ABSTRACT
Nearly the entire oil production of France comes from Oligocene sand lenses in the Péchelbronn field in the Department of Bas-Rhin, Alsace, where it has been mined for many decades by means of shafts and galleries in addition to being recovered in recent years from wells. A total production of 12,210,000 barrels (1,720,209 metric tons) had been extracted from the field up to January 1, 1931. A relatively small amount of oil (19,038 metric tons or 141,600 barrels) has been extracted at Gabian, Department of Hérault, in southern France, where Triassic strata constitute the producing formation. A few barrels have been obtained by drilling in a graben in the Limagne (Auvergne) where large asphalt seepages are found surrounding volcanic necks in Oligocene sediments. Numerous asphalt seepages also exist in Triassic rocks throughout a belt paralleling the Pyrenees Mountains in the extreme southwest. Natural gas emerges from various Mesozoic and Tertiary strata in and near the southern extremity of the Jura Mountains, where the village of Ambérieu has been supplied with gas for years from several wells drilled near Vaux-en-Bugey (Vaux-Fevroux). Bitumen-impregnated sandstones of various ages are found in a belt along the east flank of the Jura. Although France contains several sedimentary basins in which possibilities of commercial oil exist, the tectonic conditions are in general complicated in the vicinity of the best indications. A vast amount of geologic work, and of geophysical work geologically directed, will be necessary in order to make discoveries, but new fields of commercial importance may ultimately be found.
