Criterion viii

Geology

The site, constituted of 9 different core areas, shows a practically continuous sequence of Upper Palaeozoic and Mesozoic rocks and therefore documents 200 Ma of earth history in a small and easily accessible area. In particular, the continental successions of the Permian and most of all the marine successions of the Triassic are a worldwide reference area for researchers and specialists of these periods. Significant intervals of the Triassic have been historically defined in these areas, for example: the Ladinian (term deriving from Ladinia), the Fassanian (from the Val di Fassa) and the Cordevolian (from the Cordevole Valley). The sites give the perception of geological and biological evolution in time together with a unique preservation of the original palaeo-environments, here spectacularly exposed preserving their original relationships and geometries; this allows an immersive experience unrivalled by any other place in the world. Its fossil “cliffs”, with atolls older than 200 Ma, are famous throughout the world, so perfectly are they preserved in their entire structure and beauty. Within the various areas that form this site, there are also a great number of fossiliferous sites of world-class importance for bio-chronostratigraphy and for palaeoecology studies.

General scientific reasons:

The steep cliffs coupled with only moderate disturbance by tectonics and, above all, the easiness of access has early attracted naturalists and geologists. The results of these pioneers still count among the classics in geology. Giovanni Arduino (1714-1795), Déodat-Guy-Silvain-Tancrède de Dolomieu (17501801), Alexander von Humboldt (1769-1859), Leopold von Buch (1774-1855), Edmund von Mojsisovics (1839-1907) and Ferdinand Freiherr von Richthofen (1833-1905) and many others paved the ground for future geoscientific research. The studies of these authors have been fundamental for the development of subjects such as stratigraphy, mineralogy, sedimentology and palaeontology. As an example, relations between intrusive and sedimentary rocks were here defined for the first time, clearly discarding the theory that all rocks were of sedimentary origin (the so-called Neptunist theory). Today the Dolomites continue to be a training and research ground for many scientists who come from all over the world for in-depth studying and to comparing notes on relevant geological matters. These zones are unquestionably a natural laboratory, which allows the great number of students and young researchers who visit these mountains every year, to see, to touch and to understand those geological phenomena that are documented here with extraordinary clarity.

Settsass viewed from Monte CastelloSettsass viewed from Monte Castello

Specific scientific reasons:

The Dolomites are an area of reference at worldwide level for the Triassic period. The documentation of the Triassic is extraordinary, because of the high sedimentation rates, and the enormous variety of depositional facies and environments. The abundant fossiliferous documentation makes this site one of the world reference areas for the biostratigraphy of the Triassic Tethys and testifies, in an outstanding way, the biological recovery after the most severe extinction in the Earth’s history at the end of the Permian Epoch. The Dolomites are the world´s only easy accessible area where large-scale Triassic carbonate platforms and their adjoining basinal areas can be observed in natural transects. This represents a unique opportunity for the whole Mesozoic Era. Another exceptional aspect that characterizes this area is given by the interrelationships between carbonate rocks and igneous rocks, here superbly outcropping in an alpine, but still easily accessible, terrain. Finally, the Dolomites are the type area of the mineral dolomite, first described in the 18th century, whose occurrence is enigmatic still at the present time. The excellent outcrops shall provide a huge natural laboratory for the solution of the “dolomite problem”.

Geomorphology

The Dolomites have an outstanding universal value also from the geomorphological point of view: they make up a unit of representative morphostructural and morphoclimatic genesis, which results from the complex geological structure of these mountains and past and present climate conditions. They are a sort of geoheritage high-altitude field laboratory, ideal for research, education and the development of geomorphological theories and understanding. Furthermore, they are a particularly representative case of geo(morpho)diversity, in every extrinsic or intrinsic meaning, at different scales. Finally, they show their geomorphological particularities in the midst of a landscape which is among the most spectacular in the world.

