File:GSG GLA FIG 16 01.jpg

English: Figure.16.1. Explanation of the structural and stratigraphical context of the Upper Old Red Sandstone basin. A, Cross section, B, Interpretation of the upward fining megacycles in terms of contemporary faulting, C, Explanation of the regional control on the basin formation. A sinistral movement on a fault (the Highland Boundary Fault or some fault which may be associated with it) which has a bend in the region of Arran, caused extension in the areas a-b in Ci. There is extension here because it is difficult to move material on the south side of the fault around the bend at (a). Because of this extension there is a sequence of normal faults developed which form the basins at (d, e, f, g) (Cii) where (d) is the basin at Rosneath, (e) at Wemyss Bay and (f) at Portencross. (g) is a remaining source block on Arran. HBFZ, Highland Boundary Fault Zone; SUF, Southern Uplands Fault.

From: Lawson, J.D. and Weedon, D.S. (editors). 1992. Geological excursions around Glasgow & Girvan. Glasgow : Geological Society of Glasgow.