Commune: Krzeszowice (pow. krakowski, woj. małopolskie)
Framework element or context represented:
Quaternary stratigraphy and paleoenvironment.
Primary geological/geomorphological interest:
A sequence of dated, mollusc-bearing Holocene calcareous deposits.
Comparative assessment justification:
The sequence of Holocene calcareous sediments and assemblages of molluscs, typical of Poland, one of the most important in Europe. Three outcrops in the Cracow Upland and one in the Holly Cross Mts. - less representative. A few sites in Czech Rep., Slovakia and Ukraine.
Protection status and accessibility:
Outcrop in the nature reserve.
Character of site: Escarpes of river terraces.
Area: 2 ha
Altitude: 300 m a.s.l.
Lithology: limestones, gravels, silts, clays, other sedimentary rocks
Discipline: Geomorphology, Palaeoenvironment, Stratigraphy of Quaternary
Process Age: Quaternary, *all periods
Bedrock Age: Quaternary, *all periods
Description of primary interest:
The Racławka stream valley in its middle reach deeply dissects Lower Carboniferous limestones. Holocene travertine and calcareous tufa locally form the terrace up to 10 m high. The main outcrop situated on the left bank of the stream encloses two types of calcareous deposits: the bioherm forming a barrier and tufa composed of fine- and coarse-grained material with intercalations of limestone gravel, organic mud and fossil soil. Radiocarbon dating indicates, that the mentioned sediments accumulated during the interval of 10–1,5 thousand years BP. Very rich assemblages of molluscs occur in calcareous tufa. They contain species typical of particular climatic phases of the Holocene and reflect the human impact during the Late Holocene. Calcareous deposits became eroded at the Early Medieval and the 10 m terrace originated. The referred outcrop is the representative site of Holocene tufa and travertines of Poland documenting changes of the environment during the last ten thousand years.
Literature:
ALEXANDROWICZ S.W. 1983–Malacofauna of Holocene calcareous sediments of the Cracow Upland. Acta Geol. Pol., 33: 117-158. ALEXANDROWICZ S.W. 1999–Protection of Holocene travertines in Southern Poland. Mem. Descr. Carta Geol. d'Italia 54: 67-72. PAZDUR A., PAZDUR M., STARKEL L., SZULC J. 1988–Stable isotope of the Holocene calcareous tufa in S-Poland as paleoclimatic indicators. Quat. Res. 30: 177-189. RUTKOWSKI J. 1991–Holocen doliny Dolnej Racławki. Geologia AGH 17: 173-191. SZULC J. 1986–Holocene travertine deposits of the Cracow Upland. In: IAS 7-th Europea Meeting. Ex Book: 185-189.