This system is made up of two vast dolomite plateaux (Gardenaccia and Sass di Putia/Peitlerkofel/Pütia), isolated by sheer escarpment ledges and surrounded by some of the highest, most majestic and typical peaks of the Dolomites (Sassongher, Puez and Sass Rigais). This can be considered one of the most characteristic landscapes of all these mountain ranges. From a morphotectonic viewpoint, there is no particular evidence of landforms related to neotectonics, apart from an alignment marginally affecting the system to W. This is a NNW-SSE striking fault line which affects the Alta Val Badia area along the ideal alignment «Col da Oi – Gardenaccia mountain hut – Col Alto – Incisa Pass – Salvazza stream». This fault has had important direct geomorphological consequences, such as the formation of numerous fault planes and fault escarpments, or some fault ravines, as well as indirect ones, such as the development, all along the fault alignment, of numerous, extended, deep-seated gravitational deformations. All the data and morphoneotectonic and geological evidence collected suggest that the fault was indeed active during the Pleistocene and, maybe, the Holocene, with a predominant right strike-slip movement. Another characterising element of this system is high relief energy compared with the surrounding territories.Seceda, Buchenstein Fm From a morphotectostatic viewpoint, the most evident morphostructure is Vallonga, set on a fault line sub-parallel to the important syncline line of Gardenaccia. This is a deep furrow, about 6 km long and 500 m wide, which cuts across the western part of the Gardenaccia plateau from SW to NE. This fault line continues to NE, as shown by a sequence of steps, saddles and canyons, as far as the boundary of the system. Another important E-W trending tectonic alignment runs along the Funes valley and separates the complex of the Sass Rigais, Puez and Gardenaccia mountains from the Sass de Putia plateau. It is put in evidence by the Funes valley, the saddle of Poma Pass and the portion upstream of the Torrent Longiarù. Other similar landforms are frequent especially in the lower portion of the area. Morpholithology evidence is frequently found on a small scale, e.g. the contrast between the mild porphyry slopes of Rasciesa and the dolomite escarpments of Odle, Puez–Gardenaccia and Sass de Putia. The latter correspond to some of the most representative structural plateaux in the whole region. On Gardenaccia a representative example of morphoselection can be observed between the flat surface of the plateau and a spectacular overhanging cone developed in the varicoloured Marne del Puez. On the surface of the dolomite plateaux (e.g., Gardenaccia) there are also some superficial karst forms, but these are less developed than in other dolomite areas of the region. Scree slopes and protalus rampart on Juel valleyFrom a morphoclimatic viewpoint, glacialism has left plenty of evidence of its presence. From the LGM Pleniglacial only a few traces are found. These consist of rare, isolated pebbles of allochthonous material from the crystalline bedrock above Lech de Ciampei, or pebbles mixed with autochthonous debris near Gardena Pass. The latter indicate glacial transfluence from Val Gardena to Val Badia. Other similar, significant traces have been found in the surrounding areas as on the Pralongià plateau, SE of the system. This kind of evidence has allowed the elevation line reached by glaciers during the LGM and their flow direction to be traced. In particular, the most widespread evidence, in the form of glacial cirques and moraine deposits, was left during the Lateglacial phase. Among the former, the Puez, Ciampei and Sass Rigais forms can be quoted. Among the latter, there are moraine ridges and arcs stretching from Puez and Longiarù crest to the valley to NE, in the direction of Longiarù. Other well preserved glacial forms are found in the small Chedul and Juel valleys, which stretch to W and E of Gardenaccia, respectively. The correlation between all these pieces of evidence has allowed a reconstruction of glacial evolution comparable with other areas of the Dolomites. There are numerous talus cones, scree slopes, protalus ramparts and avalanche debris, connected to glacionival morphogenesis. There are also mass movements affecting the dolomite walls in the form of rock falls or, from their foot, debris flows or earth flows. An example of a vast rock fall is the one occurring some 5000 years B.P. on the Sass Ciampac dolomite escarpment, which discharged its material as far as the village of Colfosco and beyond. The landslide age was detected by means of radiometric methods on spruce trunks found within the landslide body. Other landslides occurred at Piz Sompluf, at mount Cir, near Gardena pass, and from the W boundary of the System, towards Corvara in Badìa. The first is a rock fall occurred on 20 July 2006 at Piz Sompluf in the Community of S. Martino in Badia. It is an emblematic example of recent rock falls probably favoured by permafrost degradation and frost shattering processes. A volume of 40,000 m3 detached from a vertical cliff made up of Cassian Dolomite, at a height of 2400 m. The fallen material travelled for a distance of 800 m on the debris cone at the foot of the slope. The upper part of the Passo Gardena landslide is a significant example of rock slide affecting the Cassian Dolomite. In the Upper Badia Valley. It evolves into a rotational slide affecting weak clayey rocks of the S. Cassiano and Wengen formations, and then becomes an earth slide – earth flow of some million m3 of clayey material (cosmogenic 36Cl AMS dating: from about 11,800 to 8500 yr BP).Fault line valley of VallongaThe Corvara landslide affects an area of more than 2.5 km2 located immediately uphill of the village of Corvara in Badia (Pralongià plateau), at the SE boundary of System 6. It can be classified as a rotational earth slide, which locally shows evidence of earth flow, giving to the landslide a complex style of activity. It affects slopes made up of the Wengen and San Cassiano formations. The estimated overall volume is of more than 300 million m3. It is known from several radiocarbon dates that the landslide has moved since at least about 10,000 cal BP, and that it underwent a second major phase of morphological development from about 5000 to 2500 cal BP. The landslide is active at present, with movement rates ranging from about 0.01 to 2 m/year. The components of high extrinsic geodiversity, especially at a regional level, are found in the relief energy of the whole system, compared with the surrounding valleys, and in many examples of morphostructural landforms. The geomorphological data from this area, concerning the intrinsic geodiversity for morphoclimatic landforms and in particular numerous kinds of evidence of LGM and Lateglacial glacialism, have allowed an important paleogeographic reconstruction of the LGM and the subsequent deglaciation phase, with extrapolations also in other sectors of the Dolomites.

System 6