5.2G| Exercise: Identifying Common Igneous Rocks

Instructions

Now you'll apply what you learned about igneous rock textures and compositions to naming common igneous rocks. You'll use your textbook's Classification of Igneous Rocks table. If you are unable to access the document, reach out to me right away.  

To use the table, first determine the texture of the rock and composition of the rock. Second, find the texture on the chart, e.g., Phaneritic. Third, find the composition on the chart, e.g., Felsic. Fourth, match those two characteristics up, and you have your answer, Granite.  

In your lab textbook, refer to section 5.3 and Figure 5.7.

Read each question and choose the best answer. You have two attempts and no time limit. 

Note: If you find that you need extra support in accessing any items in this quiz, please notify me via email right away so I can offer you an alternative.

Time Needed

10-15 minutes.

Learning Objectives

• Students can explain the rock cycle, differentiate among the three types of rocks, and use texture and composition to identify common rocks and their origins
• Describe the processes that form common igneous rocks
• Use texture to classify igneous rocks and to interpret their cooling history and origin
• Describe how the ratio between Fe/Mg and silica dictates the color and composition of igneous rock
• Describe how and where magma forms and evolves 
• Identify intrusive igneous features