The rocks on the shores of Georgian Bay give geologists clues to the earth’s turbulent childhood. When the supercontinent Rodinia was formed, the early continents South America and North America were pushed together and the Grenville mountain range rose up, 1.2 billion years ago. By 600 million years ago, weathering and erosion had worn away the Grenville Mountains. The swirling patterns in the rocks here are the deep roots of the mountains and all that is left of this ancient mountain range. The strange folds tell of rocks under great pressure, temperatures of up to 1200 degrees centigrade, and depths of up to 25 kilometers, able to flow like toffee, as one continent mated with another.