DOLOMITES:UNESCO: THE RIO DELLE FOGLIE GRAND CANYON
TRENTO - Aeons of erosion in a deep gorge in Italy's Dolomite mountain range have exposed layers of prehistoric rock strata important for documenting fossil remains of prehistoric vertebrate life, according to geologists and earth scientists. Surveys by the International Union for the Conservation of Nature (IUCN) found evidence of the earth's formation in strata so intact that the rock structure can almost be leafed through like the pages of a book, revealing not only how they were created but what the climate and environment was like 250 million years ago.
The Rio dello Foglie/Bletterbach gorge in Alto Adige, the Grand Canyon of the Dolomites, is a site of incomparable geological value, experts say. The meandering gorge was cut by the Rio delle Foglie river over the course of millennium, excavating an eight kilometre, 400 metre deep ravine and bringing to light a cross section of geological strata from the Permian and Triassic geological periods. The area, looking over the Valle dell'Adige just south of Bolzano, covers 271 hectares and is the smallest of the nine mountain groups included in Italy's bid for its Dolomite range to be named a United Nations World Heritage Site. In 1972 an international treaty to identify and protect cultural and natural heritage was adopted by the United Nations Educational Scientific and Cultural Organization (UNESCO).
The mission to preserve the world's heritage sites with outstanding value to humanity is carried out by the World Heritage Committee, scheduled to rule on the Dolomites by the end of June. Italy moved a step closer to its goal of getting the famous mountains a spot on the prestigious list in May when the IUCN endorsed its 2008 application. Nine mountain groups have been selected as representative of two UNESCO criteria: superlative natural phenomena and outstanding examples representing major stages of the earth's history. The small Rio delle Foglie/Bletterbach group - referred to by both its Italian and German names and protected as a natural monument by provincial legislation - is bordered by the villages Aldino-Aldein and Redagno-Radein, one on each side of the canyon, by Mount Pausabella-Schoenrast and the Oclini-Jochgrimm Pass. Overall, the area's peaks are more modest in comparison to the other groups; the only notable summit is the Corno Bianco-Weisshorn at 2,317 metres above sea level. The entire area is part of the Rio delle Foglie-Geoparc Bletterbach Geological Park which offers visitors a spectacular natural history route.
A walk through the park is a journey back in time and includes comprehensive notice boards set up along the path to explain the succession of geological eras from the Early Permian to the Middle Triassic. The cataclysmic, and still mysterious, 'Great Dying', when nearly all the earth's plant and animal life was lost in a mass extinction event occurred in the passage from one era to the next. The layers of rock and sediment testify to the various stages in the earth's evolution, from the volcanic rock in the Atesino Vulcanic Group, the result of a volcanic eruption 280 to 260 million years ago, to the clay and sandstone conglomerate (Val Gardena Sandstone) deposited during the advancing and receding of the Permian Sea in what was an arid tropical environment. Of the many fossilized traces of plants and animals preserved in the layers, a whole small reptile cast was an exceptional find. Further along the gorge a splendid succession of land and sea environments are conserved in rock strata from the Lower Triassic period - a remarkable representation of this key period in the planet's history.
The Val Gardena Arenaria in the Rio delle Foglie is internationally famous for its many footprints of extinct vertebrates and the number of plant fossils it has conserved from prehistoric eras. The extraordinary variety of extinct plant casts makes this site one of the most important Permian outcroppings in the world.
