| Age | Rock types | Thickness (m) | Hydraulic properties |
| Tertiary | Chalk, marl, limestone | 490 - 530 | Detailed below |
| Wadi Shallala F. (B5) | Chalky and marly limestone | 250 | Medium aquifer |
| Rijam F. (B4) | Chalk, chert and limestone | 40 | Only locally an aquifer |
| Upper Muwaqqar F. (B3) | Chalk, marl, chalky limestone with chart nodules | 200 - 240 | Aquiclude |
| Upper Cretaceous | Calcareous sediments | 690 - 910 | Detailed below |
| Lower Muwaqqar F. (B3) + Amman F. (B2) | Silicified limestone, chart, phosphate | 30 - 120 | Excellent aquifer |
| Wadi Ghudran F. (B1) | Chalks and marls | Up to 70 | Aquiclude |
| Wadi es Sir F. (A7) | Hard massive karstified limestone | 180 | Very good aquifer |
| Shueib F. (A5, 6) | Thick marls alternating with thin bedded limestone | 50 - 100 | Aquifuge |
| Hummar F. (A4) | Hard crystalline limestone and dolomitic limestone | 60 - 120 | Excellent aquifer |
| Fuheis F. (A3) | Marls and chalks only locally limestone | 70 - 90 | Aquiclude |
| Naur F. (A1, 2) | Sandy marl, shale, dolomitic limestone | 230 | Aquiclude, except some carbonates forming medium aquifer. |
| Lower Cretaceous | Sandstones, some silts and shale, glauconite, some gypsum, dolomites and limestone | 140 | Good aquifer |
| Jurassic | Sandstone, calcareous sandstone, shale, marl, dolomite, and limestone | 130 | Medium aquifer |
| Triassic | Sandstone, siltstone, shale, marls, thin limestone and evaporates, especially gypsum | 490 | Good aquifer |