Saalian

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 1809 Experts worldwide ranked by ideXlab platform

Florence Colleoni - One of the best experts on this subject based on the ideXlab platform.

  • The sensitivity of the Late Saalian (140 ka) and LGM (21 ka) Eurasian ice sheets to sea surface conditions
    Climate Dynamics, 2010
    Co-Authors: Florence Colleoni, Johan Liakka, Gehrard Krinner, Martin Jakobsson, Simona Masina, V. Peyraud
    Abstract:

    This work focuses on the Late Saalian (140 ka) Eurasian ice sheets' surface mass balance (SMB) sensitivity to changes in sea surface temperatures (SST). An Atmospheric General Circulation Model (AGCM), forced with two preexisting Last Glacial Maximum (LGM, 21 ka) SST reconstructions, is used to compute climate at 140 and 21 ka (reference glaciation). Contrary to the LGM, the ablation almost stopped at 140 ka due to the climatic cooling effect from the large ice sheet topography. Late Saalian SST are simulated using an AGCM coupled with a mixed layer ocean. Compared to the LGM, these 140 ka SST show an inter-hemispheric asymmetry caused by the larger ice-albedo feedback, cooling climate. The resulting Late Saalian ice sheet SMB is smaller due to the extensive simulated sea ice reducing the precipitation. In conclusion, SST are important for the stability and growth of the Late Saalian Eurasian ice sheet.

  • On the Late Saalian glaciation (160 - 140 ka): a climate modeling study
    2009
    Co-Authors: Florence Colleoni
    Abstract:

    This thesis focuses on the glaciation of the Late Saalian period (160 -140 ka) over Eurasia. The Quaternary Environment of the Eurasian North project evidenced that during this period, the Eurasian ice sheet was substantially larger than during the entire Weichselian cycle and especially than during the Last Glacial Maximum (21 ka, LGM). The Late Saalian astronomical forcing were different than during the LGM while greenhouse gas concentrations were similar. To understand how this ice sheet could have grown so large over Eurasia during the Late Saalian, we use an Atmospherical General Circulation Model (AGCM), an AGCM coupled to an oceanic mixed layer and a vegetation model to explore the influence of regional parameters, sea surface temperatures (SST) and orbital parameters on the surface mass balance (SMB) of the Late Saalian Eurasian ice sheet. At 140 ka, proglacial lakes, vegetation and simulated Late Saalian SST cool the Eurasian climate, reducing the ablation along the southen margins. Dust deposition on snow have the opposite effect. The presence of a Canada Basin ice-shelf during MIS 6 in the Arctic Ocean, does not affect the mass balance of the ice sheet. According to geological evidences, the Late Saalian Eurasian ice sheet reached its maximum extent before 160 ka. Northern Hemisphere high latitudes summer insolation shows a large insolation peak towards 150 ka. The simulated climate prior to 140 ka is milder and ablation is larger along the southern margins of the Eurasian ice sheet although the mean annual SMB is positive. The Late Saalian Eurasian ice sheet, may have been large enough to generate its own cooling needed for its maintenance over Eurasia.

  • influence of regional parameters on the surface mass balance of the eurasian ice sheet during the peak Saalian 140 kya
    Global and Planetary Change, 2009
    Co-Authors: Florence Colleoni, Martin Jakobsson, Vincent Peyaud, Gerhard Krinner, Catherine Ritz
    Abstract:

    Recent geologically-based reconstructions of the Eurasian ice sheet show that during the peak Saalian (≈ 140 kya) the ice sheet was larger over Eurasia than during the Last Glacial Maximum (LGM) at ...

