The Proterozoic to Cambrian carbonate rocks of the Bonnet Plume area are hosts to many lead-zinc occurrences. Some are classified as Mississippi-Valley-type deposits (MVTs) while others are thought to be veins. Six of the showings were sampled during the summer of 2000 for isotopic age dating (Pb/Pb) in order to help clarify classification and shed light on the timing of the different mineralization sources and processes.
Preliminary results show that some occurrences previously described as MVTs contain surprisingly high amounts of silver or antimony, elements usually indicative of higher temperatures than those usually associated with MVT deposits; while some evidence of stratigraphic replacement is observed in "vein" occurrences.