Basin

Basin, a term commonly used in geology for a region in which the rocks are folded into a centro-clinal, all dipping downwards towards a central depression, or into a synclinal in which they dip towards a line of depression. Our British coal-fields owe their preservation to such folds affecting the coal-measures, and such underlying rocks as the millstone grit, carboniferous limestone and old red sandstone, and artesian wells (q.v.) are rendered possible by similar folds, as in the Artois. London, Paris, Southampton, and Vienna basins.