZAK A., KRAMARSKA R., KRZYMIŃSKA J., ZABOROWSKA K., ZACHOWICZ J. 1990–Nowy otwór wiertniczy w Helu w świetle badarń litologicznych, biostratygraficznych i radioweglowych (Polish only). Kwart. Geol., 34(4): 786-787.