Resource Dictionary

Intrusive

Refers to mineral deposits that are formed by the upward movement of magma toward the earth’s crust. The intrusive rock itself can host a large porphry type deposit (low grade, large tonnage), or important concentrations of minerals can be found around the edges where the intrusive rock has interacted with country rock. Also, because of the different mineral properties of intrusive rock, mineralization can concentrate in skarns situated to either side of the mineral “cap” or top of the deposit having “pooled” there through hydrothermal processes or leaching from the crust.