Franco Gianotti

The Ivrea Morainic Amphitheatre as a Well Preserved Record of the Quaternary Climate Variability (PROGEO-Piemonte Project, NW Italy)

In the Piedmont plain of NW Italy the Ivrea Morainic Amphitheatre (IMA) is a remarkable evidence of the Quaternary glaciations. It consists of a wide (505 km2) complex of lateral moraines (i.e. the Serra d’Ivrea), end moraines and kame terraces, encircling a 200 km2 wide flat internal depression above which a subglacially moulded rocky hills (the Colli d’Ivrea) elevates. The glacigenic succession ranges from the end of the Early Pleistocene (dated on palaeomagnetic basis) to the end of the Late Pleistocene (14C radiometric and 10Be exposure ages) (about 900–20 ky BP). The IMA has recently been parted into ten stratigraphical units, potentially correlable to the whole sequence of the main Quaternary glaciations recorded by the marine oxygen isotope stratigraphy. Natural (glacigenic deposits and forms) and archaeological (i.e. the Roman gold mines) features make the IMA a very interesting topic for a multidisciplinary research with educational, cultural and tourist purposes. Some recent and present activities for the land promoting are presented. A candidature to the UNESCO global geopark network is considered as a suitable and ambitious goal.

The Monviso massif and the Cottian Alps as symbols of the Alpine chain and geological heritage in Piemonte, Italy.

In order to promote geosite conservation in the project entitled ‘PROactive management of GEOlogical heritage in the PIEMONTE Region’, we propose a comprehensive study involving the Monviso Massif (MM) geothematic area, one of the most outstanding symbols of the Alps and particularly of the Cottian Alps. Specifically, at the MM, the inventory of a number of different geosites whose conservation and development require different geologic and some additional non-geological expertise is considered: (1) some of the best preserved ophiolites in the Alps and the associated Cu–Fe mineralizations; (2) the lithostructural units in the Germanasca Valley; (3) the first primary source of jade in the Alps at the MM and its importance in terms of Neolithic to Bronze Age-polished stone implements; (4) the world-famous minerals such as coesite and giant pyrope, as well as type localities for new minerals (including carlosturanite); (5) the area, now buried under a debris flow, where Hannibal is thought to have regrouped his army while crossing the Alps; and (6) the biodiversity of lichens, microfungi and cyanobacteria colonizing the ophiolites, which can give additional value for the environmental assessment and evaluation of the MM outcrops. Following geodiversity identification, further stages will be devoted to develop appropriate plans for geodiversity conservation in this area.

The Morainic Amphitheatre Environment: A Geosite to Rediscover the Geological and Cultural Heritage in the Examples of the Ivrea and Rivoli- Avigliana Morainic Amphitheatres (NW Italy)

The Ivrea Morainic Amphitheatre (IMA), at the Aosta Valley outlet, and the Rivoli-Avigliana Morainic Amphitheatre (RAMA), at the Susa Valley outlet, are the two main and well preserved Pleistocene end moraine systems of the North-Western Italian Alps. These two morainic amphitheatres are geosites containing high environmental, naturalistic, landscape and cultural values. The comparison between the geological and geomorphological features of the two amphitheatres evidenced that they can be considered a unicum and a “not renewable resource”. Analyses of the relationships between man and the morainic environment put in evidence synergies and conflicts, exploitation and conservation in relation to geodiversity. A deeper knowledge of the territory within a holistic approach allows to increase a sense of responsibility towards it, to favour better perception of the environmental problems and to develop proper engineering solutions for territorial planning.

Distribution, Discharge, Geological and Physical–Chemical Features of the Springs in the Turin Province (Piedmont, NW Italy)

Numerous exploited springs (1571) have been investigated in the Turin Province. They have been mapped with a GIS on a new, specially drafted, geolithological map and statistically examined with regard to areal distribution, discharge, use and lithological composition of their catchment basin. One spring every 4 km2 occurs in this area. In detail, the spring density is greater in the mountains (1 spring every nearly 3 km2) than in the plains and in the hills (1 spring every 10–53 km2). These springs are well-distributed in the different altitude ranges, with two peaks at 800–1,100 m and at 140–300 m. They are mostly used for drinking water supply (65 %), irrigation (23.5 %), sanitary use (6 %) and, subordinately (5.5 %), industries, fish farms, production of electric energy and unknown use. The 54.7 % of the springs has discharge lower or equal to 1 l/s, while only the 2.7 % (43 springs) has discharge greater than 10 l/s. A 81 l/day drinking water supply each inhabitant is estimated per capita. The spring areal distribution into the different geolithological units and their discharge values (linked to the aquifer typology) are synthetized. A sample of 28 analyzed springs has bicarbonate to sulfate alkaline-earth facies. Their electric conductivity (100–400 μS/cm) is due to content of bicarbonates (mean value of 100 mg/l) and sulfates (mean value of 15 mg/l). In a single basin (Dora Riparia) the Total Hardness exceeds 25 French Degrees.

