noun[mass noun] Geology
- A series of sedimentary rocks, chiefly red sandstones, belonging to the Devonian system of NW Europe.More example sentences
- 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.