Record details

    Vývoj sedimentace a fosilních společenstev ve spodním miocénu v jz. části karpatské předhlubně na Moravě
Statement of responsibility
    Slavomír Nehyba, Šárka Hladilová, Nela Doláková
Other titles
    Sedimentary evolution and changes of fossil assemblages in the sw.part of the Carpathian Foredeep in Moravia during the Lower Miocene
    Doláková, Nela
    Hladilová, Šárka, 1953-
    Nehyba, Slavomír
Source title - monograph
    Dynamika vztahů marinního a kontinentálního prostředí - Sborník příspěvků
    s. 47-58
    3 obr., 2 s.bibl.
    Anglické resumé
Subject group
    karpatská neogenní předhlubeň
    sedimentace deltová
    sedimentace fluviální
    sedimentace mořská
Geographical name
    Miroslav (Znojmo)
Abstract (in english)
   In the surroundings of Znojmo, where the Eggenburgian marine transgression penetrated first, the marine coast was formed by the deep-weathered crystalline rocks, predominantly with higly differentiated relief configurations (ridges, depressions). A more significant progradation of the sea basin occured in places with relatively slight coastal slopes (the Čejkovice region)im comparison with areas of relatively steeper slopes (the wider surroundings of Znojmo). During the Eggenburgin marine transgression, a complicated system of particular basins formed in this area. These basins had highly complicated shore-line contour and a variable mutual communication, as well as a communication with the open sea. Practically all characteristics of the marine environment with the exception of temperature (water depth and dynamics, light, aeration, salinity)were highly variable (there were oscillations)in all of these basins, indicating highly unstable sedimentary conditions in general.
   The sea was predominantly shallow (to about 40 m)and warm (temperatures corresponding to subtropics). The molluscan fauna responded to theses changes with a great variability in number of genera, species diversity and dominance, marine and slightly brachyhaline assemblages being substituted repeatedly by brachyhaline ones. In general, considerably extreme conditions in the marine environment are also manifested in the fact that only relatively poor molluscan asemblages occur in this area. Flora growing on the land also documented the relative proximity of the shoreline, therefore it was possible to study the very boundary between continental and marine environments. Due to the salinity oscillations as well as occasional higher evaporation influences, the coasts of individual sea gulfs and lagoons were repeatedly salted, enabling in places the growth of a relatively rich halophilous vegetation.
   The changes in the evaporation intensity and dilution of the seawater due to precipitation and fresh water inflows from the land were documented by the presence of fluctuations in the Chenopodiaceae and Ericaceae families. The growth of the salt meadows developed in time and space to the various growth stages of the coal swamp stations (the sea lagoons became gradually overgrown), and in places, even flora growing directly in the fresh water appears. Abrupt spatial and temporal changes of the palynospectra reflect a great variability of environmental conditions on the shore. Flora generally confirms a warm climate (the arctotertiary elements occurred only sporadically), and moreover abundant xenophilous elements, very similar to the recent mediterranean floras, occured in places. The marine transgression reached the surroundings of Miroslav later than the Znojmo area, because the progradation of the sea basin was generally accompanied with the shoreline transfer to the north.
   In the wider surroundings of Miroslav, the sea shore was flatter than in the Znojmo area, and als
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    7. 3. 2008
Import date
    8. 8. 2012