Monday, May 21, 2018

The Jura Mountains

While Switzerland is famous for its Alps, which cover the southern half of the country, it also harbors a second mountain range, the Juras, which stretch along its northwestern border with France.  More than 200 miles in length, the Jura Mountain Range arcs from the Rhone Valley, at Geneva, to the Rhine Valley, at Basel.

The Jura Mountains have a core and outcrops of marine Jurassic limestone, deposited in the Paratethys Sea when dinosaurs roamed the planet; these sedimentary rocks were uplifted during the Pliocene Period of the Cenozoic Era (some 5-2 million years ago) as pressure from the ongoing Alps Orogeny rippled the landscape to their north.  While Jura means forested or mountains in regional native languages, it is also the basis for the word Jurassic, a name chosen by geologists for the middle period of the Mesozoic Era.  The Jura mountains are indeed forested except for alpine grasslands on the higher summits and sheer rock cliffs on some of the mountain flanks; the highest peaks of the Juras are in the southwestern portion of the range but all are under 5700 feet in elevation.

While villages abound in the valleys, the rugged slopes of the Jura Mountains have limited development.  Ski resorts have been constructed in recent decades and both countries have established Nature Reserves along the range.  Of course, the limestone geology has also produced a wealth of karst features (caves, springs, underground streams) which attract visitors to the Juras.