Figure 4. Cutting across the metamorphic rocks from bottom center to upper right is an igneous dike of younger age than the metamorphic rocks. It is probably of Silurian age (about 420 million years old), and related to nearby intrusions of this age. The gray granitic dike includes dark blobs or enclaves of a darker igneous rock called basalt. The dike is clearly younger than the quartzite and schist metamorphic rocks and the migmatite because it cuts right across both of these units.
Last updated on October 6, 2005