The impact of postglacial palaeoenvironmental changes on the properties of sediments in the kettle hole at the site of Jurki (NE Poland)

Abstract

This re search is fo cused on a small ket tle hole lo cated within the Mor¹g mo raines (I³awa Lake Dis trict, NE Po land). The study ob jec tive was to de ter mine the im pact of palaeoenvironmental changes on prop er ties of sed i ments fill ing the bot tom of the ket tle hole. Sedimentological, geo chem i cal, and palaeobotanical stud ies en abled us to dis tin guish sev eral de vel op ment phases of the ket tle hole, and clus ter anal y sis per formed on physicochemical data yielded seven lo cal geo chem i cal zones (Ju I/I to Ju I/VII ). The be gin ning of biogenic sed i men ta tion in the con di tions of a small wa ter body, func tion ing in the Late Gla cial pe riod (4.20-4.10 m), was de ter mined on the ba sis of palaeobotanical re search. Sed i ments de pos ited in the lake dur ing its fur ther evo lu tion were rich in microelements such as Ca, Na, Mg, and K, and to a smaller ex tent -Fe and Mn (Ju I/I-III lo cal geo chem i cal zones). The Late Gla cial lac us trine pe riod ended with the ac cu mu la tion of very silty, pol len-free gyttja, with a strati graphic hi a tus (Ju I/IV , 3.40-3.20 m). The sed i ments were en riched with SiO 2ter , which in di cates an in creased rate of slope ero sion, and con cre tions of Fe-Mn oc cur ring be low this layer (Ju III ) pro vide ev i dence for low er ing of the wa ter level and even des ic ca tion. In the Ho lo cene, the lac us trine pe riod ended with the ac cu mu la tion of coarse de tri tal gyttja (3.20-2.60 m). Palaeobotanical data in di cate that the next group of sed i ments were de pos ited in the Late Subboreal and Subatlantic pe ri ods (2.60-0.0 cm, Ju I/V-VII ; sedge peat). Their prop er ties were var ied and re lated to hydrologic con di tions, lim ited de nu da tion, and veg e ta tion suc ces sion. There was also a sig nif i cant change in the trophic con di tions of the wa ter and con se quently in the sed i ments of the ket tle hole, which changed dur ing the lac us trine pe riod from ba sic to acid, and strongly acid in the surface layer. This re ac tion may be re lated to a change in the wa ter re gime as well as to hu man im pact in the en vi ron ment, which led to the col o ni za tion of the peat bog by Sphag num moss.Key words: young gla cial land scape, ket tle hole, end mo raines, geo chem i cal anal y sis, biogenic de pos its.

Origin and post‐glacial evolution of surface cracks: A case study from the area of the Last Glaciation, north‐eastern Poland

“…On the other hand, the share of Al, Mg and K increases, and this may be an index of mechanical denudation (Figures 10 and 11), although it is not indicated by the Na:K ratio but rather by the erosion index (Borówka, 1992). Similar observations were described by Karasiewicz et al (2014, 2017) and Karasiewicz (2019). Low ratios Fe:Mn and Cu:Zn suggest oxidative conditions (Boyle, 2001; Wojciechowski, 2000).…”

“…During the Late Glacial and Holocene, they were transformed by periglacial, fluvial and aeolian processes and human activity (e.g. Karasiewicz, 2019;Karasiewicz et al, 2014Karasiewicz et al, , 2017.…”

The relationship between the chemical composition and lithology of Late Glacial and Holocene biogenic deposits of the Żabieniec mire (Central Poland)

“…Ad di tion ally, the role that sites of biogenic ac cu mu la tion play in the geo chem i cal cy cles of ma jor and trace el e ments is im por tant on a global scale. De pend ing on the hy dro log i cal condi tions of lakes and mires, cli mate change and hu man ac tiv ity, biogenic de pos its can be char ac ter ized by var i ous kinds of lithogeochemistry (Shotyk, 1996;Karasiewicz et al, 2017).…”

Lithology and geochemistry of the Late Glacial and Holocene sediments from Gostyń Lake (Western Pomerania, Myślibórz Lakeland)

“…The sites particularly useful for reconstructing climate changes and anthropogenic effects are sedimentation reservoirs subject to the evapotranspiration regime sensu Drwal (1973Drwal ( , 1974. Therefore, such sedimentation basins in recently glaciated areas have been targeted many times in studies aimed at assessing lacustrine responses to Late Glacial and Holocene changes in climate and human impact (Borówka 1990(Borówka , 1994Hulisz et al 2012;Karasiewicz et al 2014aKarasiewicz et al , 2017Mendyk et al 2016).…”