gisement de minerai

CONT: Un «gisement» de minerai est [...] une concentration locale exceptionnelle de substances qui sont ailleurs diffuses, dans l'écorce terrestre, à faible teneur.

OBS: A general term applied to rocks containing minerals of economic value in such amount that they can be profitably exploited. Also applied to deposits which, though they may not be immediately capable of profitable exploitation, may yet become so by a change in the economic circumstances that control their value.