The glaciation of the Highland Border district of south-eastern Perthshire

Abstract

Introduction. The purpose of this paper is a study of the late Glacial stages in the retreat of the last ice to occupy the area along the border of the Highlands from the River Isla in the east to the River Tay in the west. The last ice seems to have been of ice-sheet form emanating from an ice-centre in the south-west and it is the retreat of this ice mass, south-westward along Strathmore, with its consequent division along the Highland Border escarpment, which forms the main subject of this paper. It is hoped later in Part II. of this paper to trace the westward retreat of the Strathmore-Ice from the River Tay to the River Almond, with a description of the moraines and outwash fans of the Sma’ Glen and Upper Glenalmond. II. Previous Literature. Existing literature on this area is scanty being almost entirely confined to the Geological Survey Memoir on Sheet 55 where the Glacial Deposits are dealt with in a short section by Grant Wilson (5, pp. 135-145). P. Macnair in ‶Geology and Scenery of the Highlands,″ vol. ii. (3, p. 102), deals with the general glaciation of the Highlands, drawing attention to kames, and lateral and terminal moraines left by the retreating glaciers. Mention is also here made of the supposed lake terraces of Strathtay described by Grant Wilson (5), doubt being thrown upon their mode of origin as lake-shore deposits and an alternative suggestion advanced that they are not lake but river terraces. Dr