  • Sensitivity of the Late Saalian (140 kyrs BP) and LGM (21 kyrs BP) Eurasian ice sheet surface mass balance to vegetation feedbacks
    Geophysical Research Letters, 2009
    Co-Authors: Florence Colleoni, Gerhard Kirnner, Martin Jakobsson
    Abstract:

    This work uses an atmospheric general circulation model (AGCM) asynchronously coupled to an equilibrium vegetation model to investigate whether vegetation feedbacks could be one of the reasons why the Late Saalian ice sheet (140 kyrs BP) in Eurasia was substantially larger than the Last Glacial Maximum (LGM, 21 kyrs BP) Eurasian ice sheet. The modeled vegetation changes induce a regional cooling for the Late Saalian while they cause a slight regional warming for LGM. As a result, ablation along the margins of the Late Saalian ice sheet is significantly reduced, leading to an increased surface mass balance, while there are no significant mass balance changes observed from vegetation feedbacks at LGM.

  • the late Saalian surface ocean 140 ka sensitivity of the late Saalian eurasian ice sheet to sea surface conditions
    2009
    Co-Authors: Florence Colleoni, Johan Liakka, Gehrard Krinner, Martin Jakobsson, Simona Masina, Vincent Peyaud
    Abstract:

    This work focuses on the Late Saalian (140 ka) and LGM (21 ka) Eurasian ice sheets surface mass balance (SMB) sensitivity to changes in sea surface temperatures (SST). Since no global Late Saalian ...

Martin Jakobsson - One of the best experts on this subject based on the ideXlab platform.

Tobias Lauer - One of the best experts on this subject based on the ideXlab platform.

  • the middle pleistocene fluvial sequence at uichteritz central germany chronological framework paleoenvironmental history and early human presence during mis 11
    Geomorphology, 2020
    Co-Authors: Tobias Lauer, Marcel Weiss, Wolfgang Bernhardt, Susann Heinrich, Ivo Rappsilber, Mareike Cordula Stahlschmidt, Hans Von Suchodoletz, Stefan Wansa
    Abstract:

    Abstract The site of Uichteritz (Saxony-Anhalt, Germany) is a Quaternary gravel quarry hosting several Middle-Pleistocene fluvial units of the Saale River. This fluvial archive contains detailed information on (1) the timing of Middle Pleistocene fluvial aggradation and erosion periods in the region, (2) the driving forces for those alternations, as well as (3) early human presence indicated by the presence of Lower Paleolithic stone artefacts. Here we establish a luminescence-based numerical chronology at Uichteritz. Additionally, geophysical, sedimentological and micromorphological analyses were applied to obtain information on depositional and post-depositional processes of the fluvial sequence. Our results point to several fluvial aggradation periods between ca. 420 and 180 ka. A first fluvial unit was deposited during the late Elsterian period, followed by formation of a Luvisol during MIS 11 and its fluvial reworking at the transition from MIS 11 to MIS 10 and/or during early MIS 10. These MIS 10/11 deposits, with an age of about 400 ka, also contain reworked Lower Paleolithic stone artefacts that document the initial appearance of humans in northwestern central Europe during MIS 11. After a period of fluvial incision during MIS 10, which was accompanied by a change in the course of the Saale River, several stacked fluvial sequences of the Saalian Main Terrace (SMT) formed between MIS 8 and MIS 6, mainly during cold climatic periods. Our age estimates confirm the correlation of the Elsterian ice advances with MIS 12, and the Saalian ice advances with later MIS 6.

  • Timing of the Saalian- and Elsterian glacial cycles and the implications for Middle – Pleistocene hominin presence in central Europe
    Scientific Reports, 2018
    Co-Authors: Tobias Lauer, Marcel Weiss
    Abstract:

    By establishing a luminescence-based chronology for fluvial deposits preserved between the Elsterian- and Saalian tills in central Germany, we obtained information on the timing of both the Middle Pleistocene glacial cycles and early human appearance in central Europe. The luminescence ages illustrate different climatic driven fluvial aggradation periods during the Saalian glacial cycle spanning from 400–150 ka. The ages of sediments directly overlying the Elsterian till are approximately 400 ka and prove that the first extensive Fennoscandian ice sheet extension during the Quaternary correlates with MIS 12 and not with MIS 10. Furthermore, the 400 ka old fluvial units contain Lower Paleolithic stone artefacts that document the first human appearance in the region. In addition, we demonstrate that early MIS 8 is a potential date for the onset of the Middle Paleolithic in central Germany, as Middle Paleolithic stone artefacts are correlated with fluvial units deposited between 300 ka and 200 ka. However, the bulk of Middle Paleolithic sites date to MIS 7 in the region. The fluvial units preserved directly under the till of the southernmost Saalian ice yield an age of about 150 ka, and enable a correlation of the Drenthe stage to late MIS 6.

