{"title":"PETROGRAFIE A MINERALOGIE KRUPNÍKOVÉHO TĚLESA NA LOKALITĚ ZADNÍ HUTISKO U VERNÍŘOVIC (HRUBÝ JESENÍK)","authors":"J. Zimák, Zuzana Juránková","doi":"10.5817/gvms2018-1-2-97","DOIUrl":"https://doi.org/10.5817/gvms2018-1-2-97","url":null,"abstract":"The paper deals with mineralogy and petrology of a soapstone body at the locality Zadní Hutisko near Vernířovice in the Hrubý Jeseník Mts. (NE part of the Bohemian Massif). The soapstone body is located in the northern spur of the Sobotín Massif composed dominately of amphibolites. The soapstone body shows a very distinct symmetrical internal zonation. Four main types of rocks can be distinguished in the direction from the centre to the edge of the body: i) soapstone (talc + dolomite); ii) talc schist; iii) tremolite schist; iv) chlorite schist. Common accessory minerals of the rocks are apatite and magnetite. Formation of the studied soapstone body may have been caused by metasomatic alteration of peridotite (serpentinite). Epidote-chlorite granofels with a variable content of amphibole (magnesiohornblende or tschermakite) and with a high content of opaque ore minerals (magnetite, hematite, and also ilmenite) was found at the contact of the soapstone body with amphibolite. Epidote-chlorite granofels has been formed by alteration of amphibolite.","PeriodicalId":37485,"journal":{"name":"Geological Research in Moravia and Silesia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71349340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Nehyba, Marika Dvořáková, Nela Doláková, Petr Dresler
{"title":"KVARTÉRNÍ SEDIMENTY NA SEVERNÍM PŘEDHRADÍ LOKALITY POHANSKO U BŘECLAVI","authors":"S. Nehyba, Marika Dvořáková, Nela Doláková, Petr Dresler","doi":"10.5817/GVMS2018-1-2-34","DOIUrl":"https://doi.org/10.5817/GVMS2018-1-2-34","url":null,"abstract":"Sedimentological study on the Northern bailey of the fortified site Pohansko allows identification of 9th lithofacies and 2 facies associations. The lower facies association is interpreted as an infill of fluvial channels (mostly mid-channel dunes) with two cycles of filling. The fluvial channels were relatively shallow and broad (high width/depth channel ratio) and they point to braided fluvial style and channel migration. The upper fluvial association reflects significant change of the fluvial style. The sedimentary infill of the upper fluvial association is interpreted as deposits of levee and overbank deposits. Results of the OSL dating for the sample of lower facies association provide an age of 13.5 ky. Such age can be correlated with the Upper Pleistocene Allerød Interstadial (13.7‒12.9 ky BP), i.e. relatively warmer phase of the Weichselian late glacial. Data of OSL dating for two samples from the upper facies association were 11.8 ky and 10.3 ky BP. The upper age can be correlated with Younger Dryas (12.9‒11.7 ky BP) whereas the lower one to Preboreal. The deposition of the upper facies associations are therefore interpreted as Uppermost Pleistocene to Early Holocene in age.","PeriodicalId":37485,"journal":{"name":"Geological Research in Moravia and Silesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47295417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Petrová, D. Buriánek, K. Kirchner, Oldřich Krejčí, František Laufek, S. Nehyba, J. Otava
{"title":"PESTRÉ SEDIMENTY OTTNANGU V BRNĚ-KOHOUTOVICÍCH","authors":"P. Petrová, D. Buriánek, K. Kirchner, Oldřich Krejčí, František Laufek, S. Nehyba, J. Otava","doi":"10.5817/GVMS2018-1-2-73","DOIUrl":"https://doi.org/10.5817/GVMS2018-1-2-73","url":null,"abstract":"The reddish coloured sediment layers (up to 5 m thick) were found within building pit in the Brno-Kohoutovice on the Libušina třída Avenue (NW part of Brno). These sediments were assigned to the Ottnangian based on characteristic pseudoassociation of microfossils. Smectite or illite/smectite dominates over kaolinite among the clay minerals. Minerals typomorphic for granitoids of the Brno Massif, i.e. epidote, amphibole and altered titanite, absolutely dominate (99 mod. %) within the assemblage of translucent heavy fraction. Minerals like garnet and staurolite which are typical for the Ottnangian sediments in this region, are presented only in accessoric amount. The chemical composition of the studied sediments is located between the chemical composition of granodiorites of the Brno Massif and Neogene clays. Relatively high content of Zr, Hf and HREE, which is interpreted as result of presence of very fine grained zircon in studied sediments, is characteristic. High content of SiO2 and comparatively low contents of Al2O3 and Fe2O3 indicates non-lateritic type of weathering. The chemical composition of studied sediments reflects semiarid to humid paleoclimate that the granitoids of the Brno Massif as parent rock have undergone.","PeriodicalId":37485,"journal":{"name":"Geological Research in Moravia and Silesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49215774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Petřík, Nela Doláková, S. Nehyba, Zuzana Lenďáková, Michaela Přišťáková, Katarína Adámeková, Libor Petr, Petr Dresler, Jiří Macháček
{"title":"ZANIKLÝ MEANDR U SEVERNÍHO PŘEDHRADÍ ARCHEOLOGICKÉ LOKALITY POHANSKO U BŘECLAVI","authors":"J. Petřík, Nela Doláková, S. Nehyba, Zuzana Lenďáková, Michaela Přišťáková, Katarína Adámeková, Libor Petr, Petr Dresler, Jiří Macháček","doi":"10.5817/gvms2018-1-2-41","DOIUrl":"https://doi.org/10.5817/gvms2018-1-2-41","url":null,"abstract":"The site is situated in the bottomland near the confluence of Dyje and Morava rivers. The junction area is split by many sides and inactive channels. The human impact (settlement establishment, deforestation and landscape management) is also reflected in the bottomland development. Processes lead to erosion, accumulation of sediments in river beds and changes in vegetation. One of the peaks of the settlement of the studied area can be considered during existence of the Great Moravian Empire when the settlement agglomerations developed directly in the floodplain. The area has been intensively archaeologically studied for a long time. In the context of the ongoing climate change and increasing intensity of floods the relationship between climate, natural conditions and the functioning of the human settlements comes to the forefront of scientific interest. For the reconstruction of the complicated floodplain development a combination of different research methods was used. For direct determination of stratigraphy an excavated transect through the sediments connecting the edge of the settlement (in the area of the so called Northern bailey) on the sand elevation („hrúd“) and lower flood-plain step in the area of presumptive paleomeander has been studied. Direct field documentation and palynological and sedimentological studies and 14C dating method were utilized. These methods have been supplemented by remote sensing methods: Geophysics (ERT, DEMP), Lidar. On their basis a digital relief model (extend of measured area was 54 000 m2) was created as well as a map of conductivity anomalies. The study documented a sequence of extinct riverbeds (a series of fluvial point bars) of various ages at the northern edge of Pohansko. Their stratigraphic position proves the stage when the active channel was eroding the edge of the archaeological site. The sediments stored in previous periods were destroyed by erosion in this space. The aggradation of the floodplain occurred in 14th–16th century. Results of pollen analysis indicate the presence of a mosaic of forested and open landscape of mesophilous alluvial woodlands and open areas. The immediate vicinity of the sedimentary area was not too much affected by agricultural activity at that time. Compared to palynospectra from sediments of the Great Moravian settlement, the deforestation intensity and the proportion of anthropogenic indicators were noticeably lower.","PeriodicalId":37485,"journal":{"name":"Geological Research in Moravia and Silesia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47155858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}