Note 87 — Chapter XXXI · THE PERMIAN VOLCANOES OF SCOTLAND
Reading edition
In some recent borings around Hartlepool the Magnesian Limestone has been found to be interstratified with thick bands of gypsum and anhydrite, and to be overlain by more than 250 feet of the latter substance. Nothing could show more forcibly the exceedingly saline and insalubrious character of the Permian lakes or inland seas.