can result in objects lost within them reappearing many years later. The first recorded account of a body reappearing from a glacier in the Mont Blanc range was made by Viscount Edmond de Catelin in 1861. It concerned three alpine guides who were buried in a crevasse during an avalanche on 20 August 1820 near the Rocher Rouges, high up on Mont Blanc, during an expedition organised by . Forty years later the remains of two of them were discovered, re-exposed within fissures in the Bossons glacier. They were lower down from the point where they were lost; the corpse of the third guide was discovered the following year. In 2014, a group of climbers found a body on the Glacier du Talèfre, close to the Couvercle Hut. It was identified as that of a young Chamonix guide who had been caught in a winter storm during a solo ascent of the Nant Blanc face of the Aiguille Verte in 1982 and was assumed to have fallen into a crevasse. In 2013, a box of valuable gemstones was found by a climber on the Bossons Glacier. It had re-emerged, having been carried downhill from the site of one of two Air India plane crashes. These occurred at almost identical locations high up near the summit of Mont Blanc: one in 1950 (Air India Flight 245), and one in 1966 (Air India Flight 101). Debris from these crashes is still commonly found on the glacier below. Geology The Mont Blanc massif consists predominantly of ancient granite rocks. The Alps have their origins 770million years ago when upheaval of the earth's crust lifted up schist, gneiss and limestone rocks. These were destined to form the base of the Alps range, and this period of upheaval ended 300million years ago. Granite intrusions and associated metamorphic rocks formed the base of the mountains we now call the Mont Blanc massif as well as the nearby Aiguilles Rouges. But these rocks were then heavily eroded away, eventually being ground down and inundated by the sea, so allowing sedimentary rocks to form. Then, once again, this part of the earth's crust was uplifted as a result of the collision of continental plates. The huge mountain ranges of today's Alps began to form. This happened towards the end of the Tertiary period, 15million years ago. Finally, came the Quaternary era, when successive ice ages saw vast glaciers