The Jura Mountains (Jura Massif, ) are a sub-alpine mountain range, a short distance north of the Western Alps, and mainly demarcate a long part of the French–Swiss border. While the Jura range proper ("folded Jura", ) is located in France and Switzerland, the range continues northeastwards through northern Switzerland and Germany as the Table Jura ("not folded Jura", ), which is crossed by the High Rhine.
Name
The first use in English of the name was in 1829 in the Proceedings of Geological Society. The mountain range gives its name to the French department of Jura, the Swiss canton of Jura, the Jurassic period of the geologic timescale, and the Montes Jura of the Moon. It is also known as the Jura Massif.
It is first attested as mons Iura in book one of Julius Caesar's Commentarii de Bello Gallico. Strabo uses a Greek masculine form ("through the Jura mountains", ) in his Geographica (4.6.11). Based on suggestions by Ferdinand de Saussure, early celticists such as Georges Dottin tried to establish an etymon "iura-, iuri" as a Celtic word for mountains, with similar putative etymologies (e.g. *juris, "mountainous forest") still appearing in more recent non-academic publications. However, since there are no clear cognates in the surviving corpus of the Celtic languages, modern studies of Proto-Celtic and Gaulish etymology tend not to list any lemmata connected to Jura, and the name must be considered fundamentally unclear.
Physiography
alt=A turquoise lake bordered by forested slopes and limestone cliffs in the Jura Mountains of France.|thumb|298x298px|View of Lac Nantua in the French Jura Mountains
The Jura Mountains can be regarded as part of the larger Central European uplands, associated with the mountain building of the Alpine orogeny and the European portion of the Alpide belt. The Jura range proper lies in France and Switzerland.
In France, the Jura covers most of the Franche-Comté region, stretching south into the Rhône-Alpes region and north into the Grand Est region. The range reaches its highest point at the Crêt de la Neige (), in department of Ain, west from the Swiss border of the canton of Geneva, and finds its southern terminus in the northwestern part of the department of Savoie. The north end of the Jura extends into the southern tip of Alsace (Sundgau). Roughly of the mountain range in France is protected by the Jura Mountains Regional Natural Park.
The Swiss Jura is one of the three distinct geographical regions of Switzerland, the others being the Swiss plateau and the Swiss Alps. Most of the range covers the western border with France. In Switzerland, the Jura Mountains extend over an area covering (from northeast to southwest) the cantons of Zurich, Aargau, Basel-Landschaft, Solothurn, Jura, Bern (i.e., Bernese Jura), Neuchâtel, Vaud, and Geneva. The easternmost mountain of the Jura range proper is the Lägern, situated east of the river Aare. Much of the Swiss Jura region has no historical association with Early Modern Switzerland and was incorporated as part of the Swiss Confederacy only in the 19th century. In the 20th century, a movement for Jura separatism developed, which resulted in the creation of the Canton of Jura in 1979.
The east of the Jura range proper separates the Rhine and Rhône basins. The northern and eastern part of the range drains towards the Rhine river and its tributaries Aare and Ill, whereas the western and southern parts drain towards the Rhône river and its (sub)tributaries Doubs, Saône, and Ain. Initially the river Doubs (a subtributary of the Rhône) flows about northeast, briefly venturing into Switzerland, then changing direction and flowing about southwest before joining the Saône ca. north of the French city of Lyon. In Lyon, the Saône joins the Rhône. While the Rhine flows into the North Sea, the Rhône flows into the Mediterranean Sea.
Northeast, the Jura range proper (known as "folded Jura", Faltenjura) is continued as the Table Jura (Tafeljura). The Table Jura ranges (from southwest to northeast) across the Swiss cantons of Basel-Landschaft, Aargau, and Schaffhausen (Randen), and the southern German states of Baden-Württemberg and Bavaria (as Klettgau Jura, Baar Jura, and the Swabian and Franconian plateaus).
thumb|upright|alt=Inward-curving cliff of the Creux du Van|[[Creux du Van]]
Geology
The range is built up vertically while decreasing in size laterally (along a rough northwest–southeast line). This deformation accommodates the compression from alpine folding as the main Alpine orogenic front moves roughly northwards. The deformation becomes less pervasive away from the younger, more active Alpine mountain building.