New information from borings shows that in the region to the west and north of the Lons-le-Saunier basin, France, the Jura border is thrust over the Tertiary of the Bresse region. The age of the movement is post-Pontian, and the amplitude over five kilometers at certain points. The movement occurred along gypsum and salt zones in the lower Keuper and Muschelkalk (Triassic) without disturbing the underlying Triassic, Permian, and Carboniferous beds.

Borings in the Lons-le-Saunier region, France, show that thrusting of the western border of the Jura massif over the Bresse Tertiary formations took place over a surface which was eroded in the Tertiary and partially covered by conglomerates.

Study of different claystones in the Stephanian (Carboniferous) deposits of the Lons-le-Saunier coal basin, France, shows that they retain certain features over relatively long distances. The x-ray diffraction pattern, in particular, is often typical of a given claystone. Kaolinite is practically the only clay mineral present. The claystones must have been derived from the soil cover of a continental land area.

Paleobotanic evidence confirms the presence of a lower and a middle Stephanian zone in the Carboniferous coal measures of the Lons-le-Saunier coal basin (Jura, France).

The Stephanian (Carboniferous) barren measures of the Lons-le-Saunier basin, France, consist of two large groups of rocks. Those of the first group are feldspathic and are the product of the breakdown of denuded parent rock; those of the second group, without feldspar, are derived from soil which had developed on similar parent rocks. Enallaxy is the alternation of these two types. Accumulation of the barren measures can be explained in terms of slow and continuous subsidence. Formation of coal seams, however, requires the conditions resulting from more or less sudden subsidence.