Plate Tectonics - Project Blog (3/26-3/30)
This is our model of the Three Sisters Mountains Summary: The three sisters mountain in Oregon were created due to the movement of tectonic plates, called subduction zones. This movement created the mountains that we know today. The oldest mountain, known as the North Sister, or "Faith" is less than 170,000 years. This mountain is most eroded of the three and contains rock pinnacles and glaciers. The Middle Sister, or “Hope,” is a stratovolcano that is made up of basalt but has also erupted less common things such as andesite, dacite, and rhyodacite. The middle sisters has last erupted approximately 50,000 years ago and is considered extinct. The South Sister, also known as “Charity,” is the youngest and tallest out of the three. It is also a stratovolcano, and is about 50,000 years old, and has last erupted about 2000 years ago. These mountains are part of the cascade volcanic are which contains many volcanoes and ranges from western North America to southwest...