The Aiguilles Marbrées (), (, literally "marbled needles") is a mountain peak in the

Mont Blanc massif The Mont Blanc massif (french: Massif du Mont-Blanc; it, Massiccio del Monte Bianco) is a mountain range in the Alps, located mostly in France and Italy, but also straddling Switzerland at its northeastern end. It contains eleven major indepen ...

, above the Glacier du Géant, with its summits forming part of the frontier between

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

and

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

. It is situated between the Col de Rochefort and the

Col du Géant The ''Col du Géant'' (''Giant Pass'') at is the main passage of the Mont Blanc massif between Courmayeur in the Aosta Valley and Chamonix-Mont Blanc in the Arve Valley. On the French side, to the north is the Géant Glacier which overlooks the ...

, and is easily accessed from the

Torino Hut The Torino Hut ( it, Rifugio Torino; French: ''Refuge Turin'') is a high mountain refuge in the Alps in northwestern Italy. Located near the border with France, it is about southwest of Mont Dolent, the tripoint with Switzerland. The refuge ...

Pointe Helbronner Pointe Helbronner () is a mountain in the Mont Blanc massif in the Graian Alps on the watershed between France and Italy. The peak, which used to be a mere geodetic reference point, was named after Paul Helbronner, a French '' polytechnicien'', ...

. Seen from the north, the mountain has a triangular appearance. It contains two summits, the northern one being the highest. The lower, southern summit () is separated by a broken rock ridge.

First ascents

The Aiguilles Marbrées was first climbed on 17 August 1876 by Lionel Dècle, Henry Devouassod and Edouard Coupelin, who reached its highest point via the NE slope. The first winter climb was made on 21 January 1907 by G. Carugati, Miss Carugati, Joseph Petigax and Laurent Petigax. The first ascent of the lower southern summit was made on 22 July 1989 by A. Hess, O. Leitz and Laurent Croux from the Col du Géant and E Arête. The summit is normally reached by an ascent of its northeastern ridge, from the Col de Rochefort (). The route is graded F+/PD- on the adjectival climbing scale. There are a small number of rock climbing routes on the mountain *North Summit (North-west ridge) Grade IV, one pitch of V. Height 270 metres, 3.5 hours (first ascent: G. Brignolo, Casteli and Marchiard, 1996) *North Summit (West spur) 8 pitches, one of grade V. 3 hours (first ascent: H Boisier, J Chaffat, 8 September 1979)

Geology

Geologically speaking, the Aiguille Marbrées is part of the 'Swiss Unit' of Mont Blanc, and consists mostly of medium to coarse grained

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies under ...

s, together with some porphyritic rocks.

Rockfall research

A series of major rock falls occurred on the north side of the Aiguille Marbrées in summer 2007. This led to investment by the local authorities in research and monitoring of the state of the mountain. Both conventional surveying and photogrammetry were employed in order to create a geo-referenced

digital elevation model A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete g ...

of the mountain. This helped researchers understand the reasons for the initial rockfall, as well as providing a baseline study for comparison with future surveys after subsequent rockfalls. ;Notes

References

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External links

Aiguilles Marbrées on French IGN mapping portal

Aiguille Marbrées on Google maps
Mountains of the Alps Mont Blanc massif