Geological oddnesses of the Cembra Valley
Go to the main page
The ice holes
The one I consider the weirdest natural phenomenon of the Cembra Valley is constituted by the so-called ice holes, in Cembran dialect
i busi del giac’ (or
le buse del giac’).
I report the description that Elio Antonelli gives:
«[…] These are peculiar places, where the temperature is lower than the neighbouring one. The phenomenon is evident especially in the summertime, when beyond the stagnation of the snow, inside particular holes, you can notice hoarfrost and icicles and feel gusts of cold air.
The peculiarity can be felt along the route S.P. 71, between the Lases lake and the Valle lake, with stagnation of snow and chilly air. But it's especially in Valfredda (literally “the Cold Valley”), above Lases, that you can find the more considerable sign of this naturalistic curiosity. In that valley there are natural screes and from March to November you can feel breath of cool air; till the end of July you can find inside the holes frost and icicles and the surrounding plants are of alpine type, even if the little valley is facing south-west, sheltered from the north winds and 740-760 m a.s.l. (2430-2500 ft).
The phenomenon is explained by the scholars with the presence of air channels or ways that from the high and steep zone of the scree go down, within the mass, to the base, then going out from the subsoil. In these channels, when the external air is warmer then the internal one, a draught starts, similar to a descending breeze, that conveys cold air to the lower outlet and doing out originates the cooling.
The temperature of the air that goes out is sometimes 6-10 °C (11-18 °F) lower than the surrounding one. The peculiarity is present also in the Valscura valley, at the base of the scree called Coston.»
(Storia di Lona Lases page 33 [quote translated by me]).
I could personally observe the phenomenon during a torrid afternoon of half July, while I participated to the Magnalona (gymn-gastronomic walk 
in the Municipality of Lona-Lasés). 
From the spaces among the stones of the screes and from the interstices of the containment walls it blew a fresh gentle wind.
Simply surprising: although there was definitively a summer temperature, going through the Valfredda (the name is really appropriate) I could feel a pleasant refreshment and I had the impression that to stay there a jumper would have been needed.
It seems that in the olden days, when there weren't the electrical appliances, the
busi del giac’
were used by the Cembrans as natural refrigerators for the perishable goods (and this doesn't surprise at all).
A few years ago, instead, because of the particularity of its mountain flora, the Valfredda valley has been declared a protected biotope. «[…] Everywhere there are mosses, bilberries and rare specimens of alpine and subalpine flora. The scholars have discovered not less than 144 different species. Raising some stones in the alluvial fans it's possible to find holes where hoarfrost and icicles last until late in August […]»
(Parcheggia e Cammina page 163 [quote translated by me]).
An example of a plant that you can find in the Valfredda valley is the Allosurus crispus, species typical of environments higher than 2000 m a.s.l. (6500 ft)! 
Go to the main page
The volcanic bombs
The phenomenon of the volcanic bombs can be observed in several zones of the valley. An easily accessible place is in the provincial road that goes along the left slopes (SP76), a bit below the Lases lake.
Also in this case I quote from Parcheggia e Cammina:
«[…] The peculiarity can be seen on the wall at the roadside of the provincial road, now partially covered by a metal netting. It's about circular holes in the wall that contain spherical balls of porphyry. Other «bombs» are incorporated in the volcanic tuffs, in the sandstones and in the yellow-reddish muds that can be seen a little bit northwards. The origin of this phenomenon dates back to the eruptive periods of the Permian volcanos 260 millions years ago, when the whole Porphyric Platform of the Adige river developed.
Scraps of lava were hurled in the sky with rotating motion and fell in spherical shape in the lavic mass or in the ashes, maintaining their own individuality without amalgamating with the material that received them.
Similar phenomena aren't rare and the size of the bombs varies from few centimeters to some meters of diameter (from few inches to some yards). »
(Parcheggia e Cammina page 161 [translated by me]).
«[…] Not less interesting, as they are different in their size and position, are the bombs incorporated in the porphyries nearby the Cantilaga bridge. »
(Segonzano e Sevignano page 14 [translated by me]).
Go to the main page
© 2005, Fabio Vassallo