ABSTRACT
The composition of rocks and soils has a direct bearing on the quality of water. Hydrochemically a rough classification into three rock groups. seems practical:
• Rocks in which fresh groundwater is common, that is, rocks that contribute extremely small amounts of salts to the water
• Carbonate rocks that contribute dissolved matter but maintain good potable quality
• Rocks that enrich the water with significant amounts of dissolved salts, often making them nonpotable
The lithological parameter is only one of several parameters that control groundwater quality. Other factors include evaporation at the surface prior to infiltration, transpiration, wash-down of sea spray, and reducing conditions in the aquifer, connected to H2S production. Water moves underground, and its salt or mineral content is determined by all soil and rock types it passes through. Thus, occasionally, saline water may be encountered in rocks that by themselves do not contribute soluble salts.
