Contributions to the geomorphology of the North York moors
This thesis is a geomorphological study of Eskdale, a drainage basin in the North York moors. The aims of the study are to examine the potentiality of the technique of morphological mapping as a basis for quantitative study in geomorphology, to consider some of the factors which affect angle of slope and to elucidate the development of the physical landscape within the drainage basin. There is a general relationship between angle and area of slope in a drainage basin; as angle increases above one degree the area of slope decreases. A regression is derived to express this relationship. Distributions of angle of slope plotted against area of slope for certain controlled conditions are obtained and compared with the results from the drainage basin framework. Eskdale was drained by a major eastward - flowing consequent stream in early Tertiary time which was superimposed upon the underlying geological structures. Three planation surfaces were produced after the mid - Tertiary earth movements. During the production of the most recent of these, which developed in two parts as partial peneplains, specific drainage changes occurred and these are analysed in detail. The Quaternary sequence of stages in valley development is considered for the main valley. The mode of decay of the last ice sheet in the area is examined. Stagnant ice formed throughout the area during deglaciation but its formation was preceeded by two stages of ice - marginal drainage in eastern Eskdale.The major landforms introduced by periglaciation are considered and the variation of angle of slope with different values of orientation analysed. This shows that not one direction, but several, suffered oversteepening after the last glaciation. Finally, an analysis of mass movements which occurred during 1960 - 1961, largely as a result of exceptionally high rainfall, is made.