Hydrogeology of Crystalline Rocks
Crystalline rocks include plutonic igneous rocks (granites, diorites, etc.) and metamorphic rocks (gneisses, granulites, quartzites, marbles, schists and phyllites, etc.). The plutonic igneous rocks, viz. granites, usually occur as large size intrusive bodies (plutons) while some other rocks, viz. dolerites and pegmatites, are of comparatively small size in the form of dykes and veins. The hydrogeological characters of dykes are described in Chap. 14 as they are more commonly found in volcanic rock terrains. Like other hard rocks, the crystalline rocks are characterized by negligible primary porosity and permeability. However, weathering and fracturing can impart significant secondary porosity and permeability which is highly variable.
KeywordsGroundwater Recharge Fracture Rock Radon Concentration Crystalline Rock Artificial Recharge
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