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Geological Features Tour

Introduction and Welcome
Welcome to Geological Adventures, where we bring you to the science. We are delighted that you are interested in finding out more about the geology of our planet. Geology is more fun as you experience it first hand. Learning about the geology of our planet will help make clear the reasons why we should do all we can to protect it. On this tour we will be visiting both the east
and the west coasts of the continental United States. On our tour we will learn about many geological features, including volcanoes, ground water and caverns, and natural rock formations found on the coast.
Mount Shasta, California
Our first stop will take us to beautiful Northern California about 60 miles from the California-Oregon border and in the southern part of the Cascade Range. The Cascade Range has 15 main volcanoes of which Mount Shasta is the second highest with an elevation of 14,162 feet.
Mount Shasta is a composite type of volcano consisting of alternating layers of pyroclastic fragments, or explosively erupted volcanic rock, and solidified lava flows. Mount Shasta was built, as was other composite volcanoes, over enormous spans of time. Mount Shasta is believed to be more than 300,000 years old. Eruptions from composite volcanoes are intermittent with hundreds or thousands of years between eruptions. Mount Shasta last erupted in 1786. Even though Mount Shasta erupted more than 220 years ago it is still considered an active volcano.
As an active volcano, Mount Shasta has many things to explore and learn about. About 300,000 to 360,000 years ago the entire north side collapsed, creating an enormous landslide. Since that time Mount Shasta has been building. Mount Shasta has four distinct and overlapping cones waiting to be explored.
The Sargents Ridge cone is the oldest visible cone and extends southward from the peak of Mount Shasta. Dozens of lava flows and fragmental layers have worked to form this large cone some...