San+Juan+Mountains+3A

The San Juan Mountains were formed in the tertiary period from thousands of km. of volcanic ash that was deposited onto the surface of the earth. The deposited ash built up to a 4200 foot set of mountains. Along with the ash that was deposited, millions of valuable rocks and minerals such as copper, lead, and zinc were hidden inside the volcanic ash which makes it a very popular spot for mining.

The San Juan Mountains are one of the beautiful places where many amazing, destructive forces are taking place. Exogenic processes shape the San Juan Mountains including freeze-thaw, mass wasting, and stream erosion. Freeze thaw is a destructive force in which water is deposited into the cracks in the San Juan Mountains. As the water begins to freeze, the rock on the outside of the crack expands, causing chunks of mountain to fall down. Mass wasting is an exogenic process in which rubble and sediment rolls down a mountain slope and builds up at the bottom. Stream erosion is an exogenic process in which sediment is washed away from the mountain with the power of water from streams. Every day, the San Juan Mountains is being weathered and eroded every day, right under our noses.

The San Juan Mountains are located in Southwestern Colorado. The San Juan Mountains are 30-40 million years old. The San Juan Mountains are rich in minerals and rocks making them a great mining destination. The San Juan Mountains are the most extensive mountain range in Colorado. The San Juan Mountain area is highly mineralized and the Colorado mineral belts figured in the gold and silver mining industry early Colorado.