ERT geophysical surveys contributing to the reconstruction of the geological landscape in high mountain prehistorical archaeological sites (Plan di Modzon, Aosta Valley, Italy)

One of the few examples of high mountain prehistorical archaeological sites in northern Italy has been discovered within the so called Plan di Modzon area, at 2300 m a.s.l., in the Aosta Valley (Western Alps). This area shows interesting geological features and morphological evidence which have been recently linked to a wide Deep-Seated Gravitational Slope Deformation (DSGSD). A probable filled lake and the presence of buried landforms have been also hypno tized on the basis of geological observations, resulting in the need for new devoted surveys to confirm these hypotheses. A better and comprehensive understanding of the geological evolution of the area is indeed necessary to allow a precise reconstruction of the environments in which man has inhabited these territories. Combined Electric Resistivity Tomographies (ERT) and geological surveys have been therefore used to better define the occurrence and nature of morphological evidence along the western slope of the filled lake, in which one of the archaeological sites has been discovered and excavated. The outcomes of the integration of the two surveys is a more refined definition of the geological forms, in respect to the one previously assumed on the basis of surface surveys only. Indeed, ERT revealed buried zones with low resistivity associable to the presence of sliding surfaces and also showed the geometry and thickness of the sediments within the filled lake. Geological surveys also evidenced a DSGSD evolution in the area constrained to Lateglacial, because of the lack of particularly evident gravitative forms, i.e. remodeled by glacial abrasion.

Use of water resources in mountain. The case study of the Montellina Spring.

Lucchi, Renata G. ... et. al.-- 87° Congresso della Societa Geologica Italiana e 90° Congresso della Societa Italiana di Mineralogia e Petrologia, The Future of the Italian Geosciences - The Italian Geosciences of the Future, 10-12 September 2014, Milan, Italy.-- 1 pageThe Montellina Spring (370 m a.s.l.) represents an example of groundwater resource in mountain region. It is a significant source of drinking water located in the right side of the Dora Baltea Valley (Northwestern Italy), SW of Quincinetto town. This spring shows a morphological location along a ridge, 400 m from the Renanchio Torrent in the lower sector of the slope. The spring was investigated using various methodologies as geological survey, supported by photo interpretation, structural reconstruction, NaCl and fluorescent tracer tests, discharge measurements. This multidisciplinary approach, necessary due to the complex geological setting, is required for the importance of the Montellina Spring. It is interesting in the hydrogeological context of Western Alps for its high discharge, relatively constant over time (average 150 l/s), and for its location outside a fluvial incision and suspended about 40 m above the Dora Baltea valley floor (Lasagna et al. 2013). According to the geological setting, the hydrogeological reconstruction of the area suggests that the large amount of groundwater in the basin is essentially favoured by a highly fractured bedrock, covered by wide and thick bodies of glacial and gravitational sediments. The emergence of the water along the slope, in the Montellina Spring, is essentially due to a change of permeability between the deep bedrock and the shallow bedrock and/or surficial sediments. The deep bedrock, showing closed fractures and/or fractures filled by glacial deposits, is slightly permeable. The shallow bedrock, strongly loosened as result of gravitational phenomena, and the local gravitational sediments are, on the contrary, highly permeable. The concentration of water at the spring is due to several reasons. a) The spring is immediately downward a detachment niche, dipping towards the spring, that essentially drains the water connected to the change of permeability in the bedrock. b) It is along an important fracture, that carries a part of the losses of the Renanchio Torrent. c) Finally, it is favored by the visible and buried morphology. Although it is located along a ridge, the spring occurs in a small depression between a moraine and a landslide body. It also can be favored by the likely concave trend of buried base of the landslide. At last, tracer tests of the Renanchio Torrent water with fluorescent tracer are performed, with a continuous monitoring in the Montellina Spring. The surveys permit to verify and quantify the spring and torrent hydrogeological relationship, suggesting that only a small fraction of stream losses feeds the spring.