The Formation of the Bituminous Layers of the Middle Triassic of Ticino (Switzerland) (Abstract)
The black shales of the Middle Triassic of the Limestone Alps of Ticino are famous for their perfectly preserved marine vertebrates, reptiles and fishes. They are also well-known for their high content of organic matter (up to about 50%). The so-called Grenzbitumenzone is the most famous bituminous member within the Middle Triassic of the Ticino. It is situated at the boundary Anisian/Ladinian and well exposed near Serpiano at the Monte San Giorgio and at Besano (Italy). It consists of finely laminated, highly bituminous claystones, more or less laminated bituminous dolomites and some thin layers of argillaceous tuffites.