  • timing of the Saalian and elsterian glacial cycles and the implications for middle pleistocene hominin presence in central europe
    Scientific Reports, 2018
    Co-Authors: Tobias Lauer, Marcel Weiss
    Abstract:

    By establishing a luminescence-based chronology for fluvial deposits preserved between the Elsterian- and Saalian tills in central Germany, we obtained information on the timing of both the Middle Pleistocene glacial cycles and early human appearance in central Europe. The luminescence ages illustrate different climatic driven fluvial aggradation periods during the Saalian glacial cycle spanning from 400-150 ka. The ages of sediments directly overlying the Elsterian till are approximately 400 ka and prove that the first extensive Fennoscandian ice sheet extension during the Quaternary correlates with MIS 12 and not with MIS 10. Furthermore, the 400 ka old fluvial units contain Lower Paleolithic stone artefacts that document the first human appearance in the region. In addition, we demonstrate that early MIS 8 is a potential date for the onset of the Middle Paleolithic in central Germany, as Middle Paleolithic stone artefacts are correlated with fluvial units deposited between 300 ka and 200 ka. However, the bulk of Middle Paleolithic sites date to MIS 7 in the region. The fluvial units preserved directly under the till of the southernmost Saalian ice yield an age of about 150 ka, and enable a correlation of the Drenthe stage to late MIS 6.

  • new age constraints for the Saalian glaciation in northern central europe implications for the extent of ice sheets and related proglacial lake systems
    Quaternary Science Reviews, 2018
    Co-Authors: Jorg Lang, Tobias Lauer, Jutta Winsemann
    Abstract:

    Abstract A comprehensive palaeogeographic reconstruction of ice sheets and related proglacial lake systems for the older Saalian glaciation in northern central Europe is presented, which is based on the integration of palaeo-ice flow data, till provenance, facies analysis, geomorphology and new luminescence ages of ice-marginal deposits. Three major ice advances with different ice-advance directions and source areas are indicated by palaeo-ice flow directions and till provenance. The first ice advance was characterised by a southwards directed ice flow and a dominance of clasts derived from southern Sweden. The second ice advance was initially characterised by an ice flow towards the southwest. Clasts are mainly derived from southern and central Sweden. The latest stage in the study area (third ice advance) was characterised by ice streaming (Hondsrug ice stream) in the west and a re-advance in the east. Clasts of this stage are mainly derived from eastern Fennoscandia. Numerical ages for the first ice advance are sparse, but may indicate a correlation with MIS 8 or early MIS 6. New pIRIR290 luminescence ages of ice-marginal deposits attributed to the second ice advance range from 175 ± 10 to 156 ± 24 ka and correlate with MIS 6. The ice sheets repeatedly blocked the main river-drainage pathways and led to the formation of extensive ice-dammed lakes. The formation of proglacial lakes was mainly controlled by ice-damming of river valleys and major bedrock spillways; therefore the lake levels and extends were very similar throughout the repeated ice advances. During deglaciation the lakes commonly increased in size and eventually drained successively towards the west and northwest into the Lower Rhine Embayment and the North Sea. Catastrophic lake-drainage events occurred when large overspill channels were suddenly opened. Ice-streaming at the end of the older Saalian glaciation was probably triggered by major lake-drainage events.

Marcel Weiss - One of the best experts on this subject based on the ideXlab platform.

