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Study presented here is performed on outcrops of fluvial deposits of the Nýrany Member in the easternmost part of the Kladno-Rakovník Basin (KRB), namely in Kralupy nad Vltavou area, close to the conventional boundary with the Mseno-Roudnice Basin (Holub 1997). The Nýrany Member deposits were studied at the Hostibejk Cliff and the Lobec Cliff, SSE-NNW oriented exposures in Kralupy nad Vltavou. Stratigraphically oldest strata are exposed along the southern margin of the Hostibejk Cliff whereas Stratigraphically youngest sediments crop out in the northern part of the Lobec Cliff. The cumulative thickness of the studied part of the stratigraphic succession exposed in the Hostibejk Cliff is estimated to be about 35 m and that one of the Lobec Cliff about 45m.
Six sedimentary facies were recognized: siltstone with plant material content (Fsm), fine-grained horizontally stratified sandstone (Sh), medium to coarse-grained cross stratified sandstone (Sc), fine to medium-grained massive conglomerate (Gm), matrix supported fine to medium-grained cross stratified conglomerate (Gcm) and clast supported coarse-grained cross stratified conglomerate (Gcc).
Architectural elements form the basis for the interpretation of depositional environment, they were defined by geometries and bounding surfaces using the methodology of Miall (1996). Individual elements represent different levels in terms of classification, e.g. sand and gravel bed forms are forming channels, channels are forming downstream accretion macroforms.
Five architectural elements were recognized:
1. Channels (CH), Abandoned channel fill consist of Sc, Gem and Gcc facies, with sharp erosive base cutting up to few metres into underlying deposits. CH often erode sand bed forms and other channels. Their geometry is of concave-up channel shape occasionally forming multi-storey channel geometry. CH thicknesses are up to 2 m in most cases and rarely up to 3.5 m. CH widths vary between 5 m and 25 m. The average width/thickness ratio is of 14.6 within the whole studied area, of 17.3 at southern margin of Hostibejk Cliff, of 13.3 at northern margin of Hostibejk Cliff and of 12.6 at Lobec Cliff. High lateral migration of channels is a typical feature. Most channels have multi-storey and multi-lateral nature. Decreasing width/thickness ratio from Hostibejk Cliff to the Lobec Cliff is the function of exposure orientation.
2. Sand bed forms (SB) consist of Sh and Sc facies, with sharp base. SB have sheet-like...