Dulhunty, J. A. On glacial lakes in the Kosciusko Region. Journal and Proceedings Royal Society of New South Wales, Vol. 79, Pt. IV, 1945 (published 1946), p. 143–52.
From an examination of the contours and soundings made with a specially contrived apparatus, it is concluded that abnormal conditions of vegetation and soil formation existing on the undissected, glaciated surface of the Kosciusko region have been responsible for the survival of alpine lakes throughout the post-glacial period.
[G. S.]
Hough, Jack L. Pleistocene lithology of Antarctic ocean-bottom sediments. Journal of Geology, Vol. 58, No. 3, 1950, p. 254–60.
Three ocean-bottom core samples were obtained from within the pack-ice area in the mouth of the Rosa Sea, Antarctica, during the U.S. Navy Antarctic Expedition of 1946–47. These cares consist of several alternations of glacial marine sediment and of fine-grained sediment which apparently is nonglacial. Age determinations of the material, made by Dr. W. D. Urry, provide a time scale on which the lithology may be plotted. Because the cores record periods of from one hundred and seventy thousand to over a million years, a record of the Pleistocene glacial history of Antarctica is provided. A comparison of this with the record for the Northern Hemisphere indicates that glaciation was contemporaneous in the two hemispheres.
[Author’s abstract.]
Lawrence, Donald B. Estimating dates of recent glacier advances and recession rates by studying tree growth layers. Transactions, American Geophysical Union, Vol. 31, No. 2, Pt. 1, 1950, p.243–48.
Study of the growth layers of trees growing along the margins and below the terminus of a present-day receding glacier reveals the minimum lapse of time in years since the glacier advanced beyond a given point, and the approximate rates at which recession has occurred. Study of cross sections of trees pushed part way over by ice pressure at the time of maximum glacier advance and left in a tilted position to continue growth until the present, discloses the exact year of the maximum advance. This is detected through a change in form of growth layers in the trunk cross section. Growth while the tree is erect is concentric about the growth center; that after trunk tilting is asymmetric. The non-conformity between concentric central growth and eccentric outer growth marks the year of the tilting. This technique and others described here may be used to date landslides, windstorms, and river floods as well as glacier fluctuations.
[Author’s abstract.]
Thompson, H. R. Some corries of north-west Sutherland. Proceedings of the Geologists’ Association, Vol. 61, Pt. 2, 1950, p. 145–55.
Among the conclusions of the author are the following: Quartzite breaks up more readily than gneiss under the influence of melting and re-freezing. The effect of moving ice on gneiss is largely confined to polishing and sapping. Rock basins in come floors may possibly have been formed in pre-glacial times, but were more probably excavated by debris-armed ice, the action of which may have been that of rotational slipping.
[G. S.]
Viete, Günter. Ueber die allgemeine atmosphArische Zirkulation während der diluvialen Vereisungsperioden. Tellus, Vol. 2, No. 2, 1950, p. 102–15.
The range of polar cold air over the northern hemisphere was increased during the glacial periods primarily due to the extension of the large ice shields. Particularly in the north Atlantic region the atmospheric centers of action and the storm tracks were shifted southwards, the meridional temperature gradient was strengthened and consequently the general circulation increased. This intensification of the large scale exchange of air does not contradict the recent increase of the general circulation and its consequences, since during the glacial periods the increase was of a compulsory and secondary nature caused by the ice extension itself. On the contrary the atmospheric circulation at the beginning of the glaciation must have been decreased. However, the continued extension of the Scandinavian ice shields, as well as the creation of the Keewatin and Labrador shields in North America and the North Asian glaciation, occurred during periods of secondarily increased circulation. An examination of the most important Ice Age theories shows that the primary weakening of the circulation may be satisfactorily explained only by assuming a decrease of the earth’s solar radiation supply. The astronomical Ice Age theory is applicable only in connection with the assumption of an uplift of the IcelandFaerisland submarine ridge.
[Author’s abstract.]
Wiseman, J. D. H., and Ovey, C. D. Recent investigations on the deep-sea floor. Proceedings of the Geologists’ Association, Vol. 61, Pt. 1, 1950, p. 28–84.
It is becoming evident that in order to interpret correctly the earth’s history it is necessary to investigate the deep-sea floor, which covers approximately two-thirds of the earth’s surface. Owing to the great increase of bathymetrical soundings with the development of the echo-sounder and the publication of hathymetncal charts, it has been possible to develop a rational classification of deep-sea morphological features. The origin of these features is discussed.… As satisfactory methods have now been developed for obtaining long cores from the deep-sea floor it is possible to investigate past oceanic history as far back as the Pliocene. The various methods by which past oceanic history may be revealed are described.… The use of radium determinations for marine chronology is discussed.… The use of planktonic foraminifera in the interpretation of chemical changes from washed core samples is discussed. Brief notes are given concerning the individual planktonic species used as temperature indicators. A short survey of the implication of chemical changes from a study of the deep-sea floor is given, mentioning a few of the theories advanced to account for them in the Pleistocene and the dangers of arriving too hurriedly at conclusions from the analysis of only a few cores.
[From authors’ abstract]
