[mass noun] A series of sedimentary rocks, chiefly red sandstones, belonging to the Devonian system of NW Europe.
- ‘However, the change in structural dip could reflect synsedimentary tectonics (and hence an intrabasinal unconformity developed entirely within an Old Red Sandstone succession), and the dykes may not be syndepositional.’
- ‘They concluded that the Bristol Channel Thrust juxtaposes the Devonian of north Devon and the Old Red Sandstone and Carboniferous of South Wales.’
- ‘The Stonehaven Group lies at the base of the Old Red Sandstone in the Midland Valley of Scotland and sits unconformably on the Highland Border Complex.’
We take a look at several popular, though confusing, punctuation marks.