  • the middle pleistocene fluvial sequence at uichteritz central germany chronological framework paleoenvironmental history and early human presence during mis 11
    Geomorphology, 2020
    Co-Authors: Tobias Lauer, Marcel Weiss, Wolfgang Bernhardt, Susann Heinrich, Ivo Rappsilber, Mareike Cordula Stahlschmidt, Hans Von Suchodoletz, Stefan Wansa
    Abstract:

    Abstract The site of Uichteritz (Saxony-Anhalt, Germany) is a Quaternary gravel quarry hosting several Middle-Pleistocene fluvial units of the Saale River. This fluvial archive contains detailed information on (1) the timing of Middle Pleistocene fluvial aggradation and erosion periods in the region, (2) the driving forces for those alternations, as well as (3) early human presence indicated by the presence of Lower Paleolithic stone artefacts. Here we establish a luminescence-based numerical chronology at Uichteritz. Additionally, geophysical, sedimentological and micromorphological analyses were applied to obtain information on depositional and post-depositional processes of the fluvial sequence. Our results point to several fluvial aggradation periods between ca. 420 and 180 ka. A first fluvial unit was deposited during the late Elsterian period, followed by formation of a Luvisol during MIS 11 and its fluvial reworking at the transition from MIS 11 to MIS 10 and/or during early MIS 10. These MIS 10/11 deposits, with an age of about 400 ka, also contain reworked Lower Paleolithic stone artefacts that document the initial appearance of humans in northwestern central Europe during MIS 11. After a period of fluvial incision during MIS 10, which was accompanied by a change in the course of the Saale River, several stacked fluvial sequences of the Saalian Main Terrace (SMT) formed between MIS 8 and MIS 6, mainly during cold climatic periods. Our age estimates confirm the correlation of the Elsterian ice advances with MIS 12, and the Saalian ice advances with later MIS 6.

  • timing of the Saalian and elsterian glacial cycles and the implications for middle pleistocene hominin presence in central europe
    Scientific Reports, 2018
    Co-Authors: Tobias Lauer, Marcel Weiss
    Abstract:

    By establishing a luminescence-based chronology for fluvial deposits preserved between the Elsterian- and Saalian tills in central Germany, we obtained information on the timing of both the Middle Pleistocene glacial cycles and early human appearance in central Europe. The luminescence ages illustrate different climatic driven fluvial aggradation periods during the Saalian glacial cycle spanning from 400-150 ka. The ages of sediments directly overlying the Elsterian till are approximately 400 ka and prove that the first extensive Fennoscandian ice sheet extension during the Quaternary correlates with MIS 12 and not with MIS 10. Furthermore, the 400 ka old fluvial units contain Lower Paleolithic stone artefacts that document the first human appearance in the region. In addition, we demonstrate that early MIS 8 is a potential date for the onset of the Middle Paleolithic in central Germany, as Middle Paleolithic stone artefacts are correlated with fluvial units deposited between 300 ka and 200 ka. However, the bulk of Middle Paleolithic sites date to MIS 7 in the region. The fluvial units preserved directly under the till of the southernmost Saalian ice yield an age of about 150 ka, and enable a correlation of the Drenthe stage to late MIS 6.

  • Timing of the Saalian- and Elsterian glacial cycles and the implications for Middle – Pleistocene hominin presence in central Europe
    Scientific Reports, 2018
    Co-Authors: Tobias Lauer, Marcel Weiss
    Abstract:

    By establishing a luminescence-based chronology for fluvial deposits preserved between the Elsterian- and Saalian tills in central Germany, we obtained information on the timing of both the Middle Pleistocene glacial cycles and early human appearance in central Europe. The luminescence ages illustrate different climatic driven fluvial aggradation periods during the Saalian glacial cycle spanning from 400–150 ka. The ages of sediments directly overlying the Elsterian till are approximately 400 ka and prove that the first extensive Fennoscandian ice sheet extension during the Quaternary correlates with MIS 12 and not with MIS 10. Furthermore, the 400 ka old fluvial units contain Lower Paleolithic stone artefacts that document the first human appearance in the region. In addition, we demonstrate that early MIS 8 is a potential date for the onset of the Middle Paleolithic in central Germany, as Middle Paleolithic stone artefacts are correlated with fluvial units deposited between 300 ka and 200 ka. However, the bulk of Middle Paleolithic sites date to MIS 7 in the region. The fluvial units preserved directly under the till of the southernmost Saalian ice yield an age of about 150 ka, and enable a correlation of the Drenthe stage to late MIS 6.

