Sur l'age et l'extension des terrains houillers dans la terminaison sud de Belledonne (dome de La Mure et regions annexes); leurs rapports avec le socle cristallophyllien

Abstract The Carboniferous coal-bearing sequence in the southern Belledonne massif area, France, has previously been assigned only to the Stephanian A. Westphalian beds have been identified at the base of the sequence, separated from the overlying strata by a conglomerate. They are considered to have been deposited in a broad syncline between two zones of high relief resulting from crustal movements during the Sudetic phase of the Hercynian orogeny. Following recurrent crustal movements, the Stephanian sediments were deposited in a slightly broadened syncline. The folded and faulted coal basin was further compressed and fractured during Alpine orogenic activity.