Callovian crinoidal sandstone from North East Świętokrzyskie Mts. (Central Poland)

• Autorzy: Ostrowski S.
• Konferencja: International Congress on the Jurassic System (7 ; 06-18.09.2006 ; Kraków, Poland)
• Języki publikacji: EN

Abstrakty

EN

Monotonous calcareous sandstones outcropping on the northern slopes of Kamienna River North East Świętokrzyskie Mts. (Holy Cross Mts.) are recognized as Callovian mostly on the basis of superposition (Samsonowicz 1932) and scarce occurrence of ammonites Macrocephalites and belemnites. Although the rocks are exploited for over 200 years, there is no complete sedimentological study available. Outcropping rocks are yellow and brown, quartz-calcareous sandstones, poorly horizontally bedded. Cross-bedding, horizontal laminations and ripplemark laminations are scarce in the sequence. Grains are well sorted, bigger fragments can be found only in lower parts of some beds. Bigger grains are exclusively fragments of crinoids. Typically rocks are composed of quartz grains and crinoid ossicles of 0.1-0.2 mm in diameter. The proportion of these components is close to equal. Quartz grains are well rounded, mostly monnocrystalline. Fragments of crinoids are broken, but marks of noticeable corrosion are lacking. Grains are cemented by blocky calcite, forming syntaxial overgrowth (sensu Bathurst 1975) on crinoids. Statistic comparison of diameter of quartz grains and fragments of crinoids revealed that crinoids are about 10% bigger in diameter. However statistic parameters of grain diameters calculated separately for quartz and crinoids are similar in individual samples, and fractionation of diameter for both grain types are close to normal. Differences of mean diameter of both grain types can be attributed to crinoid porosity (resultant lower density). Quartz grains and fragments of crinoids were brought together to sedimentation area by currents. The second ones did not experience long transport - porous fragments of crinoids are prone to destruction (abrasion). The large quantity of crinoids suggests that the area where they flourished was placed nearby.Areas of intensive crinoid growth can be often found on distinctive submarine slopes (Maliszewska 1998; Ostrowski 2003). Tectonically active Radom-Kraśnik Fault zone (Gutowski et al. 2003) could represent the area of development of crinoids in question.

Słowa kluczowe

EN

Callovian; synsedimentary tectonics; crinoids

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2006
• Tom: Vol. 4, no. 1
• Strony: 101--102
• Opis fizyczny: Bibliogr. 5 poz.

Twórcy

autor

Ostrowski S.

• University of Warsaw, Faculty of Geology, Al. Żwirki i Wigury 93, PL-02089 Warszawa, Poland,

Bibliografia

• Bathurst R. G. C. 1975. Carbonate sediments and their diagenesis. 1-658. Elsevier, New York.
• Gutowski J., Krzywiec P., Walaszczyk I. and Pożaryski W. 2003. Od ekstensji do inwersji - zapis aktywności północno-wschodniej brzeżnej strefy uskokowej Świętokrzyskiego segmentu bruzdy śródpolskiej w osadach jury górnej i kredy na podstawie interpretacji danych sejsmiki refleksyjnej. Tomy Jurajskie, 1: 124-125.
• Ostrowski S. 2003. Krawędzie bioherm mikrobialitowo-gąbkowych miejscem znacznego nagromadzenia płytek szkarłupni. Tomy Jurajskie, 1: 59-62.
• Samsonowicz J. 1932. Ogólna mapa geologiczna Polski w skali 1:100000, arkusz Opatów. Państwowy Instytut Geologiczny.
• Maliszewska A. 1998. Petrografia skał budujących skałkę w Leśnej koło Żywca. Biuletyn Państwowego Instytutu Geologicznego, 384: 37-52.