The landforms of the Dolomites show important peculiarities which, apart from creating a spectacular landscape, make them a unique natural site of exceptional scientific and educational value from the geomorphological point of view. They have, in fact, a wide and exemplary range of geomorphological phenomena resulting from the complex geological structure of these mountains and from the past and present climatic conditions. Indeed, they are a sort of high-altitude geo
heritage field laboratory of outstanding universal value, ideal for research, education and the development of geomorphological theories and understanding. In particular, the wide range of Dolomite landforms can be considered both from the morphostructural and morphoclimatic point of view. From a morphostructural viewpoint, the configuration of the reliefs in the Dolomite region shows a clear relationship with tectonics and lithology. There are landforms linked to tectonic movements (morpho-tectodynamics), such as fault scarps, morphotectonic lines, neotectonic evidence, stream piracy etc., and also someindications of relationships between erosion, sedimentation and pedogenesis processes. Even more numerous are the landforms related to morphoselection, as regards both tectonics with a passive role (morpho-tectostatics) and rock composition (morpho-lithology). In the former case, more or less inclined structural slopes linked to the attitude of the strata can be observed, or fault-line valleys and a series of towers, steeples, crests and pinnacles, in correspondence with rockfractures. In the latter case, typical landforms are those of the majestic sheer peaks overlying mild slopes or level fields, or ledges that gird many dolomite rock walls (“cengia”). In some places the rocks appear to be sculpted, cut or dismembered by several surface and subsurface karst processes. Among the landforms considered from the morphoclimatic standpoint, a wide and exemplary range of types linked to present-day climate conditions and those occurring during the latest geological epochs are present. Among the latter, erosion and accumulation landforms resulting from glacial and periglacial morphogenesis are frequently found, such as roches moutonnées, hanging valleys and moraine deposits, or traces of permafrost and cryoturbation, or, again, evidence of glaciopressure. These relict morphological features still condition geomorphological evolution, for example in the form of terraces or in relation to some mass movements. The morphology linked to recent and present-day climate conditions is of the frost- and snow-genesis type, such as talus cones and scree slopes, protalus ramparts, rock glaciers or avalanche traks and cones. Mass wasting makes a frequent occurrence, with all possible types of movement, up to very evident and spectacular cases, which have frequently been described in international scientific literature. Therefore, the Dolomites make up a unit of representative evidence from the scientific standpoint, with peculiarities that are particularly interesting from the educational standpoint. They are concentrated in a territory of exceptional universal value. The peculiarities, variety and reciprocal relations between the various land units which make up these unique mountain systems represent an exemplary case of geo-(morpho)-diversity, in every possible meaning. First of all, on a global scale the Dolomites show extrinsic geodiversity, this characterises and distinguishes them from all the other mountains of the world. Even on a regional scale there are landforms which show extrinsic geodiversity. These are mainly the structural landforms of morphotectodynamic genesis (fault scarps, morphotectonic lines, neotectonic evidence etc.), morphotectostatic genesis (structural slopes, fault-line valleys, towers, steeples, crests, pinnacles etc.) and morpholithological genesis (majestic sheer peaks overlying mild slopes, plateaux, ledges etc.). These components intersect with others which show high intrinsic geodiversity, that is, make up a unit of high educational and scientific value owing to their variety and complexity. At a regional level, glacial and periglacial landforms and especially mass movements can be quoted, which include practically all geomorphological combinations of landslides described in literature, as regards typology, cause, age, lithology, movement, extent etc. At a local level, the wide range of surface and subsurface karst landforms is particularly significant as example of intrinsic geodiversity. In addition, there are also other components which, on a detailed scale are characterised by accentuated uniformity or nearly exclusivity: these show a low degree of intrinsic geodiversity, such as talus cones and scree slopes which gird the feet of most of the Dolomite massifs. The characteristics of this geodiversity have been, from case to case, one of the geomorphological keys for the description of each System. Finally, it should be pointed out that thanks to all these morphostructural, morphoclimatic and geo(morpho)diversity peculiarities the Dolomites are a landscape well-known and admired in every corner of the world.