Statistical analysis of till fabric: methodology, local and regional variability (with particular reference to the north Yorkshire till cliffs)

Abstract

Three distinct stages of folding have been recognized in the area investigated. The earliest folds (F1), on approximately ENE.–WSW. axes, are (from south to north) the asymmetrical Creag na h-Iolaire anticline closing to the south, the Sròn Mhòr syncline, and the asymmetrical Loch Tummel anticline which closes to the north. The Creag na h-Iolaire anticline is correlated with the Aberfoyle anticline (Shackleton 1958). To the north of the River Tummel the general structure consists of a series of overturned folds, whose axial planes dip to the south (cf. Bailey 1925); according to A. L. Harris considerable northward movement has taken place here on a series of south-dipping slides. The Sròn Mhòr syncline occupies a central position between the two sets of oppositely directed overfolds, and represents the highest structural level exposed in the area. This fold is comparable in structural position with the Loch Awe syncline.