Purple Quartzite

Purple Quartzite, originally uploaded by jw_creations.

The quartz grains that formed the original sandstone appear to have come largely from erosion of the Penokean Mountains to the north. These mountains formed about 1.85 billion years ago in the Early Proterozoic Eon, and the sandstone seems to have been laid down in the subsequent 200 million years. This was then subducted into the earth where pressure and heat transformed before after millions of years it rose to the surface as the colorful quartzite we see today.