HYDROGEOLOGICAL MAP OF LESSINI MOUNTAINS ... - CC-WaterS

CARTA IDROGEOLOGICA DEI MONTI LESSINI - HYDROGEOLOGICAL MAP OF LESSINI MOUNTAINS
Figure 22: A quarry near Camposilvano, with Oolite di S. Vigilio (below) and Rosso Ammonitico (above)
Stratigraphically overlying jurassic terms are the Biancone and Scaglia Rossa formations, lower
and upper Cretaceous in age, respectively. They consist of thickly-stratified fine-grained limestones,
whose global thickness ranges from about 200 m in the western sector to over 400 m in the eastern
sector. They come in the form of wide strips, scarcely steep along the slopes and rounded ridges at
the top of the medium-high Lessini Mountains.
The top member of the Biancone, which corresponds to the Cenomanian (fig. 29), plays a
significant role for its important hydrogeological implications: they are thickly-stratified marly
limestones and bituminous marls, whose thickness ranges from 50 to 80 m in the area of the Lessini
Mountains. In particular, the passage to the Turonian is marked by 65–130 cm of black and yellow
argillites and siltites. This formation is intensely fractured in the Lessini Mountains due to the
presence of many faults, and plays a considerably important role from a hydrogeological point of
view (see section 5).
Subsequently, during the Paleogene, basalt-like volcanic rock was laid in the Alpone-Agno graben
which took the form of small-grain, often stratified, breccias. The same magmatic cycle also
includes dyke bodies and eruption vents of breccia (necks), which intruded into sedimentary
formations all over the area of the Lessini Mountains (fig. 23).
Units of the Eocene (Scaglia Cinerea, Calcari Nummulitici and Marne di Priabona) crop out along
ridge tops and, in the case of Calcari Nummulitici, originate a marked karst morphology with
scattered groups of dolines. Eocene limestone are also found in the grabens of the area of Bosco
Chiesanuova.
Finally, the most recent terms of stratigraphic succession are found in the vicinity of Verona,
represented by calcarenites and sandstone from the mid Miocene.
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