This week marks your first opportunity to use the rock kit you purchased from the WVC Bookstore. We will also use the rocks in future weeks as we continue virtual touring of geological field sites in the Pacific Northwest.

1. Rock Questions
2. Virtual Field Site Questions

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I. Rock Questions

You have nine rocks from locations around Washington State. To view photos of examples of each of the nine rocks, open the Week 3 Lab - Rocks page.

Your job is to use the information on the Rocks and Minerals Basics page and discussion with other students in the online classroom, to identify the rocks. The names of the nine rock types in your Pacific Northwest Geology Rocks collection are as follows, in alphabetical order:

• _____ andesite
• _____ basalt
• _____ blueschist-greenschist
• _____ gneiss or schist (varies from rock kit to rock kit)
• _____ granodiorite
• _____ limestone
• _____ sandstone
• _____ argillite (slightly metamorphosed siltstone)
• _____ slate

Your assignment is to associate each sample number in your collection of Pacific Northwest Geology Rocks with its correct name on the above list. Here is one hint: The argillite (slightly metamorphosed siltstone) is fine-grained and pink or red in color.

Consult with other students as you identify your rocks. Examine each rock closely and communicate clearly about its properties. Look for texture, grain size, color and the presence of layers.

II. Virtual Field Site Questions

Tour the Newberry Volcano Virtual Field Site and answer the following questions.

10. What is obsidian, and why does it not consist of minerals?
11. Why is it not easy to realize that you are looking at a volcano when you look at a shield volcano from a distance?
12. What are the smaller hills on the side of Newberry Volcano?

Tour the Crater Lake Virtual Field Site and answer the following questions.

13. In terms of volcanoes, what is Wizard Island?
14. In terms of volcanoes, what is Mt. Mazama?
15. In terms of volcanoes, what is Llao Rock?
16. How do we know that, when the caldera of Mt. Mazama formed, felsic magma was on top of intermediate magma in the chamber beneath the volcano?
17. What do the walls of Crater Lake tell us about the volcano?

Tour the Vantage Virtual Field Site and answer the following questions.

18. What principle of relative geologic age determination leads to the conclusion that the basalt flows at Vantage have been folded or tilted?
19. Describe how pillow basalts form.
20. Explain how a forest could have existed among the basalt flows.
21. What principle of relative geologic age determination leads to the conclusion that the lakes in which diatoms flourished existed in the Vantage area after the Roza Flow of the Wanapum Basalt?

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