Lessy najstarsze i nowe stanowiska interglacjalnych gleb kopalnych na Działach Grabowieckich (Wyżyna Lubelska)
Abstract
Wykonane na na arkuszu Grabowiec Szczegółowej Mapy Geologicznej 1: 50 000 wiercenia w Bogucicach, Frankamionce, Czartorii, Horyszowie, Grabowcu, Wronowicach (Szymański, 1999) i badania geologiczne odsłonięcia w Szystowicach (Dolecki & Szymański, 1999, 2000; Dolecki & Wojtanowicz, 2000) wnoszą nowe dane do znajomości budowy geologicznej czwartorzędu Działów Grabowieckich. Z analizy profilów wynika, że na nierównej powierzchni skał kredowych leżą cienkie pokrywy iłów zwietrzelinowych skał kredowych z płatami residualnych piasków i żwirów eoplejstoceńskich, bądź silnie przemytych glin lodowcowych i piasków i żwirów wodnolodowcowych. W obrębie większych obniżeń podłoża kredowego zachowały się gliny zwałowe zlodowacenia san 1 rozdzielone osadami genezy peryglacjalnej ze śladami interstadialnej pedogenezy. Na stokach zachowały się osady czwartorzędowe starsze od zlodowacenia san 1; stanowią je podmorenowe mułki ilaste i piaszczyste lessopodobne. W profilu Bogucice K–6 na glinach zwałowych zlodowacenia san 1 zachowały się zróżnicowane facjalnie utwory lessopodobne z rozwiniętą na nich interglacjalną glebą mazowiecką. Wyżej, oddzielone rozległym hiatusem, leżą lessy i gleby kopalne interstadialne ze zlodowacenia liwca przykryte miąższymi lessami ze zlodowaceń odry, warty i wisły z glebami kopalnymi różnej rangi stratygraficznej. Powierzchnię bazalną teras vistuliańskich stanowią osady aluwialne warciańskie. Z rozmieszczenia hiatusów w profilach w układzie przestrzennym wynika, że w strefie granicznej Działów Grabowieckich i Kotliny Zamojskiej zachodziły w plejstocenie bardzo intensywne procesy erozji i denudacji.
THE OLDEST LOESSES AND NEW SITES OF INTERGLACIAL PALEOSOLS IN THE GRABOWIEC HEIGHT (LUBLIN UPLAND)
Summary
New data about geological structure of the Quaternary deposits in the Grabowiec Height have been provided by the borings made during geological mapping for the Detailed GeologicalMap 1 : 50 000, Grabowiec sheet. The boreholes made at Bogucice,
Frankamionka, Czartoria, Horyszów, Grabowiec, Wronowice (Szymański, 1999), and the exposure at Szystowice (Dolecki & Szymański, 1999, 2000; Dolecki & Wojtanowicz, 2000) are of special importance. An analysis of the sections shows that the uneven surface of the Cretaceous rocks is overlain by thin covers of residual clays, and patches of the Eopleistocene residual sands and gravels or strongly washed tills and fluvioglacial sands and gravels. Tills from the San 1 Glacial are preserved in larger depressions of the Cretaceous basement. Periglacial deposits with traces of interstadial pedogenesis occur within these tills. The oldest till was dated at 666 124 ka BP(Lub–3599) in the Bogucice section, and at 647 121 ka BP (Lub–3591) in the Honiatycze (4 bis) section. As it was found in the Honiatycze (K–4) boring on the higher terrace of the Sieniocha river, this till is overlain by the alluvial deposits occurring in the lower part of the Vistulian terrace. Older and younger loesses, separated by paleosols of different stratigraphic rank, and overlaying the Cretaceous weathered rocks, were found in the Czartoria (K–2) bormehole made on the flat interfluve area of the Grabowiec Height. On its slopes there are preserved the Quaternary deposits older than the San 1 Glacial, e.g. the undermoraine clayey and sandy loess-like silts found in the Honiatycze (4 bis) profile at Frankamionka. They correspond to the LN3b loess deposits in the stratigraphic scheme published by Dolecki (2001). Over the tills of the San 1 Glacial in the Bogucice (K–6) profile there are preserved the facially differentiated loess–like deposits topped with the paleosol from the Mazowian Interglacial. A great hiatus separates them from the overlying loesses and interstadial paleosols of the Liwiec Glacial, which are covered by thick loesses and paleosols of different stratigraphic rank from the Odranian, Wartanian and Vistulian Glacials. Spatial distribution of the hiatuses in the examined profiles provides stratigraphic evidence of very intensive erosion and denudation processes which took place during the Pleistocene in the boundary zone between the Grabowiec Height and Zamooeæ Basin.
THE OLDEST LOESSES AND NEW SITES OF INTERGLACIAL PALEOSOLS IN THE GRABOWIEC HEIGHT (LUBLIN UPLAND)
Summary
New data about geological structure of the Quaternary deposits in the Grabowiec Height have been provided by the borings made during geological mapping for the Detailed GeologicalMap 1 : 50 000, Grabowiec sheet. The boreholes made at Bogucice,
Frankamionka, Czartoria, Horyszów, Grabowiec, Wronowice (Szymański, 1999), and the exposure at Szystowice (Dolecki & Szymański, 1999, 2000; Dolecki & Wojtanowicz, 2000) are of special importance. An analysis of the sections shows that the uneven surface of the Cretaceous rocks is overlain by thin covers of residual clays, and patches of the Eopleistocene residual sands and gravels or strongly washed tills and fluvioglacial sands and gravels. Tills from the San 1 Glacial are preserved in larger depressions of the Cretaceous basement. Periglacial deposits with traces of interstadial pedogenesis occur within these tills. The oldest till was dated at 666 124 ka BP(Lub–3599) in the Bogucice section, and at 647 121 ka BP (Lub–3591) in the Honiatycze (4 bis) section. As it was found in the Honiatycze (K–4) boring on the higher terrace of the Sieniocha river, this till is overlain by the alluvial deposits occurring in the lower part of the Vistulian terrace. Older and younger loesses, separated by paleosols of different stratigraphic rank, and overlaying the Cretaceous weathered rocks, were found in the Czartoria (K–2) bormehole made on the flat interfluve area of the Grabowiec Height. On its slopes there are preserved the Quaternary deposits older than the San 1 Glacial, e.g. the undermoraine clayey and sandy loess-like silts found in the Honiatycze (4 bis) profile at Frankamionka. They correspond to the LN3b loess deposits in the stratigraphic scheme published by Dolecki (2001). Over the tills of the San 1 Glacial in the Bogucice (K–6) profile there are preserved the facially differentiated loess–like deposits topped with the paleosol from the Mazowian Interglacial. A great hiatus separates them from the overlying loesses and interstadial paleosols of the Liwiec Glacial, which are covered by thick loesses and paleosols of different stratigraphic rank from the Odranian, Wartanian and Vistulian Glacials. Spatial distribution of the hiatuses in the examined profiles provides stratigraphic evidence of very intensive erosion and denudation processes which took place during the Pleistocene in the boundary zone between the Grabowiec Height and Zamooeæ Basin.