The Sawtooth Mountains on Lake Superior's North Shore were formed about 1.2 billion years ago, when there was a lot of volcanic activity here. Great rivers of molten lava flowed down through huge cracks forming in the earth's crust. As the lava accumulated, jagged, gargantuan mountains were formed. Erosion then began occurring, which, over millions of years, has resulted in the lovely, striking Sawtooth Mountains of today. (Nearby Lake Superior, by the way, resulted from a sinking rift zone which dropped down & formed a massive basin as the ancient predecessors of the Sawtooths were being formed.)
No comments:
Post a Comment