The BMC deposits have been affected by the Salinic Orogeny  and subsequent Acadian Orogeny [23,24,25,26,27].
Metamorphism varies from lower- to upper greenschist facies with peak metamorphic conditions from 325 to 400 °C and 6 to 7 kbars .
The BMC contains 45 deposits and 95 occurrences, in which 25 deposits are more than 1 Mt, including the supergiant Brunswick No.
12, containing a pre-mining massive sulphide resource in excess of 290 Mt ( and references therein).
LA-ICP-MS developments continue to be made in terms of Pb-isotope determination [4,5,20].