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The pa per pres ents the data on an Eemian-Late Gla cial sed i men tary se quence from the Zwierzyniec site, cen tral Po land. A num ber of bore holes doc u ment one or two or ganic lay ers that oc cur be neath one or two ho ri zons of clayey and silty de pos its of ice-dammed lakes. This study dem on strates to which ex tent the Zwierzyniec site can con trib ute to a better un der stand ing of the palaeoenvironmental changes dur ing the Eemian-Vistulian time-frame in cen tral Po land. To study it, a multi-proxy approach was ap plied, in volv ing: palynological and plant macrofossil anal y sis, study of round ing of quartz grains and mor phology of their sur face, and in ves ti ga tions of sand min er al ogy and till pe trog ra phy. The re sults show that a till bed is over lain by a sandy se ries cor re spond ing to the gla cial-inter gla cial tran si tion. Ei ther one or two dis tinct peaks of or ganic ac cu mu la tion are ev i denced by peat ho ri zons. The lower ho ri zon re cords spec tra with ha zel and horn beam, and did, there fore, ac cu mu late in the Eemian. Ob served only in some bore holes, the up per peat ho ri zon marks the BrÝrup (or the lower part of the Rederstall stadial) rep re sented by for est-steppe con di tions with patchy mo sa ics of larch and fur ther tran si tion into sedges and her baceous taxa. Lo cal ized in be tween the two peat se quences, the sandy ho ri zon marks a long-last ing ae olian trans for ma tion with weath er ing by frost in the Early Vistulian. Again, sig nif i cant changes of the palaeoenvironmental re gime oc curred, and are man i fested in the one or two ho ri zons of the glaciolacustrine sed i ments. This cor re sponded to the last gla ci ation in the region, when the ice-dammed lakes formed dur ing the Main Stadial.

This pa per pres ents the test re sults of hor i zon tal hy drau lic con duc tiv ity (k) of fen peats from east ern Po land. Three fen peatlands in the Lubartów Pla teau (3 ob jects marked as LP1, LP2 and LP3) and two in the Siedlce Pla teau (2 ob jects marked as SP1 and SP2) have been se lected. The ob jects rep re sent a val ley bog type and are sim i lar in peat thick ness, but dif fer ent in area size. They also vary in terms of bo tanic com po si tions and ba sic phys i cal and chem i cal pa ram e ters of peats. BAT permeameter was used for in situ mea sure ments of hor i zon tal hy drau lic con duc tiv ity. Hor i zon tal hy drau lic con duc tiv ity of the peats var ies from 1.3 ´ 10 -8 to 1.1 ´ 10 -6 m/s. The low est val ues of hor i zon tal hy drau lic con duc tiv ity were ob served for silted (high-ash) car bon ate peats and amor phous or pseudo-fi brous peats, while the high est val ues were ob served for unsilted (low-ash) non-car bon ate peats of fi brous struc ture. The anal y sis of vari abil ity of hor i zon tal hy drau lic con duc tiv ity showed that the low est val ues were ob served in each case for the bot tom of the stud ied pro file. The study al lowed to in di cate the specific ar eas within the peatlands dif fer ing in per me abil ity, and iden tify the role of in di vid ual ob jects as nat u ral geo log i cal bar riers.Key words: hy drau lic con duc tiv ity, nat u ral geo log i cal bar ri ers, peat, val ley bog.

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wrzykraj, P. 2016. Stress-strain behaviour analysis of Middle Polish glacial tills from Warsaw (Poland) based on the interpretation of advanced field and laboratory tests. Acta Geologica Polonica, 66 (3), 561-585. Warszawa.The selected parameters of the Wartanian and Odranian tills, with relation to their spatial occurrence, grain size distribution, mineralogical composition, matric suction and other physical characteristics, are presented. The assessment of the lithogenesis and stress history on the microstructure is attempted. The comparison of the compression and permeability characteristics from field and laboratory tests has been performed. Laboratory consolidation tests carried out with up to 20MPa vertical stress, revealed two yield stress values, one in the range of a couple hundreds kPa, the other in the range of a couple thousands kPa. Based on those results, the reliability of the soil preconsolidation assessment, with the use of the two different methods is discussed. The aspect of the triaxial strength reduction under the dynamic loading of diverse frequency and amplitude is raised. The research results depict a variety of possible geological-engineering characteristics, under the divergent constraints scenarios, of compression or strength weakening origin. The effects of the specialized research program will widen the possibilities of physio-mechanical and structural characterization of soils for geological-engineering purposes.