6: The Dalradian rocks of the northern Loch Awe district

Abstract

Introduction In this guide accessible exposures of Middle and Upper Dalradian rocks (now respectively classified as the Argyll and Southern Highland Groups [Harris and Pitcher 1975]) in the northern Loch Awe district are described. The localities have been chosen so as to allow examination of each of the major lithological components of the succession. Furthermore, the outcrops allow the major structures of the region to be detected. Examination of the localities described requires two days. The best centre on which to base an excursion is Oban although Kilchrenan, Taynuilt and Connel also provide accommodation within the area. General Geology Within the present area (Fig. 2) the outcrop pattern of the Dalradian stratigraphy is controlled by the Loch Awe Syncline, a structure which was first described by Bailey (1913). The most north-easterly part of this structure is shown by the synclinal distribution of stratigraphic units shown in Figure 2. In detail the Loch Awe Syncline is a compound structure consisting of two synclines and an intervening anticline. These quite tight folds are slightly overturned to the south-east (Borradaile 1973) in contrast with the single broad, open, upright syncline indicated by Bailey. The axial traces of the component folds to the Loch Awe Syncline strike NE.-SW. and the more prominent syncline is the Kilchrenan Syncline. Its axial trace passes just to the west of Kilchrenan and the syncline appears to continue as the Tayvallich Syncline in the area to the south–west of that indicated in Figure 2. The Loch Awe-Tayvallich district . . .