My Geological Rock Study:A Visit to Mt. Shasta

Part IDava Bryant11/26/2011

Mt. ShastaMount Shasta is a dormant compound

stratovolcano which means it is made up of numerous phases of eruptions that formed

cones that make up the mountain today. It is also part of the Ring of Fire, a series of

volcanoes “that are distributed along the west coast” of North and South America and the East coasts of Asia. 1 It’s formation is the product of “4 relatively brief eruptive episodes” that have occurred over the past 600,000 years.2 What is most interesting about Mount Shasta are the 4

cones that make up its configuration.

Sergeants Ridge Cone is the oldest and is still visible today.

Misery Hill Cone the second oldest “grew atop the glaciated…flank of the first.”3

Shastina, the third cone is free standing about 5 miles away.

Hotlum was formed “since the retreat of large glaciers from the mountain around 6,000 years ago” and makes up a majority of Mt. Shasta’s mass.4

The following chart lists the cones and the lengths of their episodes.

Chart of Eruptive Phases of Cones5

From a more personal perspective Mt. Shasta is just beautiful. It is located about an hour North of

Redding in Northern California. My mom and grandmother live there and I make a trip to the mountain

every time I visit them. Shasta City sits below the mountain and is your

typical small town with an extraordinary view. Here are a

couple more photos.Shastina

Rocks! Rocks! Rocks!

Location of Rock Collection

My daughter, an avid rock collector (she picks them up

anywhere we go) was so excited about helping

mommy collect rocks. All of the rocks we collected were from the area depicted in the picture to the right. In

the background of the picture you can also see a few of the cones that form

Mount Shasta.

Continued in 2nd file…