The Mals Heath () is located in

South Tyrol South Tyrol ( , ; ; ), officially the Autonomous Province of Bolzano – South Tyrol, is an autonomous administrative division, autonomous provinces of Italy, province in northern Italy. Together with Trentino, South Tyrol forms the autonomo ...

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 one of the largest ancient landslides and one of the most remarkable landscape features in the Alps. It is located in the Upper

Vinschgau The Vinschgau, Vintschgau () or Vinschgau Valley ( ; ; ; medieval toponym: ''Finsgowe'') is the upper part of the Adige or Etsch river valley, in the western part of the province of South Tyrol, Italy. Etymology The German name ''Vinschgau'', li ...

where a broad pass (the

Reschen Pass Reschen Pass (, ; ) is a mountain pass across the main chain of the Alps, connecting the Upper Inn Valley in the northwest with the Vinschgau region in the southeast. Since 1919, the border between South Tyrol, Italy and Tyrol, Austria has app ...

) crosses the main Alpine divide into the

Inn Valley The Inn (; ; ) is a river in Switzerland, Austria and Germany. The long river is a right tributary of the Danube, being the third largest tributary of the Danube by discharge. The highest point of its drainage basin is the summit of Piz Bernin ...

(

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

). It extends from

Glurns Glurns (; ; ) is an urban ''comune'' (''Stadt'') in South Tyrol in northern Italy, located about northwest of Bolzano. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy"). Geography As of 30 November 2010, it ha ...

via Laatsch, Schleis, and Burgeis up to Plawenn. On the southern part is the village of

Mals Mals (; ) is a ''comune'' (municipality) and a village in South Tyrol in northern Italy, located about northwest of Bolzano, on the border with Switzerland and Austria. History Coat-of-arms The emblem is party per fess: the upper of gules a ...

. The height difference of the heath varies from 900 m (Glurns) to 1,760 m (Plawenner Alm). The landslide emerges from the small side valley of Plawenntal, and descends for 11 km to the head of Vinschgau proper. The volume of the debris fan is estimated at 1,650 million cubic metres. It had always been assumed to be an alluvial fan, built up by numerous floods and debris small flows. New research demonstrates that a lost mountain could have existed above the head of Plawenntal, with a summit at about 3,100m - the present highest peak on the perimeter being the Mittereck, 2,908 m. There are indications all around the perimeter of a catastrophic collapse, severing former ridges and valley heads (notably Vivanatal). The shape of the lost mountain can readily be reconstructed by projecting these truncated landforms until they meet up. The volume of the lost mountain (named Plawennspitz) is very close to that of Mals Heath. There is at present no evidence of when this event occurred, but probably soon after the last glacier melted, over 10,000 years ago. Similar events probably created large fans nearby at St. Valentin, and in the main Vinschgau, notably at Allitz- Laas (Gadriamure) where the lost mountain and vast debris cone are even larger. Other megafans in the Alps are likely to be catastrophic too (1).Jarman D, Agliardi F, Crosta G (2011): Megafans and outsize fans from catastrophic slope failures in alpine glacial troughs: the Malser Haide and the Val Venosta cluster, Italy. Geological Society Special Publication 351, pp 253-278 The Mals Heath used to be a barren heath since it was so free draining. The debris fan dams a lake,

Haidersee The Haidersee () is a lake in South Tyrol, Italy, which belongs to the municipality of Graun im Vinschgau Graun im Vinschgau (; ; ) is a ''comune'' (municipality) and a village in South Tyrol in northern Italy, located about northwest of B ...

, which is now used as a source of irrigation water through a system of channels, and nearly all the heath is now cultivated and prosperous. The fan also displaces the main river,

Adige The Adige is the second-longest river in Italy, after the Po. It rises near the Reschen Pass in the Vinschgau in the province of South Tyrol, near the Italian border with Austria and Switzerland, and flows through most of northeastern Italy ...

, and the large tributary, Puni, to opposite sides of the valley. Disastrous floods still occur, destroying houses and even villages. The main road climbs the fan in broad zigzags, not the usual hairpins of an alpine pass, with several large wind turbines taking advantage of the smooth terrain and natural wind funnel.

References

{{coord, 46, 43, 10, N, 10, 32, 39, E, region:IT-BZ_type:landmark_source:kolossus-dewiki, display=title Geography of South Tyrol Landslides in Italy