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Texlural ditersity of fluual iepow*

Abbrcviations - type of deposit: di - chanod deposit, ob - overbaok depoui d - duaad fili óepout, tf - dkmal ba iepou?. age designations PL1 - Oldcr PlenigiaaaL IPL - Intcrplcniglacul, PL2 - Youngrr Plemgbaal. LG - I PS-BO - Preborcal-Borcal. AT - Atlantic. SB-SA - Subborcal-Subatlantic. SA2 - Youngcr Subatłaadc Ic bet millenium) Sam ber mdicitet the total number of iamplcs.

yalley which extends in the subsiding mountain foreland represents an other type of sedimentation during which the vertical accretion of the vaUey floor was dominant (Niedziałkowska et al. 1985).

SELECTED EXAMPLES OF DIFFERENT TYPES OF FLUYIAL DEPOSITS

On the basis of the detailed analysis of sedimentary structures, of the macroscopic grain size determination in the deposits, of the spatial distribution of strata and of their location in the vertical profile different types of fluvial deposits have been determined. Additions are the results of grain size analysis and the location of samples on the CM Passega diagram.

Brzeźnica A — There occur typical sandy braided river deposits dating from the Younger Pleniglacial (Fig. 4). These are medium and fine sands including laminae of dusty sands, and even of clayey dusts (Fig. 5). Mz ranges from 1.3 to 3.2 0. Sorting improves upward from poor (<t, = 1.6) to well (a, = 0.4). The laminated dusty sands are characterized by Mz = 4.6-7.0 0. They are very poorly sorted (o, = 2.5). Stratification of the deposits is less well developed, only some strata show a horizontal lamination. Strata decrease upward in thickness (Fig. 5). Pro pert ies of the deposits indicate a channel environment with decreasing dynamics. Both individual strata and mean grain diameters become reduced upward (Fig. 5).

Brzeźnica B — Worthy of notę are channel deposits (a bar) which have been laid down by the meandering river in lateglacial times. These deposits are extensively exposed in a cross-section, some 200 m long (Fig. 4). The deposits show predominantly a tabular cross-bedding, locally alternating with a horizo-