Figure 1. Flow-banded rhyolite, a hard, black rock with thin
stripes. This photo was taken along North Haven Road north of Middle Mountain, just before the radio tower. This kind of rock extends from the road southward over Middle Mountain. Rhyolite is a volcanic rock that solidifies from a very thick, paste-like lava. As it slowly moves up the volcanic vent, the lava is stretched like taffy to produce the fine streaks and stripes.
Last updated on October 6, 2005