In a gravel pit near Hultsfred, at the eastern margin of the South Swedish Upland, gravelly, sandy and silty-sandy beds covered by a thick, stratified gravelly diamicton are exposed. Large folds and ...shear-planes indicate post-depositional deformation of the sorted sediments, which according to OSL dating have a maximum Middle Weichselian (∼60 ka) age. The sand and gravel are interpreted as glaciofluvial sediments that were deposited laterally during a Middle Weichselian deglaciation, or possibly subglacially during the Late Weichselian. The large-scale deformation was due to glaciotectonics, caused by an overriding wet-based ice sheet during the last deglaciation. The subglacial hydrostatical pressure was high and led to the formation of downward-injected clastic dykes. A basal till, which forms the cover moraine in the area, caps the succession. The fairly frequent occurrence of sub-till sediments on the South Swedish Upland demonstrates the limited effect of glacial erosion in parts of this area. During the Last Glacial Maximum, the South Swedish Upland was an 'island' of slow-moving, polythermal and at least partly non-erosive ice, surrounded by faster ice-streams in the Baltic and in the Skagerrak. The ice sheet may have left its main impact on the landscape during short periods during advance and deglaciation only.
The overall pattern of deglaciation of the southern part of the Scandinavian Ice Sheet has been considered established, although details of the chronology and ice sheet dynamics are less well known. ...Even less is known for the south Swedish Upland because the area was deglaciated mostly by stagnation. Within this area lies the conspicuous Vimmerby moraine, for which we have used the terrestrial cosmogenic nuclide (
10
Be) exposure dating technique to derive the exposure age of six glacially transported boulders. The six
10
Be cosmogenic ages are internally consistent, ranging from 14.9 ± 1.5 to 12.4 ± 1.3 ka with a mean of 13.6 ±0.9 ka. Adjusting for the effects of surface erosion, snow burial and glacio-isostatic rebound causes the mean age to increase only by c. 6% to c. 14.4± 0.9 ka. The
10
Be derived age for the Vimmerby moraine is in agreement with previous estimates forthe timing of deglaciation based on radiocarbon dating and varve chronology. This result shows promise for further terrestrial cosmogenic nuclide exposure studies in southern Sweden.
Based on studies of striae in the Kvarken area in the northern part of the Baltic basin, and re-interpretation of stratigraphic sequences earlier interpreted as evidence of a readvance of the ice ...margin in the Gulf of Bothnia a model for the deglaciation of the Gulf is proposed. The model implies quick break-up of the ice due to areal thinning of an ice lobe in the Gulf and change from cold-based to warm-based ice. Wide calving bays were formed close to and into the centre of the ice in the northern part of the Gulf. The change of balance caused sudden collapses in the centre followed by surges upon the warming base of soft ductile sediments. The effect was a westward shift of the ice centre from the Gulf area towards the mountain range. The ice sheet changed from a thick one with a subaquatic margin into a thin, terrestrial one, thus becoming more sensitive to the rising temperature at the end of the Weichselian glaciation.
The Quaternary history of northern Sweden as known today is based on studies on glacial landforms and Quaternary deposits. In these studies the north-eastern part of the County of Norrbotten has been ...of special interest since landform systems of different age occur in the region. This article focuses on Veiki moraine, a type of hummocky moraine of pre-Late Weichselian age. Veiki moraine has a distinct distribution pattern, showing the ice margin of a decaying pre-Late Weichselian ice. A sediment core from within a Veiki moraine plateau at Rissejauratj was studied by means of pollen analysis. The pollen assemblages at Rissejauratj are dominated by Betula pollen and correlate with spectra from the warmest Weichselian interstadial periods recognised at other sites in northern Sweden. The Rissejauratj sequence can be correlated to either (1) the middle part of the first Weichselian interstadial (Tärendö I), (2) the early phase of the second Weichselian interstadial (Tärendö II), or (3) the late phase of the second Weichselian interstadial (Tärendö II). If alternative 3 is correct the ice sheet that formed the Veiki moraine was small and probably did not reach outside the eastern limit of Veiki moraine distribution.
