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EN
This article presents the results of an integrated interpretation of measurements made using Audio-Magnetotellurics and Seismic Refection geophysical methods. The obtained results were used to build an integrated geophysical model of shal low subsurface cover consisting of Cenozoic deposits, which then formed the basis for a detailed lithological and tectonic interpretation of deeper Mesozoic sediments. Such shallow covers, consisting mainly of glacial Pleistocene deposits, are typical for central and northern Poland. This investigation concentrated on delineating the accurate geometry of Obrzycko Cenozoic graben structure flled with loose deposits, as it was of great importance to the acquisition, processing and interpretation of seismic data that was to reveal the tectonic structure of the Cretaceous and Jurassic sediments which underly the study area. Previously, some problems with estimation of seismic static corrections over similar grabens flled with more recent, low-velocity deposits were encountered. Therefore, a novel approach to estimating the exact thickness of such shallow cover consisting of low-velocity deposits was applied in the presented investigation. The study shows that some alternative geophysical data sets (such as magnetotellurics) can be used to signifcantly improve the imaging of geological structure in areas where seismic data are very distorted or too noisy to be used alone
EN
The paper is focused on the palaeographic development of the western part of the Holy Cross Mountains, Poland, during the maximum extent of the Sanian 2 (MIS 12) ice sheet and its retreat. The studies were based on archival cartographic data, coupled with new lithological and petrographic analyses of limni- and fluvioglacial sands, i.e., grain-size composition, quartz grain morphology and heavy mineral analysis, as well as analysis of the erratic material of tills. The results confirm the regional variability of the erratic material in the Sanian 2 tills and point to the long-term development of fluvioglacial sands cover documenting cold climate conditions. They also evidence that the western part of the Holy Cross Mountains was the area where two oppositely directed ice sheet lobes (Radoszyce and Sandomierz) advanced during the Sanian 2 Glaciation and that deglaciation of the area took place in two stages. Huge quantities of meltwater released at that time contributed to the intensification of earlier initiated karst phenomena, as well as filling of the existing caves by fluvioglacial sands.
PL
Wychodnie skalne środkowego Bałtyku, wysp szwedzkich oraz południowo-wschodniej Szwecji były obszarem dominującej egzaracji tej części lądolodu, która podczas fazy pomorskiej późnego plenivistulianu dotarła po NW Polskę i NE Niemcy. W zespole wszystkich skandynawskich narzutniaków najmłodszych osadów depozycji glacjalnej z NW Polski i NE Niemiec około 30-40% stanowią skały krystaliczne. Ich obszarem macierzystym jest tarcza bałtycka, uformowana w proterozoiku. Do najważniejszych narzutniaków pochodzących z tarczy bałtyckiej należą: granity Uppsala i Stockholm, granit rapakivi Aland, eratyki z Dalarny (granity Garberg, Jima, Siljan oraz porfir Dalama). Są to także eratyki egzarowane w transskandynawskim paśmie magmowym: granity Smáland, Vánevik, Vörlebo, Filipstad, Kristinehamn, czerwone i szare granity Vöxjö, porfiry Páscallavik; dalej są to eratyki z regionu Blekinge-Bornholn (granity Karlshamn, Spinkamála, Halen, Vánga, Hammer, Vang, Svaneke) oraz eratyki z regionu gnejsowego SW Szwecji (sjenity Glimákra i Vaggeryd, gnejs Járna i czarnokit Varberg). W grupie skał narzutowych są także skały uformowane podczas młodszych zdarzeń geologicznych (np. permski porfir rombowy z Oslo czy jurajski bazalt ze Skanii). Skały macierzyste są zlokalizowane również w obrębie pokrywy osadowej dna Bałtyku centralnego i południowego, której powstanie wiąże się ze zdarzeniami geologicznymi w neoproterozoiku, wczesnym paleozoiku i kredzie. Z dna Bałtyku, wysp Gotlandii i Olandii oraz państw nadbałtyckich pochodzi około 60-70% wszystkich eratyków osadowych późnoplenivistuliańskiej depozycji glacjalnej. Są to: piaskowce jotnickie, wapienie ordowiku i syluru, dewońskie piaskowce i dolomity. Z południowo-zachodniego Bałtyku pochodzą górnokredowe wapienie oraz górnokredowe i paleogeńskie krzemienie.
