sentences:  At least five porphyry and transitional vein-type mineral occurrences were deposited during this period.A series of smaller intrusions were emplaced during the second magmatic stage 2.2 to 3.9 million years ago, at least some of which appear to have been feeders for the overlying volcanic pile.The Franklin Glacier Complex is substantially older than the neighbouring Silverthrone Caldera to the northwest.