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JAN MANGERUD EILIV LARSEN ODDVAR LONGVA EIVIND SØNSTEGAARD 《Boreas: An International Journal of Quaternary Research》1979,8(2):179-187
The deglaciation patterns of the Bergen and Nordfjord-Sunnmøre areas in western Norway are described and correlated. In the Bergen area the coast was first deglaciated at 12,600 B.P., with a succeeding re-advance into the North Sea around 12,200 B.P. Later, during the Allerød, the inland ice retreated at least 50 km, but nearly reached the sea again during the Younger Dryas re-advance, ending at 10,000 B.P. Sunnmøre was ice-free during an interstadial 28,000–38,000 B.P. Later the inland ice reached the sea. The final deglaciation is poorly dated in Sunnmøre, while further south in Nordfjord, it started slightly before 12,300 B.P., followed by a major retreat. No large re-advance of the inland ice occurred during the Younger Dryas. However, in the Sunnmøre-Nordfjord area many local glaciers formed outside the inland ice during the Younger Dryas. Limnic sediments outside one such cirque glacier have been cored and dated, proving that the glacier did not exist at 12,300-11,000 B.P., and that it was formed and disappeared in the time interval 11,000–10,000 B.P. (Younger Dryas). The erosion rate of the cirque glacier was 0.9 mm/year. 相似文献
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JAN MANGERUD HANS-PETTER SEJRUP EIVIND SØNSTEGAARD SYLVI HALDORSEN 《Boreas: An International Journal of Quaternary Research》1981,10(2):137-208
A complete interglacial cycle, named the Fjøsangerian and correlated with the Eemian by means of its pollen stratigraphy, is found in marine sediments just above the present day sea level outside Bergen, western Norway. At the base of the section there are two basal tills of assumed Saalian ( sensu lato ) age in which the mineralogy and geochemistry indicate local provenance. Above occur beds of marine silt, sand and gravel, deposited at water depths of between 10 and 50 m. The terrestrial pollen and the marine foraminifera and molluscs indicate a cold-warm-cold sequence with parallel development of the atmospheric and sea surface temperatures. In both environments the flora/fauna indicate an interglacial climatic optimum at least as warm as that during the Holocene. The high relative sea level during the Eemian (at least 30 m above sea level) requires younger neotectonic uplift. The uppermost marine beds are partly glaciomarine silts, as indicated by their mineralogy, drop stones and fauna, and partly interstadial gravels. The pollen indicates an open vegetation throughout these upper beds, and the correlation of the described interstadial with Early Weichselian interstadials elsewhere is essentially unknown. The section is capped by an Early Weichselian basal till containing redeposited fossils, sediments, and weathering products. Several clastic dikes injected from the glacier sole penetrate the till and the interglacial sediments. Radiocarbon dates on wood and shells gave infinite ages. Amino acid epimerization ratios in molluscs support the inferred Eemian age of the deposit. The Fjøsangerian is correlated with the Eemian and deep sea oxygen isotope stage 5e; other possible correlations are also discussed. 相似文献
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MADS HELLE EIVIND SØNSTEGAARD G. RUSSEL COOPE NORALF RYE 《Boreas: An International Journal of Quaternary Research》1981,10(4):369-379
Stratigraphical investigations of an inter-till peat in Brumunddal suggest a major interstadial of Early Weichselian age. The insect fauna and the pollen composition indicate a mean July temperature 2–3C lower than today during the climatic optimum. Larch and spruce immigrated at the end of the interstadial, which is tentatively correlated to the Jamtland Interstadial. 相似文献
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EIVIND ØSTBYE STEIN-ERIK LAURITZEN KJARTAN ØSTBYE ØYSTEIN WIIG 《Boreas: An International Journal of Quaternary Research》2006,35(2):296-316
Norwegian caves contain stratigraphical information regarding the historical faunal composition valuable in the assessment of postglacial colonization and phylogeographical structure. In some of these limestone caves, brown bear ( Ursus arctos L.) remains have been excavated and radiometrically dated. We present osteology (95 traits defined) from 29 brown bears found within 22 Norwegian caves above 658N. Our data span the time interval 6210–420 14 C yr BP. The sex of individuals was based on dimorphic canines, while age was determined by cementum analysis and body size estimated from regressions between morphological traits compared to a contemporary reference collection. Five females and 14 males were recognized, while the remaining bears could not be sexed because of their small size, low age or lack of canines. The ages of 26 bears (tooth cementum age and estimates) ranged from juveniles (<0.5 year) to adults (23 years), the majority being old animals. Both sexes have used these caves for over-wintering lairs, as seen in several caves, where denning is also suggested based on the observations of adult females and cubs. There were no signs of predator or human transported bear remains, suggesting natural mortality. The age of the bears suggests that young or old bears may have died from insufficient nutrient storage, environmental harshness, or may have drowned in spring or autumnal flooding. We conclude that Norwegian brown bears have used these caves sporadically for thousands of years, which suggests that caves are not a preferred site for the brown bear during hibernation or denning. 相似文献
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JAN MANGERUD STEINAR GULLIKSEN EILIV LARSEN ODDVAR LONGVA GIFFORD H. MILLER HANS-PETTER SEJRUP EIVIND SØNSTEGAARD 《Boreas: An International Journal of Quaternary Research》1981,10(4):447-462.
