ADVERTISEMENTS:
Some clues regarding the water bearing properties of rocks are given as follows:
(i) Permeability and non-porosity which is significant in water yielding of rocks.
(ii) Beside weathering and texture, the presence of numerous sets of joints, fractures, cleavages and faults breccias form the good water bearing zones in igneous and metamorphic rocks.
ADVERTISEMENTS:
(iii) Solution opening in limestones and dolomites may yield water.
(iv) Water may be yielded through cracks. In consolidated formations.
(v) Basalts form a good source of water.
(vi) Selection of well site in shaly region must be done carefully, recognising the storage, infiltration and seepage.
(vii) Sandstones are very good aquifers.
ADVERTISEMENTS:
(viii) Marble with fissures and cracks, heavily shattered quartzites and slates weathered gneisses and schists serve as good aquifers.
(ix) Faults generally affect the water table by blocking or diverting the flow.
(x) Synclinal trough of alternating layers of permeable and impermeable beds of rocks providing artesian conditions.
ADVERTISEMENTS:
(xi) A series of dipping formation which include a pervious or water bearing stratum with impervious beds above and below, the outcrop of the pervious bed receiving supply of water from the surface, form the artesian conditions.
(xii) The quality of water in the well depends on the various types of rocks encountered.
(xiii) Swarming of insects in evening at certain points on the surface during dry season and existence of green grass vegetation are indications of a perched or suspended water table.