Variscan fold system exposed in the Podhůra quarry (NE part of the Bohemian Massif, Block of Maleník)
Vol.23,No.1-2(2016)
In the Podhůra quarry situated in the SW part of the Block of Maleník southwards of Lipník nad Bečvou, the Culm sediments influenced by Variscan fold-thrust system are exposed. Geometry of the Variscan folds was studied in more detail at five sites (A to E), where hinge zones of these folds were well visible. The ESE-vergent system of asymmetric close folds of km order represents dominant tectonic structure observed in the Podhůra quarry. Synform of such fold of km order was studied at site A, antiform hinge zone was exposed at sites B and C. At the sites D and E, synform and antiform hinge zones of smaller open folds, of 100 meter order, were studied. Fold axes were predominantly NNE–SSW to NE–SW oriented, only at site E the N–S orientation of fold axis was found. These orientations are the same as predominant orientation of fold axes on the eastern margin of the Nízký Jeseník region. On the contrary, significant differences were found in the values of dip of axial planes and fold limbs. In the Podhůra quarry, the axial planes are subvertical or steeply WNW to NW dipping. In the case of fold of km order, one limb is subvertical, another limb is moderately WNW to NW dipping. It means that, compared to fold geometry on the eastern margin of the Nízký Jeseník region, the system of folds of km order studied in the SW part of the Block Maleník is westward to northwestward tilted steeper by at least 40°.
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