Commune: Daleszyce (pow. kielecki, woj. świętokrzyskie)
Framework element or context represented:
Condensed sequence of the Middle Ordovician of Kielce subregion of the Świętokrzyskie (Holy Cross) Mts belonging to the Małopolska Caledonian massif.
Primary geological/geomorphological interest:
Stratotype of Mójcza Limestones Formation, paleontological site.
Comparative assessment justification:
The site is the only outcrop of full sequence of the Ordovician limestones (not metamorphised) in the region and in Poland; well exposed, periodically uncovered and adapted for scientific and educational use.
Protection status and accessibility:
Proposed for protection – well accessible, situated near Kielce town.
Character of site: Outcrop in old, small quarry.
Area: 0.01 ha
Altitude: 285 m a.s.l
Lithology: sandstones, limestones, marls, shales
Discipline: Palaeobiology, Palaeoenvironment, Stratigraphy of Phanerozoic
Process Age: *all periods
Bedrock Age: Ordovician, *all periods
Description of primary interest:
Artificial outcrop of the condensed sequence of the Ordovician. The lowermost part of the succession (now not exposed) represents upper part of the Bukówka Sandstone Fm, which passes to the Mójcza Limestones Fm (outcropped, dip 50º to NE). The Mójcza Limestones Fm (Upper Arenig-Upper Caradoc), is 8,5 m thick and stratigraphically almost continuous, with one gap (between Arenig and Llandvirn). It is formed of biodetritic and oolithic limestones – grainstones, in the upper part – packstones to wackestones. In the middle part bentonite horizon of correlative importance occurs. Bioclasts are represented with ostracods, crinoids, brachiopods, bryozoa, trilobites and molluscs. New taxa of trilobites, ostracods, molluscs and conodonts were described here. The bioclasts are often coated with calcite or phosphatic envelopes. Ooids are formed of calcite or iron oxides, which also represent significant components of upper part of the formation. Above the Mójcza Fm occur: a) marly limestones and marls (1,8 m) of Zalesie Fm, b) thin layer of sandy marl with mixed Ordovician and Silurian conodonts (what suggests lack of uppermost Ashgil and Llandovery), c) Silurian Bardo Formation - shales with limestone inserts (not exposed now). The Mójcza Fm was deposited in stable environments on submerged platform separated from the source of terrestial material and represents mainly the first stage of carbonate sedimentation during Ordovician related to sea-level highstand after Llandwirn transgression. The second stage (Mójcza Fm and Zalesie Fm) is related to the next trangression and sea level highstand.
Literature:
BEDNARCZYK W. 1981–Stratygrafia ordowiku Gór Świętokrzyskich (in Polish only). In: Przew. 53 Zjazdu Pol. Tow. Geol., Kielce: 35-41. DZIK J. 1999–Excursion I, day, stop 1: Mójcza. In: Dzik J., Linnemann, Heuse T. (eds), Intern. Symp. on the Ordovician System, ISOS Prague 1999, Excursion guide – Poland and Germany: 8-10. DZIK J., OLEMPSKA E., PISERA A. (eds) 1994–Ordovician carbonate platform ecosystem of the Holy Cross Mts. Palaeont. Pol., 53, part 1, 317 pp, part 2, 136 pp. MODLIŃSKI Z., SZYMAŃSKI B. 2001–The Ordovician stratigraphy and palaeogeography of the Nida-Holy Cross Mts area, Poland – a rewiev. Geol. Qater. 45, 4: 417-433. MODLIŃSKI Z., SZYMAŃSKI B. 2001–The Silurian of the Nida, Holy Cross Mts and Radom areas, Poland – a review. Geol. Qater. 45, 4: 435-454. OLEMPSKA E. 1988–Mojczella, a new genus of Ostracoda from the Ordovician of the Holy Cross Mts., Poland. Acta Palaeont. Pol. 33: 135-144. TRELA W. 1998–Sedimentary environment of the condensed Ordovician limestones from Mójcza section (Holy Cross Mts.). Geol. Quater., 42, 3: 289-300. TRELA W. 1999–Ferruginous ooids and ironstones in the Ordovician section from the Holy Cross Mts (central Poland) (English sum.). Przegl. Geol. 47, 2: 181-186. TRELA W. 2002–Controls on development of the carbonate sedimentation in the Ordovician of the Kielce region. Holy Cross Mts) (Polish only). Przegl. Geol. 50, 12: 1223-1224. TRELA W. 2002–Rozwój sedymentacji węglanowej w środkowym i górnym ordowiku w regionie kieleckim Gór Świętokrzyskich (Polish only). Posiedz. Nauk. Pol. Inst. Geol. 58 (10): 104-107.