PDF Publication Title:
Text from PDF Page: 008
13 An Outstanding Mountain: The Matterhorn 193 Fig. 13.6 Close view of the Matterhorn summit, showing the boundary between the greenish orthogneiss of the Arolla series and the coloured paragneiss (pink and dark green) intermingled with silicate marble (yellowish) of the Valpelline series. The flat shoulder is due to a thin band of Mesozoic calcschists folded into the Arolla series. The base of the Valpelline series is a hundred metres higher (photo H. Rougier) it. This almost horizontal spine, rather sharp, is just a little raised at its ends, a hollow having allowed the guides of Valtournenche to put a cross there. 13.3.2 A Highly Eroded Mountain At the Matterhorn, instabilities are favoured by lithology. The mass of the Matterhorn’s schistose gneisses, very heterogeneous in detail, provokes numerous rockfalls and rockslides. Indeed, on the east face, the most sensitive to temperature variations, freeze-thaw alternation and gelifraction are a daily process. The Matterhorn pyramid is thus less coherent that one could imagine where the unin- terrupted, tireless work of erosion depending on weathering is in action. Cryoclasty is the fundamental agent of mountain dismantling. It causes the rock to burst, freeing blocks of any size. Anyone climbing the Hörnli ridge can see how unstable the rock mass is, with boulders of any size in balance: the impression is that of a dry stone wall that has collapsed. The pyramidal shape of the mountain and its isolation are two essential elements to explain remarkable aerological phe- nomena. The Matterhorn is not a barrier blocking the movement of atmospheric disturbances. On the contrary, there is a conjunction of aspirations on all four sides, which generate particularly violent storms provoking, on the east side mainly, runoff that wash away the wall. At the same time, the high temperature gradient increases gelifraction of fractured rocks and favours the presence of snow on all sides, giving the mountain a very aesthetic “plastered” appearance. In this sense one can consider that the Matter- horn is a very lively mountain in all seasons, with the effects of cryoclasty predominating in summer and avalanches in winter. At the foot of the walls, the rimayes of the glaciers, —that are crevasses located at the upper limit of a glacier between the moving ice and the non-moving environment, usually rock, ice attached to the rock or neve—, which hemt the pyramid (e.g. Figure13.3) receive a high quantity of stones which feed their contents in morainic material. Selective erosion is the major factor in the contemporary evolution of the Matterhorn pyramid, with three clearPDF Image | An Outstanding Mountain The Matterhorn
PDF Search Title:
An Outstanding Mountain The MatterhornOriginal File Name Searched:
MatterhornOutstandingMountain.pdfDIY PDF Search: Google It | Yahoo | Bing
Cruise Ship Reviews | Luxury Resort | Jet | Yacht | and Travel Tech More Info
Cruising Review Topics and Articles More Info
Software based on Filemaker for the travel industry More Info
The Burgenstock Resort: Reviews on CruisingReview website... More Info
Resort Reviews: World Class resorts... More Info
The Riffelalp Resort: Reviews on CruisingReview website... More Info
CONTACT TEL: 608-238-6001 Email: greg@cruisingreview.com (Standard Web Page)