Geology and Climate

Gneiss up north, granites in the centre, sedimentary rocks of volcanic origin down south make up the Hautes-Vosges bedrock. These remain from a vast and ancient hercynian mountain formed over 400 to 500 million years. However, today’s mountain shapes are much younger. They come from the raising and dislocation of the ancient base shaped by the Alps formation. The old mountain did indeed rise a second time – but its centre dislocated and collapsed into tiers to form the Rhineland rift. The Vosges and the Black Forest appear respectively West and East. Erosion and glaciers shaped the sceneries we can admire today. The last ice age ended 12,000 years ago. The Hautes-Vosges Mountains is surprisingly prolific in varied natural environments thanks to relief, geological variations, and first and foremost climatic conditions – themselves subject to topography, altitude or orientation. As a result, the Hautes-Vosges stand in the way of oceanic perturbations from the West. Winters are cold and summers cool (11 °C on average instead of 20 °C in the Alsace Plain). Rains are substantial with sometimes more than 2 meters of water per year on the crest, instead of a little over 50 cm in Colmar – one of the driest regions in France.