3 research outputs found
Stratigraphy, facies and geodynamic settings of Jurassic formations in the Bükk Mountains, North Hungary: its relations with the other areas of the Neotethyan realm.
Jurassic mélange complexes related to the subduction of the Neotethys Ocean occur
in the Bükk Mountains, North Hungary. This paper characterizes the sedimentary sequence of
basin and slope facies that occur in the southwestern part of the Bükk Mountains, placing special
emphasis on the redeposited sedimentary rocks (olistostromes, olistoliths: Mónosbél Group) in order
to obtain information on the provenance of the clasts, and the mode and time of their redeposition.
The series of formations studied shows a general coarsening-upwards trend. Based on radiolarians
and foraminifera, the Mónosbél Group formed in Early to Late Bathonian time. The lower part
of the complex is typified by a predominance of pelagic carbonates, shale and radiolarite with
andesitic volcaniclastic intercalations. The higher part of the succession is characterized by polymictic
olistostromes. Large olistoliths that are predominantly blocks of Bathonian shallow marine limestone
(Bükkzsérc Limestone) appear in the upper part of the sequence. Based on the biostratigraphic and
sedimentological data, results of analyses of the redeposited clasts and taking into consideration
the concepts of the development of the western Neotethys domain, the evolutionary stages of the
sedimentary basins were defined. The onset of the compressional stage led to initiation of nappe
stacking that led to the formation of polymict olistostromes and then to the redeposition of large
blocks derived from out-of-sequence nappes of the former platform foreland