Commune: Przedbórz (pow. radomszczański, woj. łódzkie) , Kluczewsko (pow. włoszczowski, woj. świętokrzyskie)
Framework element or context represented:
Jurassic and Cretaceous rocks in the western margin of the Świętokrzyskie (Holy Cross) Mts.
Primary geological/geomorphological interest:
Lithostratigraphy and tectonics reflected in morphology.
Comparative assessment justification:
The only site in Poland, where lithostratigraphy and tectonics of the Lower Cretaceous rocks is apparently reflected in the landscape.
Protection status and accessibility:
Przedborski Landscape Park (since 1988), two nature reserves: Murawy Dobromierskie (1989) and Bukowa Góra II (1959) – area well accessible with roads and touristic trails.
Character of site: Hill range with geological outcrops.
Area: 8000 ha
Altitude: 190 - 348 m a.s.l.
Lithology: sandstones, conglomerates, breccias, other siliceous rocks, limestones, marls, sands, silts, clays
Discipline: Geomorphology, Stratigraphy of Phanerozoic, Tectonics
Process Age: *all periods
Bedrock Age: Cretaceous, Jurassic, *all periods
Description of primary interest:
Specific tectonic structure and lithostratigraphy of the Upper Jurassic and Cretaceous sedimentary rocks of the Dobromierz Brachyanticline (and its vicinity) are reflected in morphology of the western segment of the Przedborsko-Małogoskie Range. The area presents also the Jurassic/Cretaceous contact and sequence of rocks illustrating evolution of the Mid-Polish Trough during the Upper Jurassic and Cretaceous. Kimmeridgian is represented with bedded, pelitic, oolitic and onkolitic limestones intercalated by oyster coquinas (Skórków Lumachelle) and overlain by clays (Top Clays). The Jurassic-Cretaceous contact and Cretaceous sequence cropped out in Przedbórz site. The Upper Albian sequence is composed of: 1) basal conglomerate and glauconitic sandstones, 2) varicoloured sandstones (the only rocks exposed in Przedbórz now), 3) white, siliceous sandstones grading to spongiolites and gaises, 4) sandstones with differentiated amount of siliceous cement, partly glauconitic. Cenomanian is represented with glauconitic sands and clays, whereas Turonian – with sandy marls and limestones. Upper Kimmeridgian clayey-carbonate rocks are less resistant, what causes that in the flanks of the brachyanticline harder Albian sandstones build hills distinctly accented in the landscape, with steep slopes without soil cover in places (Krzemycza Mt). The highest hills of the Przedborsko-Małogoskie Range (Suche Góry Mt) are featured by two-step morphology of slopes. Their highest ridges (ca 120 m above the plain) are formed of the Albian sandstones, whereas the lower flattenings on the slopes are built of the Upper Jurassic rocks and dissected with dried valleys.
Literature:
BARWICZ-PISKORZ W 1995–Foraminiferal assemblages and stratigraphy of Upper Jurassic in the Holy Cross Mts. District (English sum.). Rozprawy. Monografie (AGH) 21, 147 pp. CIEŚLIŃSKI S. 1956–Stratigraphy and tectonics of the Cretaceous between Dobromierz, Józefów and Przedbórz on the Pilica (Middle Poland) (English sum.). Biul. Inst. Geol. 113: 139-194. CIEŚLIŃSKI S. 1976–Development of the Danish-Polish furrow in the Góry Świętokrzyskie Region in the Albian, Cenomanian and Lower Turonian (English sum.). Biul. Inst. Geol. 295: 249-269. CIEŚLIŃSKI S., POŻARYSKI W. 1970–Cretaceous (English sum.). Prace Inst, Geol. 56 (The stratigraphy of the Mesozoic in the margin of the Góry Świętokrzyskie): 185-231. HAKENBERG M., ŚWIDROWSKA J. 1998–Evolution of the Holy Cross Mts segment of the Mid Polish Trough during the Cretaceous. Kwart. Geol. 42, 3: 239-262. KUTEK J. 1967–Remarks on the Middle Cretaceous stratigraphy in the vicinity of Przedbórz and Radomsko (English sum.). Biul. Geol. Wydz. Geol. Uniw. Warsz. 9: 273-288. KUTEK J. 1968–The Kimmeridgian and uppermost Oxfordian in the SW part Of the Holy Cross Mts (Central Poland). Part. I. Stratigraphy (English sum.). Acta Geol. Pol. 18, 3: 493-586. KUTEK J., MATYJA B. A., WIERZBOWSKI A. 1992–The Holy Cross Mts., introduction In: Oxfordian and Kimmeridgian Joint Working Group Meeting. Warszawa and Central Polish Uplands, 7-12.09.1992. Intern. Subcomm. on Jurassic Stratigr., Warszawa. Guidebook and Abstracts: 22-26. WALASZCZYK I., CIEŚLIŃSKI S., SYLWESTRZAK H. 1999–Selected geosites of Cretaceous deposits in Central and Eastern Poland. Pol. Geol. Inst. Special Papers 2: 71-76.