The Lochaber Series South of Loch Leven, Argyllshire

Abstract Detailed mapping of a small area has shown that the Eilde Schist undergoes marked variations of facies when traced southwards from Loch Leven. Through the appearance of interbedded quartzite the normal schist of the western outcrop passes into a banded facies, while much of the banded facies of the eastern outcrop is believed to pass into massive quartzite mapped as Elide Quartzite. This sedimentary transition, rather than tectonic causes, probably accounts for the rapid variations in thickness of the two stratigraphical units. An additional factor controlling the thickness of the Elide Schist belonging to the eastern outcrop is the existence of an erosional surface at the base of the succeeding Binnenian Quartzite. The possible significance of these factors in the geology of the country north of Loch Leven is discussed briefly with special reference to some of the minor slides.