/pdf/permafrost-conditions-in-the-mediterranean-region-since-the-2zzmboet16.pdf

Permafrost conditions in the Mediterranean region since the Last Glaciation

The consequence of assessing the natural and cultural heritage of a territory is the need of tools for their management. The European Geoparks Network and the Global Geoparks Network (assisted by UNESCO) have the function to provide these tools, aiming at promoting the sustainable development of a territory through the valorization and conservation of its natural and cultural heritage. Becoming an international recognised Geopark in 2005, the Beigua territory has gathered increasing attention from local authorities, tourism operators, entrepreneurs, universities and research institutions, schools, volunteers and environmental associations. During the last 5 years Beigua Geopark developed several projects and acted to raise public awareness on nature conservation. Thanks to effective collaboration with geoscientists, local authorities and tourism organisations, Beigua Geopark set up a structured network of interpretation facilities to support geotourism activities. In this direction, Beigua Geopark also launched an organised touristic offer. Connecting landscape, cultural heritage, sports facilities with unique geological and geomorphological features, Beigua Geopark presents multiple services to encourage both local and regional sustainable development.

From Geoheritage to Sustainable Development: Strategies and Perspectives in the Beigua Geopark (Italy)

The weathering and origin of an autochthonous blockfield in the northern Swedish mountains were investigatedthrough an examination of fine matrix and clasts from two pits excavated across ridge-top ...

Weathering processes and Quaternary origin of an alpine blockfield in Arctic Sweden

Two small blockstreams, the first such landforms to be recorded in the mountains of Scandinavia, are described from Insteheia, a col at 910 m asl on the watershed between Valldalen and Tafjorden (More og Romsdal), southern Norway. Both blockstreams display morphological and sedimentological characteristics indicative of boulder accumulations that have moved downslope by means of solifluction most probably under a permafrost climatic regime. These comprise boulder preferred orientation and dip patterns; inverse grading comprising surface boulders overlying successively finer, well-sorted cobble, pebble and finegrained (sand/silt dominated) sediment layers; imbrication, with the packing of small boulders behind larger boulders; and proximity to boulder-strewn hillslopes whose constituent boulders (organised into lobes and terraces) feed downslope into the blockstreams. Schmidt-hammer exposure-ages of 7.24 to 11.17 ka indicate that the blockstreams were last active during the Younger Dryas Stadial – Holocene transition (~9.5-11.2 ka). It is inferred that blockstream development began at ~18 ka, following the Last Glacial Maximum, and lasted for ~8 ka, and that since the blockstreams became inactive fine grained material has been progressively lost as a result of snowmelt runoff. The small areal extent and relatively recent age of the blockstreams contrast with larger-scale forms of considerably greater age in the Southern Hemisphere.

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Relict blockstreams at Insteheia, Valldalen-Tafjorden, southern Norway: their nature and Schmidt-hammer exposure age.

Mapping of over 4000 block deposits and scree slopes in eastern Australia is used to determine the extent of past strong freeze-thaw activity. Freeze-thaw landforms are common in the high country as far north as 30 degrees S. There is a clear association between the locations of relict periglacial landforms and areas that receive more than 50 modern frost days. We infer about 10.5 degrees C cooling north of 35 degrees S in the Diving Range, about 9 degrees C in the Australian Alps and about 5 degrees C in Tasmania during the phases when the lowest block deposits were active. An unexpected observation is the importance of precipitation in the distribution of block deposits north of 35 degrees S. Here, the majority of block deposits have a southerly or westerly aspect, and lie in a narrow modern precipitation band of ca. 900-1050 mm. To the east, high-elevation areas appear to have weaker diurnal oscillations limiting freezethaw activity. To the west, block deposits are absent, probably due to insufficient moisture to drive freeze-thaw processes. We cannot define specific last glaciation precipitation but the maintenance of a strong east-west precipitation gradient during glacial times is consistent with the maintenance of onshore easterlies during cold periods. Copyright (c) 2015 John Wiley & Sons, Ltd.

The distribution and climatic implications of periglacial landforms in eastern Australia

The area around Monte Beigua is characterized by accumulations of large blocks. Survey indicates the occurrence of flow structures on the surfaces of the blockfields, and a pattern of long axis orientation aligned in the same direction as the local gradient. Blocks are often imbricated upslope at the front. The formation of block streams is tentatively attributed to cold-climate conditions during the Pleistocene. Copyright © 2006 John Wiley & Sons, Ltd.

M. Guglielmin

Papers

Relict blockfields in the Ligurian Alps (Mount Beigua, Italy)