LSM. a sill is an igneous (molten magma from within the earth) intrusion that enters the outer crust intruding between and parallel to existing layers. In this case, the existing layers are sedimentary, and to call them sulphidic may mean that they have sulphide minerals in them. Base metal sulphides are always a joy to find, and may be an indicator of noble metals nearby. The second dolerite sill and the sedimentary layers between them are considered prospective for gold in the companies' announcement.As the intruding magma (in this case doleritic) cools, late stage solutions bearing gold and base metals can travel outwards into the surrounding rocks,making those valuable metalic deposits that we so like our companies to find. Also the heat from intrusions can mobilise metals already in the surrounding rocks,moving them until they reach some barrier, be it temperature gradient or structural, so concentrating the metals in an ore body.
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