摘要:

The results are reported of a study of plant remains from the gastrointestinal tract of large herbivorous mammals, i.e., horse, mammoth, bison, which perished, according to C14data, during various periods of the Kargin interglacial in the Indigirka River basin (corresponding to the mid‐Wisconsin, 45,000 to 30,000 BP). At that time, the forest reached the coast of the Arctic Ocean, and bogs spread. This led to a reduction of herbaceous communities serving as pastures. The qualitative composition of the food of the animals changed. Plants of moist and waterlogged communities, sedges, cotton‐grass, grasses, and green and sphagnum mosses, began to predominate in their fodder. These communities differ considerably in their content of major nutrients (protein, albumin, fats) and mineral composition from plants of dry habitats and meadow forbs. This was the main reason for the reduction in the population of some animals and the final extinction of others.

ISSN:0273-8457    

DOI:10.1080/10889378109388689

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A discussion of the pollen sequence in loess and interstadial organic silts (thaw‐lake deposits, peat and organic loess) distinguishes two types of spore‐pollen spectra. One is close to the spectra found on the present southern margins of the tundra zone; the second has no present‐day analogs and reflects landscapes that were not only treeless, but shrubless, with a predominance of grasses (tundra‐steppe). The sequence from tundra spectra on the bottom to tundra‐steppe on the top can be traced in the thickest sections. Vast areas in the maritime lowlands of Yakutia consist of a unique, up to 60 m thick sequence made up mainly of aleurites and containing a large amount of segregation ice, particularly polygonal vein ice. This sequence is known as the Oyogos, Mus‐Khaya, Vorontsovo, and Yedoma formation in various parts of the lowland. The name “glacial sequence”;, as proposed by P. A. Solov'yev for similar sequences in central Yakutia, is quite suitable as a collective term.

ISSN:0273-8457    

DOI:10.1080/10889378109388690

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Radiocarbon datings and paleobotanical information, including some of the pollen data reported in the previous article, are used to revise the periodization of Late Pleistocene sequences in northeast Siberia. They yield four climate‐stratigraphic units that correspond to cooling trends (glacial stages) and warming trends (interglacials). The revised chronology suggests that, despite some distinctive features in the vegetation of northeast Siberia, its Pleistocene evolution conformed to that of other parts of the Northern Hemisphere and was evidently subordinated to climate fluctuations of global scope.

ISSN:0273-8457    

DOI:10.1080/10889378109388691

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

It is suggested that the low‐pressure region around Antarctica is associated with a field of negative gravity anomalies. Similar geophysical conditions have been found to prevail in the Greenland region in the Northern Hemisphere, where a thick ice sheet has formed. It is therefore concluded that present geophysical factors are sufficient to explain the paleoclimate of Antarctica and that the Antarctic and Greenland ice sheets could have been formed under atmospheric circulation and climatic conditions similar to those now prevailing on earth.

ISSN:0273-8457    

DOI:10.1080/10889378109388692

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

An equation is proposed for calculating the pollutant budget of the Arctic Ocean, and its application is illustrated on the basis of data for oil pollution.

ISSN:0273-8457    

DOI:10.1080/10889378109388693

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The impact of oil spills on Arctic water and ice was investigated in 1978 on three test plots on the drifting station North Pole 22 when it was 115 to 250 nautical miles north of Canada and Alaska. Oil products spilled on the surface of snow and ice were found to raise the surface temperature in spring to 5.3°C. The melting of the snow and ice cover was found to be more rapid in polluted plots than in clean plots, with the acceleration greatest in a plot polluted with crude oil and smallest with gasoline. These effects apply only to the particular conditions in the area of investigation. Similar tests elsewhere in the Arctic may yield a more generalized model.

ISSN:0273-8457    

DOI:10.1080/10889378109388694

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A 200‐m ice core obtained in 1976 on the Lomonosov Plateau in Spitsbergen is compared with isotope profiles obtained at the Camp Century and Crete stations on Greenland and on Devon Island as well as temperature curves for Iceland and England. All of them clearly show a cool 19th century and a warm 16th century. The Spitsbergen data, both for 1730–1890 and for the 13th‐15th centuries, come closest to those for the two Greenland stations. The Spitsbergen hole also suggests warm conditions for the 12th century, similar to the march of temperature in Iceland, although the warm period in England was 100 to 150 years longer.

ISSN:0273-8457    

DOI:10.1080/10889378109388695

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0273-8457    

DOI:10.1080/10889378109388696

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor