摘要:

AbstractThis article is the second in a series of articles (cf. Sundborg 1967) dealing with fluvial sediments and fluvial morphology and accounting for results of field research, experimental investigations and theoretical analyses conducted at the Geomorphology Laboratory in Uppsala. Black sand deposits in the valley of the river Luleälv are studied, and the hydrodynamical sorting and enrichment of heavy minerals is discussed. Grain size analyses and mineralogical analyses of heavy mineral samples have been performed. The mineralogical composition is discussed in connexion with a brief account of the general geological environment. Water velocities and grain size distributions, especially favourable for the enrichment processes are stated.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879778

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractIntermittent observations on the behaviour of 4 of the main glaciers on the Uganda slopes of the Ruwenzori are reported. While this does not represent a large sample of the 37 glaciers of the massif, it probably shows clearly the pattern of change at least on the eastern slopes. The glaciers examined were relatively active valley tongues whereas many of the so-called glaciers of the range are either summit icecaps or small cirque glaciers. Due to the smallness and steepness of the glaciers examined, they probably react rapidly to mass-budget changes. Such a supposition finds confirmation in the similarity of their behaviour. Over the period of observations rapid retreat is evident; this has been neither constant nor continuous. Speculations concerning the significance of these variations are offered.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879779

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractThe two main erosion surfaces of southern Uganda were both developed in relation to a westward flowing drainage system. In addition they were both distorted, though to a lesser degree in the case of the lower surface, by warping on the flank of the Western Rift Valley. Both of the surfaces are composed of a limited number of minor surfaces whose form is described. Because of the warping, correlation between residuals of these surfaces cannot be undertaken on the basis of absolute heights but has to depend on an analysis of surface form, surface materials, and local morphological relationships. Variations in the nature of the surfaces are examined, and their relationship to lateritic material is discussed. Correlations between the two major surfaces and those found in adjacent areas, together with an examination of their nature in southern Uganda, suggests that the highest surface is of pre-Tertiary age and that the lowest surface was developed between the pre-Miocene and the early Pleistocene.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879780

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractViews on the nature of vegetation alternative to the Clementsian monoclimax theory are presented. The rise of these more recent concepts (which have been neglected in the geographical literature) is traced: first that of the polyclimax, and secondly that of gradient analysis and the continuum. Some of the important studies which led to the formation of two opposed views, the‘ordination’school and the‘classification’school, are outlined. Recent attempts to test the suitability of both approaches and to clarify the issues involved are then discussed. In conclusion, some parallels with the development of geomorphology are stressed.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879781

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor

摘要:

AbstractAn attempt has been made to analyze the areal distribution of climatic features which influence man's comfort in Africa. Monthly and annual indices were applied to about 800 stations. According to the findings the year-round mildest regions occur in the eastern highlands and along cool-current coasts while greatest heat stress is experienced along the Red Sea, Gulf of Aden and interior Somalia.

ISSN:0435-3676    

DOI:10.1080/04353676.1968.11879782

出版商:Taylor&Francis    

年代:1968

数据来源: Taylor