Neanderthals and Modern Humans develops the theme of the close relationship between climate change, ecological change and biogeographical patterns in humans during the Pleistocene. In particular, it ...challenges the view that Modern Human 'superiority' caused the extinction of the Neanderthals between 40 and 30 thousand years ago. Clive Finlayson shows that to understand human evolution, the spread of humankind across the world and the extinction of archaic populations, we must move away from a purely theoretical evolutionary ecology base and realise the importance of wider biogeographic patterns including the role of tropical and temperate refugia. His proposal is that Neanderthals became extinct because their world changed faster than they could cope with, and that their relationship with the arriving Modern Humans, where they met, was subtle.
The monograph Drobci ledenodobnega okolja (“Fragments of Ice Age environments”) presents a compilation of seventeen chapters in which experts from different scientific fields discuss specific topics ...related to the Ice Age in Europe. Ten of them are devoted to the presentation, analysis and interpretation of palaeontological data concerning various large mammal species ranging from mastodon and mammoth to the cave hyena, ibex, cave lion and bears, with the emphasis being placed on the cave bear. Several chapters address the topic of Last Glacial climatic conditions in the Southeastern Alps by studying fossil micromammal and palaeobotanical remains as well as geoarchaeologiocal data. A special article is devoted to a comprehensive review of previous analysis of the bone flute from Divje babe I, but includes also new musicological research findings on the extraordinary technical capabilities of this oldest musical instrument. The concluding chapter presents a study of old manuscripts and printed sources, providing some interesting insights into the discovery of one of the most significant palaeontological sites in Slovenia - the cave of Mokriška jama.The monograph is dedicated to the anniversary of the prominent researcher of the Slovenian Palaeolithic - Ivan Turk. His work, main achievements and selected bibliography are briefly presented in the introductory chapter.
Ventifacts occur frequently in extensive areas in northern and central Sweden. They arose during severe periglacial conditions in the Weichselian Tärendö interstadial and their presence indicates ...that the latest ice sheet was incapable of reshaping earlier deposits or even significantly after the interstadial ground surface in these areas. Accordingly, the ventifacts not only witness to harsh climatic conditions during part of the Tärendö interstadial but also reflect the limited erosional capacity of the latest ice sheet. Their significance as stratigraphic markers and means in the search for pre-Late Weichselian organic sediments, serving as archives for past climate and environment, is emphasized.
Since the rapid rate of global warming at the onset of the Bølling interstadial became evident, its cause has been under debate. It coincides closely in time with a strong global transgression called ...meltwater pulse 1a. One attempt at solution says that a meltwater pulse of Antarctic origin could cause an increase in North Atlantic Deep Water formation, and thus give rise to the Bølling interstadial. However, others have disputed that Antarctic meltwater would have that effect, and furthermore, the start of the Bølling interstadial is not even associated with an increase in North Atlantic Deep Water. A controversial hypothesis says that some Laurentian meltwater came from a jökulhlaup (sub-glacial outburst flood), but no study has yet shown unequivocally that sufficient amounts of water could be stored under the ice. Furthermore, according to all available data a melt-water pulse from the Laurentian ice would give rise to strong cooling, not warming. Nevertheless, meg-afloods appear instrumental in accumulating the Mississippi Fan, created entirely during the Quaternary period, and dramatic climate changes are characteristic of this period. This paper presents a hypothetical chain of events, building on the published literature and simple calculations, to investigate whether the order of magnitude is reasonable. The hypothesis is that a jökulhlaup from a Laurentian captured ice shelf flowed out through the Mississippi, boosted the Gulf Stream, reinvigorated the North Atlantic circulation, and as a result triggered the Bølling warm phase.
Prispevek obravnava kronologijo mlajšega pleistocena (MIS5-3, ”izotopske stopnje” 5-3) v Sloveniji na podlagi paleolit-skih jamskih najdišč. Glavni poudarek članka je na metodolo-giji in ...terenskih tehnikah. V prvem delu je podan kritičen pregledstanja do leta 1990, ko je avtor prevzel vodenje paleolitskihraziskav. V drugem delu so predstavljeni nova kronologija inustrezni stratotipi najdišča Divje babe I. Najbolje je predstav-ljen stratotip MIS 3. S pomočjo kronometrije in klimatokro-nologije je najdišče primerjal tudi z drugimi stratotipi virmskepoledenitve
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