Every Rock Has A Story - Watersmeet Gneiss

Gneiss is a high grade metamorphic formed by the deep burial and heating of its pre-existing parent rock. This specimen of the Watersmeet Gneiss is from bedrock exposures north of the town of Watersmeet in the western UP of Michigan. It contains zircon crystals dated at 3.65 by, making it Michigan’s oldest rock and one of the oldest in the USA. Zircon crystals retain their original composition at very high temperatures thus allowing for dating of Earth’s old metamorphic rocks.