Old Red Sandstone
Proper noun
Meaning
Old Red Sandstone
A red sedimentary rock formation in Britain.
Examples
Before his first visit to England in 1834, the labours of Hugh Miller and other geologists brought to light the remarkable fish of the Old Red Sandstone of the northeast of Scotland.
In nineteenth-century texts the Devonian has been called the "Old Red Age", after the red and brown terrestrial deposits known in the United Kingdom as the Old Red Sandstone in which early fossil discoveries were found.