EN
The hardrock substratum of the middle Baltic Sea, Swedish islands and south-eastern Sweden are the main areas eroded by the late Pleniweichselian ice sheet. The erratics that the ice transported away from these areas are now found in the youngest glacial deposits of NW Poland and NE Germany. The Scandinavian erratics sampled from the youngest glacial deposits in NW Poland and NE Germany consist for 30-40% of crystalline rocks derived from the Proterozoic of the Fennoscandian (Baltic) Shield. They include Svecofennian rocks (Uppsala granite, Stockholm granite, Áland rapakivi granite), granites and porphyries from Dalama (Garberg granite, Jima granite, Siljan granite, Dalama porhyry), as well as materiał from the Transscandinavian Igneous Belt (Smáland granite, Vánevik granite, Vörlebo granite, red and grey Vöxjö granites, Páscallavik porphyry, Filipstad granite and Kristinehamn granite), from the Blekinge-Bornholn region (Karlshamn granite, Spinkamála granite, Halen granite, Vánga granite, Hammer granite, Vang granite, Svaneke granite), and the gneissic region of SW Sweden (Glimákra syenite, Vaggeryd syenite, Járna gneiss, Varberg chamockit). Other erratics come from younger volcanic rocks, dating back to the Late Palaeozoic and Jurassic/Cretaceous (e.g., the romb porphyry from the Oslo graben and Scanian basalt). The sedimentary cover of the Neoproterozoic, the Lower Palaeozoic and the Cretaceous (from the Baltic Sea, Aland Islands, Gotland, Öland and the Baltic states) are also source rocks. Glacial sediments deposited directly south of the Baltic Sea consist for 60-70% of Fennoscandian sedimentary erratics. They include: Jotnian sandstones, Ordovician and Silurian limestones, Devonian sandstones (Old Red) and dolomites. Other source areas of indicator erratics are located along the Sorgenfrei-Teisseyre-Tornquist zone and further to the south-west (e.g. Late Cretaceous limestones, Late Cretaceous and Paleogene flints).
EN
There are erratic boulders drifted with the last continental ice sheet in the glacial deposits of the Polish Lowland. Their outcrops are situated in the Baltic Shield area as well as to the south of it, in the central and southern Baltic Sea bottom. Indicator erratics, statistical erratics and the others are distinguished in coarse-gravels association. The research into the identification of the indicator erratics are designed for the specification of the Scandinavian and Baltic alimentation centres of different age glacial tills and their fluvioglacial counterparts; they are also aimed at determining the direction of the distant transport as well as the ice-sheet and its streams transgression route to the deposition places. Effectiveness of the analysis depends to a large extent on the erratic correct classification and this ability happens in turn to be burdened with a subjective evaluation of the clearly visible features of an erratic. In the text attention will be paid to the advantages and disadvantages of the analysis on the indicator boulders of the glacial deposits.
EN
The sediment texture data (grain size, quartz grain abrasion, and roundness) from a range of different glacial environments at Hansbreen in southern Spitsbergen are presented. The six main sediment groups were distinguished: subglacial till, supraglacial debris cover, debris flow deposits, supra- and englacial meltwater stream deposits, dirt cone and proglacial glaciofluvial deposits. The division is supported by grain size statistics (presented in form of 3D diagrams), and is also legible in quartz grain abrasion differences. The latter one reveals strong changeability depending on the grain size class. No correlation between clay ratio and standard deviation vs. quartz grain abrasion was found. Lithology has limited impact on clast roundness (analysed for > 2.8 mm fraction), although restricted by short distance and time of transportation. A comparison with similar data set from Werenskioldbreen shows the deposits of Hansbreen as more mature, which is probably caused by reworking of older deposits and longer transport.
PL
Wybrane cechy teksturalne osadów (rozkład uziarnienia, abrazja ziarna kwarcowego - grainformametria mechaniczna i obtoczenie) zostały określone dla prób z różnych środowisk glacjalnych lodowca Hansa (Hansbreen), południowy Spitsbergen. Wyróżniono 6 podstawowych grup osadów: osady subglacjalane, pokryw supraglacjalnych, osady spływów błotnych, stożków ablacyjnych, supra- i inglacjalnych potoków wód roztopowych oraz proglacjalnych osadów fluwioglacjalnych. Podział ten znalazł swoje odzwierciedlenie w analizie statystycznych wskaźników uziarnienia (prezentowanych w postaci diagramów 3D) i jest również czytelny w zróżnicowaniu abrazji ziarna kwarcowego. Ta ostatnia wykazuje zróżnicowanie w zależności od wielkości frakcji. Nie wykryto wyraźnej relacji pomiędzy wskaźnikiem ilastości oraz odchyleniem standardowym a wskaźnikami obtoczenia. Litologia ma ograniczony wpływ na obtoczenie (analizowana frakcja > 2,8 mm). Porównanie z podobnym zestawem danych dla lodowca Werenskiolda (Werenskioldbreen) wskazuje na większą dojrzałość osadów lodowca Hansa, prawdopodobnie można to wiązać z redepozycją starszych osadów i dłuższym transportem.
EN
This paper presents a reconstruction of the pre-Elsterian fluvial pattern in the Western Sudetes Mts using borehole and geophysical data. These valleys were blocked by the advancing Elsterian ice sheet, enabling the proglacial lakes to be formed, and most of them were later covered by the ice sheet which entered into the mountain interior. The valleys are now filled with 5-15 m of 'pre-glacial' fluvial gravels and a generally thick glacial series. The latter comprises a till and glaciofluvial and glaciolacustrine sediments, including varved clay. The former valleys occur along the axes of the present-day valleys or at their margins, or occur in watershed areas which have been recently abandoned. Post-Elsterian changes in valley pattern is due to the filling of old valleys and epigenetic incision of new valleys along the tributary valleys. The valley fragments which preserved their former position were deeply incised, with the almost complete removal of older deposits. Some fault activity has been documented for that time in the marginal zone of the Sudetes Mts. The Saalian ice sheet only entered the marginal part of the Sudetes Mts, and hydrographic changes from that time are smaller.
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