chalk formation वाक्य

In Europe, some of the best toolmaking flint has come from Belgium ( Obourg, flint mines of Spiennes ), the coastal chalks of the English Channel, the Paris Basin, Thy in Jutland ( flint mine at Hov ), the Sennonian deposits of R�gen, Grimes Graves in England, the Upper Cretaceous chalk formation of Dobruja and the lower Danube ( Balkan flint ), the Cenomanian chalky marl formation of the Moldavian Plateau ( Miorcani flint ) and the Jurassic deposits of the Krak�w area and Krzemionki in Poland, as well as of the L�gern ( silex ) in the Jura Mountains of Switzerland.