PROGETTO LIKE A ROLLING STONE

IL BASALTO

How is a basaltic lava formed?

The sudden decrease in pressure, when passing outside the earth's crust, causes degassing of the magma: the gases, initially dissolved in solution, undergo a sudden evaporation, separating from the magmatic melt which, consequently to the variation of the chemical composition, is transformed into lava. The gases released by the degassing process are water vapor (which generates juvenile water), CO₂, CO, SO₂, SO₃, Cl₂, N₂ and the rare elements. Basaltic lavas can, by solidifying, lead to multiple structures depending on the speed with which they cool and the characteristics of the environment. Lava has a temperature ranging from 600-1400 ° C. Although it is quite viscous, up to 100,000 times the viscosity of water depending on the composition, it can flow over large distances before cooling and solidifying, depending on its properties. When the lava solidifies, it forms effusive igneous rocks. Basalt is an effusive rock of volcanic origin, dark or black in color with a relatively low silica content. Basalt can have an appearance ranging from porphyritic to microcrystalline to glassy. In this case the basalt has a porphyric aspect. The rock has a vesicular texture: the rock contains small cavities (vesicles) generated by the gas bubbles contained in the magma. Typical of pumice and acidic effusive rocks, with more viscous lava which therefore more easily traps gases during cooling.

Roccia Dullia by Edodullia on Sketchfab

IMPIEGO NELLE COSTRUZIONI

Questa pietra lavica offre eccellenti proprietà fisico meccaniche e può essere tranquillamente utilizzata per le pavimentazioni esterne e rivestimenti, mentre per i pavimenti interni se ne consiglia la lucidatura. Il suo colore scuro trova impiego in molte costruzioni contemporanee dove vengono impiegate piastrelle e lastre in misura fissa. Il basalto può essere lavorato in superficie e tende a diventare leggermente chiaro. Le sue ottime caratteristiche di resistenza al gelo consigliano questa roccia anche in ambienti umidi e freddi. Un magnifico esempio è la pavimentazione di piazza san Pietro a Roma, ricoperta di sanpietrini, mattonelle di basalto tipiche della architettura romana sin dall’impero.