Seven localities with fossil-bearing tills were found in the Ålesund area. Fifteen radiocarbon dates of marine shells in the tills all gave ages between 28,000 and 38,000 years B.P. In spite of a general scepticism to shell dates giving high finite ages, these ages may be accepted mainly because of the quality of the shells, the geological situation in which they were found, and identical results for different fractions. The ice-free period is named the Ålesund Interstadial. and its Middle Weichselian age is also suggested by amino acid D/L ratios in shells, compared with Late Weichselian and Eemian ratios. Shell and foraminifera faunas suggest arctic conditions with the Atlantic water present during the optimal period. The tills are non-sorted, compacted and interpreted to be basal tills. Their age is bracketed between c. 28,000 and 12,800 years B.P. 相似文献
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The effect of egg volume on body mass, body composition and growth rate in arctic tern Sterna paradisaea chicks was studied at Ny-Ålesund, on Svalbard (78°55'N, 12°00'E), in order to investigate whether differences in egg size influence the physiological characteristics of the hatchlings. The relative content of yolk and albumen in eggs did not vary in proportion to egg volume. Hatchlings from large eggs had larger body masses than hatchlings from small eggs, with 71% of the overall variation in body mass accounted for egg volume. In newly-hatched chicks, water content, lean body and total lipid mass, as well as both leg and pectoral muscles, changed isometrically in proportion to egg volume. Hatchlings from large eggs, however, had disproportionately larger yolk sacs. The leg muscles of small chicks contained a lower proportion of water than the leg muscles of large chicks, indicating that the leg muscles of small hatchlings were functionally more mature. There was a weak, but significant, correlation between egg volume and growth rate. However, a residual analysis made to eliminate the effect of egg volume showed no correlation between hatchling body mass and growth rate. The results of the present study show that Arctic tern hatchlings from large eggs emerge with more yolk sac reserves, enabling them to better withstand periods of food-scarcity. During embryonic growth in small eggs, however, there seems to be a greater relative usage of yolk, resulting in a more developed leg musculature. This may partly compensate for the higher mass-specific heat loss in small hatchlings. 相似文献
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EIVIND ØSTBYE STEIN-ERIK LAURITZEN DAGFINN MOE KJARTAN ØSTBYE 《Boreas: An International Journal of Quaternary Research》2006,35(1):142-158
The faunal composition and temporal species succession dynamics during the Holocene are poorly known in Norway, and interpretations are often biased because of the potential overrepresentation of game species in the archaeological finds. Pitfall traps in limestone caves represent less biased long-term records of fauna, often being excellently preserved for thousands of years and thus providing an opportunity for reconstruction of the postglacial distribution history. We excavated fossiliferous sediments at the bottom of a 40-m entrance shaft, functioning as a pitfall trap, in the Sirijorda Cave, northern Norway, comprising 3467 identified vertebrate bone fragments. Radiocarbon-dating of mammalian bones at stratigraphic levels in excavated trenches was used for calibrating the time scale during the last 8000 14C years BP, with a reconstruction of local vegetation history from a pollen profile in the cave deposits. At least 20 species were identified: one frog, two birds (plus 1-2 to genus level) and 17 mammals. Most of the species appeared more or less continuously during the covered time periods of the Atlantic, Subboreal and Subatlantic chronozones. With the exception of one species, Sorex isodon, which seems to have disappeared during the past 2000 years, all the registered species in the time profile are present in the area today. The possible immigration routes and time periods for (re)colonization of the recorded species are discussed. 相似文献
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