Rugose corals are common fossils in rocks of Ordovician to Permian age.

Numerous Archimedes species occur worldwide in rocks of Carboniferous and Permian age.

The reservoir is sealed by thick, impermeable Kungurian salt of Permian age.

Lamprophyre dykes of Late Permian age are found throughout Orkney.

They are all composed of granite of early Permian age.

They were thought at that time to be the British version of Germany's Rotliegendes, which is in fact of Permian age.

There are no local rocks of Carboniferous or Permian age.

Locharbriggs is from the New Red Sandstone of the Permian age.

They are Rio do Rastro Formation and Late Permian age.

The tunnel is 132 yards long and was built through magnesian limestone of Permian age, referred to locally as "chalk".