GTN CycleTours
Tour du Vercors Nord
The Tour
du Vercors Nord, from 9th to 16th June 2007, costs £475
and will
be based in
a gîte in the northern Vercors village of Meaudre in the
980 metre high Meaudre valley between the 1600 metre high Clapiers
and Moliere ridges.
The
Vercors is a limestone plateau upland 60 kilometres north to south and
40 kilometres east to west, tapering to 10 kilometres at the northern
point and is part of the chain of PréAlpes limestone uplands
which extend
from the Swiss border near Geneva to Vaucluse plateau
near Avignon and continue past Nice to Italy.
The PréAlpes were formed in the Secondary Era from about 200 to 65 million years ago, when there was a sea where the Alps now stand. The Alps are where the European and African plates of the Earth's crust meet and were crumpled up in the Tertiary Era (65 to 2 million years ago) under pressure from the Italian side.
The Vercors is encircled by a mountainous ridge at up to two thousand metres high within three rivers - the Rhône to the west, the Isère to the north and the Drôme to the south - making the Vercors an easily defended natural fortress with only a handful of entrances. Throughout history the occupants have asserted their opposition to outside oppression - whether medieval warlords refusing the King or the French Resistance opposing the German invasion during the Second World War. There are two narrow and steep ways into the Vercors from the north: through the Gorge of the river Furon or the 1100 metre crossing of the end of the Montagne de Lans ridge to the head of the Bourne valley. There is also the Tunnel du Mortier at the top of the Meaudret valley but the road is permanently blocked by a landslide on the north side. The 2000 metre high Montagne de Lans ridge forms a natural barrier to any easy access to the Vercors from the east.
On the western side, the ridge is pierced by the only
valley road into the Vercors in the spectacular gorges of the
River Bourne, and the steep and narrow gorges of the
Vernaison river in the many tunnels of the Grands Goulets,
the Gorges du Nan and the Canyon des Ecouges.
The three river valleys within the Vercors - the Bourne, the Meaudret and the Vernaison - are at 800 to 1000 metres and run north or south until they all turn west and meet at the Bourne gorge. The Bourne river is the only way out for the Vercors rain, which ends up in the Isère river to the west and, via the Rhone river, in the Mediterranean at the Camargue region near Marseille.
Most of the Vercors is within the Parc Naturel Régional du Vercors
which
was formed in 1970 to balance the ecological and economic needs of the
area.
Limestone uplands like the Vercors usually have extensive caves formed from water erosion by the underground rivers, and many are accessible. The Vercors is renowned for its caves and the best known is the Gouffre Berger which held the deepest underground exploration record of 1200m for many years.
The Grottes de Choranche in the Bourne gorge has an outer cave which
is
readily accessible, but the inner cave with considerable stalactites
requires a
guided tour.