A pebble that has arrived from the Adamello
This rock is granite. The magma has solidified slowly and the minerals present have formed large crystals.
Some crystals have altered over the time that passed between the release of the rock and its being deposited into the soil.
In these images, each of the coloured fields is a different crystal.
This granite pebble is probably tonalite originating in the Adamello area.
The tonalite contains minerals such as: quartz, plagioclase and feldspar.
The rock’s name derives from its conspicuous presence on the Tonale Pass, on the border between Val Camonica (Brescia) and Val del Sole (Trentino).
|Name:||Granodiorite or tonalite|
|Type of rock:||
Intrusive magmatic rock
|Minerals:||Quartz, biotite, hornblende, plagioclase, alkaline feldspar. Chlorite, calcite, epidote, iron oxides, sericite, titanite alteration.|
|Location:||Lazise (N 45° 30′ 39.3″ E 010° 46′ 25.6″)|
pebbles of the glacial deposits of the Sarca (morainic amphitheater of the Garda)
Pleistocene (less than a million years)
How the pebble was formed:
How the rock was formed:
on the front of a lowland glacier