Formation age

Thickness (m)

Type of rocks

Main hydraulic characteristics

General consideration

Lower Cretaceous

70 - 150

Mainly coarse grained sandstone with some clay lenses

One aquifer

One major interconnected sandstone and siltstone aquifer containing fresh water

Ordovician

820 - 970

Coarse, medium and fine-grained sandstone with some silt and conglomerate.

One inter-connected aquifer

Cambrian

380 - 400

Precambrian

0 - 150

Semi-consolidated alluvium and colluvium

Granitic basement

Mainly granite

Aquifuge