TEKTONIKA VÝSKYTU DEVONU U ADAMOVA

There is a special occurrence of Upper Devonian rocks within the Proterozoic granodiorites of the Brno Massif in the surroundings of Adamov (about 1 km NNE of Adamov). The outcrops consist of basal clastics and limestones. The rocks are strongly ductile or brittle-ductile strained. The dip direction and dip of foliation vary from 316/88 in the basal clastics to 256/50 in the limestones. The trend and plunge of axis of the cylindricity is 220/38 and corresponds to the average lineation 215/29. The setting of the Devonian rocks in Proterozoic granodiorites is interpreted as a tectonic slice along a fault plane. According to asymmetric structures, the western block was thrusted over the eastern block to the NE. The deformation passed through several steps: 1. Upper block was thrusted over the lower one (D1); 2. This tectonic zone was strained by younger dextral thrust (D2); 3. The final structure was modified by neotectonics faulting and rotation

Organic material within the modern fluvial deposits in the broader surroundings of Zlín

Content of organic material within the modern fluvial deposits were studied in the broader surroundings of Zlín. Detailed grain-size studies reveal that the organic material is relative mostly concentrated in the coarsest fraction of the studied samples. Distribution of the organic material can affected the content of organic pollutants within the studied samples.Content of organic material within the modern fluvial deposits were studied in the broader surroundings of Zlín. Detailed grain-size studies reveal that the organic material is relative mostly concentrated in the coarsest fraction of the studied samples. Distribution of the organic material can affected the content of organic pollutants within the studied samples

Revision of the geological documentation in the Křtiny Valley adits, Moravian Karst

Four adits excavated in the Křtiny Valley in the early fifties were documented and sampled especially from the viewpoint of structural geology and of genesis and origin of the sedimentary infi llings. The studied localities include limestones of the Macocha Formation (Givetian of the Býčí skála cycle), Devonian clastics and granitoids of the Brno Massif (Neoproterozoic). Relativelly monotonous fold structure of the limestones is disrupted by a thrust zone imbedding sandstone and granodiorite tectonic slices into the limestone sequence. NW–SE striking thrust zone bears N–S trending striae suggesting its strike-slip character. The shear sense was not yet determined. This thrust zone was rejuvenated and extremely altered during younger faulting, so nowadays it has a clayish appearance. Most of the psammites sampled in limestone cavitties display a typical „Ottnangian“ or „Cenomanian“ translucent heavy mineral assemblage (staurollite, kyanite, tourmaline, rutil) which proves redeposition (vertical transport) from Ottnangian and Cretaceous sands.Four adits excavated in the Křtiny Valley in the early fifties were documented and sampled especially from the viewpoint of structural geology and of genesis and origin of the sedimentary infi llings. The studied localities include limestones of the Macocha Formation (Givetian of the Býčí skála cycle), Devonian clastics and granitoids of the Brno Massif (Neoproterozoic). Relativelly monotonous fold structure of the limestones is disrupted by a thrust zone imbedding sandstone and granodiorite tectonic slices into the limestone sequence. NW–SE striking thrust zone bears N–S trending striae suggesting its strike-slip character. The shear sense was not yet determined. This thrust zone was rejuvenated and extremely altered during younger faulting, so nowadays it has a clayish appearance. Most of the psammites sampled in limestone cavitties display a typical „Ottnangian“ or „Cenomanian“ translucent heavy mineral assemblage (staurollite, kyanite, tourmaline, rutil) which proves redeposition (vertical transport) from Ottnangian and Cretaceous sands

Revision of the geological documentation in the Křtiny Valley adits, Moravian Karst

Four adits excavated in the Křtiny Valley in the early fifties were documented and sampled especially from the viewpoint of structural geology and of genesis and origin of the sedimentary infi llings. The studied localities include limestones of the Macocha Formation (Givetian of the Býčí skála cycle), Devonian clastics and granitoids of the Brno Massif (Neoproterozoic). Relativelly monotonous fold structure of the limestones is disrupted by a thrust zone imbedding sandstone and granodiorite tectonic slices into the limestone sequence. NW–SE striking thrust zone bears N–S trending striae suggesting its strike-slip character. The shear sense was not yet determined. This thrust zone was rejuvenated and extremely altered during younger faulting, so nowadays it has a clayish appearance. Most of the psammites sampled in limestone cavitties display a typical „Ottnangian“ or „Cenomanian“ translucent heavy mineral assemblage (staurollite, kyanite, tourmaline, rutil) which proves redeposition (vertical transport) from Ottnangian and Cretaceous sands.Four adits excavated in the Křtiny Valley in the early fifties were documented and sampled especially from the viewpoint of structural geology and of genesis and origin of the sedimentary infi llings. The studied localities include limestones of the Macocha Formation (Givetian of the Býčí skála cycle), Devonian clastics and granitoids of the Brno Massif (Neoproterozoic). Relativelly monotonous fold structure of the limestones is disrupted by a thrust zone imbedding sandstone and granodiorite tectonic slices into the limestone sequence. NW–SE striking thrust zone bears N–S trending striae suggesting its strike-slip character. The shear sense was not yet determined. This thrust zone was rejuvenated and extremely altered during younger faulting, so nowadays it has a clayish appearance. Most of the psammites sampled in limestone cavitties display a typical „Ottnangian“ or „Cenomanian“ translucent heavy mineral assemblage (staurollite, kyanite, tourmaline, rutil) which proves redeposition (vertical transport) from Ottnangian and Cretaceous sands

NAPJATOSTNÍ ANALÝZA DVOJČATNÝCH LAMEL V KALCITU S VYUŽITÍM OIM (EBSD)

In the second half of the 20th century a lot of paleostress estimation methods based on calcite twinning has been developed. Even though one can get required data on an Universal stage, Orientation Imaging Microscopy (OIM) using Electron Backscatter Diffraction (EBSD) provides much precise data. A new computer program has been developed for stress analysis of calcite twin lamellae, including most of the methods common in the literature, and processing Ustage and EBSD data as well. Combination of precise calcite lattice orientation measurements (EBSD) and numerical methods of paleostress analysis make calcite a very useful tool for evaluating deformation pathways in sedimentary complexes

3D STAVBA LOMŮ MOKRÁ (PŘEDBĚŽNÉ VÝSLEDKY)

The limestones in Mokrá quarries (Moravian Karst) underwent complex folding and thrusting during the Variscan orogeny. Two systems of folds were recognised: the older one is oriented NNWSSE and refolded by a younger system of ENE–WSW direction. A precise stratigraphic research in combination with structural data made possible to interpret the 3D tectonics of the area as a large anticline plunging to the SE with the angle of 20°. The lower overturned branch of this anticline was ruptured and duplicated during thrusting in the end of folding. This structure was affected by several phases of brittle fracturing