Record details

    Illite crystallinity and vitrinite reflectance in Paleozoic siliciclastics in the SE Bohemian Massif as evidence of thermal history
Statement of responsibility
    Eva Franců, Juraj Franců, Jiří Kalvoda
    Franců, Eva
    Franců, Juraj, 1957-
    Kalvoda, Jiří
Source title - serial
    Geologica carpathica
    Vol. 50, no. 5
    p. 365-372
    11 obr., 1 tab., 3 s.bibl.
    Zkr. název ser.: Geol. carpath.
Subject group
    břidlice jílová
    metamorfóza nízkostupňová
    minerály jílové
    moravskoslezské prevariské paleozoikum
    vrásnění variské
Geographical name
    Dambořice (Hodonín)
    Jedovnice (Blansko)
    Konice (Prostějov)
    Křtiny (Blansko)
    Mezihoří (Svitavy)
    Mokrá (Brno-venkov)
    Němčičky (Břeclav)
    Ochoz u Brna (Brno-venkov)
    Ostrov u Macochy (Blansko)
    Sloup (Blansko)
Abstract (in english)
   The termal maturity of Paleozoic rocks in the SE part of the Bohemian Massif is characterized by clay minerals and organic matter. The expandability of illite-smectite (S in I-S), illite crystallinity index (IC) and reflectance of (Rr) were measured and their regional distribution was evaluated. the mutual correlation of IC and Rr from diagenesis to very low-grade metamorphism is compared with the published data and used to distinguish data with more reliable paleogeothermal information from those affected by other factors. In the SE part the Paleozoic units have illite-smectites with an expanable component of 15-35 % S. The reflectance values (Rr of 0.55-1.1 %) are in good agreement with the expandability and suggest the oil window range of catagemesis with apleotemperature close to 100°C. In the NNW part of the area the clays contain no expandable layer in illite.
   The illite crystallinity (IC of 0.36-0.24 delta°2 ) and vitrinite reflectance (Rr from 3.17 to 5.23 %) indicate very low-grade metamorphic conditions with probable maximum paleotemperatures of 240-300°C. The systematic change in both clay and organic parameters show the gradual decrease in thermal exposure towards the front of the Variscan orogenic zone in the S and SE and suggest extensive erosion in the NNW
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    21. 3. 2008
Import date
    8. 8. 2012