Dariusz Krzyszkowski - One of the best experts on this subject based on the ideXlab platform.

  • short term changes in a Saalian glacial lake the parchliny c site central poland
    Catena, 2017
    Co-Authors: Lucyna Wacheckakotkowska, Dariusz Krzyszkowski, Jarmila Krzyminska, Wojciech Drzewicki, Mariusz Orion Jedrysek
    Abstract:

    Abstract The paper discusses results of sedimentological, faunal (molluscs, ostracods) and geochemical studies of an 80-cm-thick rhythmite succession within a glaciolacustrine sequence (8–10 m in thickness) of the Ławki Formation exposed at the Parchliny C site, in the tectonically active Kleszczow Graben, central Poland. Sedimentological studies show the predominance of rhythmically deposited pale grey muds (2.0–7 cm thick) and black clays (0.5–5 cm thick). The pro-glacial sediments have yielded the first examples of Saalian molluscan and ostracod communities to be recorded from Europe and probably globally. The presence of a lake basin is confirmed by the freshwater species fauna: Candona neglecta, Cypridopsis vidua, Fabaeformiscandona protzi, Limnocythere inopinata, Limnocytherina sanctiparicii Cyclocypris laevis, Metacypris cordata (ostracods) and Anodonta cygnaea, Ancylus fluviatilis, Theodoxus fluviatilis, Bithynia tentaculata, Valvata piscinalis and Pisidium sp. (molluscs), suggestive of deposition during a period of colder climatic conditions, although some species might be indicative of a warmer period, resembling an interglacial. The whole section has a high carbonate content, up to several tens percent. The carbonates are enriched in the heavy isotope of oxygen. The isotopic composition of carbon and oxygen indicates two stages of lake development. The transition of the lake from a hydrologically open to a closed system with significant evaporation has been reconstructed from correlation of δ13C and δ18O. Sedimentological, faunal (molluscs, ostracods) and stable-isotope studies of the Saalian Ławki Formation have revealed an important snapshot – a 14-year record in the hydrological transformation of this specific pro-glacial lake system.

  • Saalian sediments of the belchatow outcrop central poland
    Boreas, 2008
    Co-Authors: Dariusz Krzyszkowski
    Abstract:

    The deposits of six glacial episodes, including five till beds and fluvial deposits of one temperate substage, stratigraphically lying between the Holsteinian and Eemian Interglacials have been recognized in the geological record of the Kleszczow Graben, central Poland. Two other temperate substages have been recognized on the basis of well-developed weathering horizons on the tills. The depositional environments and general petrological features of these sediments are described and their stratigraphical position is discussed. The Saalian Complex of the Kleszczow Graben has been subdivided into the Older Saalian (three glacial episodes), the Pilica Interstadial and the Younger Saalian (three glacial episodes and two presumed interstadials). This sequence cannot be simply correlated with other Saalian stratigraphic sequences in Europe, although the pre-Odranian and Odranian (=main Drenthe) tills most probably belong to the Older Saalian, and the Wartanian (Warthe) tills to the Younger Saalian. The geological record presented here suggests that reforestation phases occurred during the Saalian. This contradicts recently developed continental stratigraphics.

