(Bentonite layer in N. America- picture from great AGU blog with information about bentonite layers on the eastern side of the United States and how they are correlated to other parts of the world AGU). This could help Katherine with some of her age dating as well.
Dr. Madden lead me to a great article found in Elements, “Bentonite and Its Impact on Modern Life”. This article gave me an idea for another aspect for the bentonite that I can test when returning from the spring break trip. The article only compares sodium and calcium bentonite and the differences between them. The article exemplifies how Ca-bentonite has a lower swelling capacity and does not adsorb as much water as Na-bentonite (Elements). When I found this information I decided that if the bentonite samples we collect are rich in calcium and sodium, I could test whether it was more sodium or calcium rich based on how well the clay stays suspended in water. The calcium rich bentonite should not suspend in water well. I could used a specific amount of water and same about of clay.
Other interesting facts that the article stated were that we should find the layers of clay near areas where water was able to penetrate the layer, and therefore we should see these affects. It also stated what type of textures are present in these two types of bentonite which will help us identify them in the field.
We will further use this article to discuss the present day uses of bentonite in our final projects, such as enviromental sealents, desiccants, metal casting, drilling fluids, and cleaning agents (Elements).