Please read all contents carefully.
1. Homework: Igneous processes
2. Lab 5 – Igneous rocks
ALT Igneous Rock Lab
Go to the following website: http://profharwood.x10host.com/GEOL101/Labs/Igneous/index.htm
You will find an explanation of Igneous Rocks and at the bottom, a list of sample numbers. When you
click on a sample number it will take you to a picture of a rock and a selection box to check all the
characteristics of the rock that you observe.
To earn credit for this lab you should explore ALL of the rocks and attempt to identify their
characteristics correctly. This may take a few tries.
Once you have explored the rocks please answer the following questions:
1. Which rock was the easiest for you to identify? Why do you think this is so?
2. Which rock was the most challenging for you to identify? Why do you think this is so?
3. How can you tell whether a rock cooled above ground or below ground simply by looking at it?
In other words, are there visible characteristics that provide clues to the location of its
formation?
4. What patterns did you see in the rocks? For example, igneous rocks have a range of densities,
depending on the minerals from which they are composed and their formation process and
location. Is there an observable characteristic in the rocks themselves that offers hints to this
range of density? Be specific. You may find more than one pattern to comment on. The more
the better!
5. Which igneous rock is your favorite and why?
6. Which igneous rock is still a complete mystery to you? Why?