FIELD AND MICROSTRUCTURAL ANALYSIS OF A DIKE SWARM AND A DEFORMED COMPOSITE DIKE IN THE VINALHAVEN INTRUSIVE COMPLEX, MAINE

The Vinalhaven Intrusive Complex located in Mid-Coast Maine represents a well-preserved bimodal intrusion with both granitic and gabbroic components (Mitchell and Rhodes, 1989). The intrusion was constructed through a series of successive felsic and mafic inputs over the course of 0.5 to 1.0 million years (Hawkins and Wiebe, unpublished U-Pb data, Wiebe and Hawkins, 2003). Within this wellexposed intrusive complex, detailed field and petrographic studies of a dike swarm and a deformed composite dike provide an opportunity to further refine its construction history.