The Aiguilles Marbrées (), (, literally "marbled needles") is a mountain peak in the
Mont Blanc massif, above the
Glacier du Géant, with its summits forming part of the frontier between
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
and
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
. It is situated between the
Col de Rochefort and the
Col du Géant, and is easily accessed from the
Torino Hut at
Pointe Helbronner.
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 (phanerite, phaneritic) intrusive rock, 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 coo ...
s, together with some porphyritic
Porphyritic is an adjective used in geology to describe igneous rocks with a distinct difference in the size of mineral crystals, with the larger crystals known as phenocrysts. Both extrusive and intrusive rocks can be porphyritic, meaning ...
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
Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and patterns of electromagnetic radiant ima ...
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, Natural satellite, moon, or asteroid. A "global DEM" refer ...
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.
References
{{reflist
External links
Aiguilles Marbrées on French IGN mapping portal
Aiguille Marbrées on Google maps
Mountains of the Alps
Mont Blanc massif