Morasco area, Formazza, Verbano-Cusio-Ossola Province, Piedmont, Italyi

Regional Level Types
Morasco area	Area
Formazza	Commune
Verbano-Cusio-Ossola Province	Province
Piedmont	Region
Italy	- not defined -

Morasco area, Ossola Valley, Verbano-Cusio-Ossola Province, Piedmont, Italy

Morasco (Moraschg; Morast) was a summer village, located in Valle di Morasco near the confluence of Rio Nefelgiù with Rio del Gries, submerged during the construction of the homonymous artificial lake (period 1940-1954). The dam (coordinates 46°25'40" N, 8°23'46" E) of the Morasco hydroelectric reservoir is 525 m long and 55 m high.

The area surronding the Morasco artificial lake is characterised by calcschists of the Lebendun Mesozoic series with embedded layers of mica schishts, quartzite, and carbonate rocks (dolomitic marble, etc.). Typical minerals of these rocks are quartz, muscovite, carbonates (calcite, siderite, ankerite), albite, adularia, rutile (as large crystals or as acicular crystal aggregates forming mesh-like networks [var. sagenite]), dravite, pyrite and other sulfides. Other minerals, such as chlorite, aragonite, talc, graphite, kyanite, garnet, etc., are sometimes found.
Weathered calcschists are brittle and shows a brown-red colour; iron-bearing minerals (pyrite, siderite, ankerite, and ferriferous calcite) alter progressively into limonite and complete pseudomorphs and skeletal relics can be found. Muscovite sometimes alters into illite, that may appear as radiating platy spherules on muscovite crystals.

Double-terminated flattened crystals of quartz have been found in calcschit fissures to the southeast of the lake, towards the valley ascending to Corno di Ban. Kyanite is typically found in the area of Alpe Bettelmatt (Bättelmatt), to the northwest of the lake.

Fresh rocks were encountered during excavation works for the hydropower project and the Gries Pass tunnel to connetcs the Swiss Transitgas pipeline to the Italian gas network. In particular, the tunnel excavated in 1974 for the natural gas pipeline evidenced good crystals of marcasite, calcite, and ankerite in calcschists; sphalerite, stibnite, tennantite, molybdenite-3R, and talc in dolomitic marble (Graeser & Stalder, 1974; Roggiani, 1975; Mattioli, 1979).

Being a collecting area the reported coordinates are to be intended as a sort of "starting point".

Other Regions, Features and Areas containing this locality

References