  • sedimentary successions in ice marginal fans of the late Saalian glaciation southwestern poland
    Sedimentary Geology, 2002
    Co-Authors: Dariusz Krzyszkowski
    Abstract:

    Abstract The Late Saalian end moraines of southwestern Poland contain several features that may be attributed to the formation that is predominantly controlled by the deposition of sorted (waterlaid) sediments. These hills are essentially small alluvial fans with ice-contact facies. They have a semi-conical form, plano-convex geometry, their distal slopes are up to 5°, and proximal slopes are between 5° and 20°. The sedimentary sequences contain two units: the lower unit comprises coarse-grained material of gravel-bed sheetflow facies and gravel-bed channel facies with subordinate high-energy channel flow facies and boulders up to 1.8 m in diameter. The upper unit contains sand-bed sheetflow facies and sand-bed channel facies. The sediment bedding is usually conformable with and parallel to the inclined fan surface. These sequences represent typical proximal–distal fan facies associations, with a high-energy and pulsatory water discharge in the proximal zone. The fans, in spite of their formation in the proglacial zone, have geomorphological features and sedimentary sequences that are very similar to present-day fans, and are equivalent to sheetflow-dominated or ‘humid’ alluvial fans in non-glacial environments.

  • the role of neotectonics and glaciation on terrace formation along the nysa klodzka river in the sudeten mountains southwestern poland
    Geomorphology, 2000
    Co-Authors: Dariusz Krzyszkowski, Boguslaw Przybylski, Janusz Badura
    Abstract:

    The Nysa Klodzka river drainage basin in the Sudeten Mts., SW Poland, preserves a complex late Cainozoic succession that includes eight fluvial series or terraces and deposits from two glacial episodes as well as local volcanic rocks, slope deposits and loess. Fluvial sedimentation took place during the Late Pliocene and from the early Middle Pleistocene (Cromerian), with a long erosion phase (gap) during the Early Pleistocene. Fluvial series are dated to the Late Pliocene, Cromerian, Holsteinian, late Saalian/Eemian, Weichselian, and the Holocene. Glacial deposits represent the early Elsterian and early Saalian stages. Almost all these stratigraphic units have been observed in all geomorphic zones of the river: the mountainous Klodzko Basin, the Bardo Mts. (Bardo gorge) and in the mountain foreland. The main phase of tectonic uplift and strong erosion was during the Early Pleistocene. Minor uplift is documented also during the post-early Saalian and probably the post-Elsterian. The post-early Saalian and post-Elstrian uplift phases are probably due to glacio-isostatic rebound. The Quaternary terrace sequence was formed due to base-level changes, epigenetic erosion after glaciations and neotectonic movements. The Cromerian fluvial deposits/terraces do not indicate tectonic influence at all. All other Quaternary terraces indicate clear divergence, and the post-early Saalian terraces also show fault scarps. The fluvial pattern remained stable, once formed during the Pliocene, with only minor changes along the uplifted block along the Bardo gorge, inferring an antecedent origin for the Bardo gorge. Only during the post-glacial times, have epigenetic incisions slightly modified the valley.

  • the intra Saalian interstadial floras of the chojny formation of belchatow central poland
    Journal of Quaternary Science, 1995
    Co-Authors: Dariusz Krzyszkowski, Małgorzata Nita
    Abstract:

    The Saalian sequence of Belchatow, central Poland, is exceptionally thick and complete. Five tills, two from the older Saalian (Odranian, Drenthe) and three from the younger Saalian (Wartanian, Warthe), which are separated by the fluvial Chojny Formation, have been identified. The Saalian sequence at Belchatow is underlain by Holsteinian and overlain by Eemian sequences, both palaeobotanically analysed. The Chojny Formation contains deposits of meandering (lower member) and braided (upper member) rivers, with occasional aeolian deposits. The lower member of the formation contains numerous organic layers. Pollen analysis indicates temperate (sub-boreal) to cold (sub-arctic) climatic conditions, with coniferous to mixed forests in the optimum phase of the interstadial. The interstadial floras of the Chojny Formation are interpreted as representing the intra-Saalian Pilica Interstadial. Profiles from Belchatow are designated as the stratotype profiles of this substage. The data from Belchatow show clearly that reforestation occurred between the major advances of the Saalian ice sheet, although only interstadial rank, not interglacial, may be inferred from the pollen data.

Related terms

Saalian - 15 days free trial to Access Experts & Abstracts