Formation age

Type of rocks

Thickness (m)

Main hydraulic characteristics

General consideration


Sandstone, chalky limestone, chert nodules

40 m, elsewhere up to 100 m

Intermediate aquifer

Aquifer, with some aquiclude layers

Paleocene Eocene

Chalk marls

660 m

Medium aquifer

Maastrichtian Paleocene


695 m

Aquiclude, confining layers



Silicified limestone, phosphatic chert

Marl, dolomite, marly limestone

Around 220 m

Excellent to poor aquifer

In general, poorly developed aquifer with some good yields aquifer layers

Lower Cretaceous

Coarse, medium and coarse-grained sandstone

150 m

Good aquifer

Good to excellent aquifer