Department of Earth Science |Northeastern Illinois University

ESCI 121
Spring 2006

Review Sheet for Exam #2  (March 16, 2006)                                                                    Dr. Sanders

For Exam #2, you should be able to do the following:

*  Explain the relationship between cooling rate and crystal size.

*  Define and describe what is meant by the terms plutonic and volcanic as they apply to igneous rocks.

*  Define and describe what is meant by the terms intrusive and extrusive as they apply to igneous rocks.

*  Define and describe what is meant by mafic and felsic mineralogic compositions of igneous rocks.

*  Use a rock key to identify hand samples of igneous rocks.

*  Describe the three major types of material that erupt from volcanoes: 1) lava, 2) pyroclastics, and 3) gas.

* Explain how the magma composition affects the "eruptive style" of a volcano, and how this is related to plate tectonic setting.

* Explain the four factors that control melting of rocks in various settings, and say how each influences whether or not magma will be produced:
       --composition      --decompressional heating
       --temperature      --shifting of the melting curve due to introduction of water (volatiles)

* List the major types of volcanoes and explain the plate tectonic settings in which they form.

* Explain what changes take place in rocks during metamorphism as a result of increased heat and pressure.

* Define foliation and explain how it develops in rocks composed of platy minerals.

* Examining hand samples of metamorphic rocks, identify those exhibiting foliation and those that are non-foliated.

* Describe how each of the three major classes of rocks forms.

* For each of the major classes of rocks, name the sub-groups, and tell how each forms.  List the rocks that fall into each of the sub-groups.

* Explain how in the field you could recognize each of the rocks listed above.  What features do they exhibit?

* Explain the relationship between the environments of rock formation and plate tectonic setting.

* Explain how rocks of one type can be changed into rocks of another type.

* Explain the meaning of the terms epicenter and focus (also called hypocenter) of an earthquake.

* Explain the meaning of the term magnitude as it applies to earthquakes.

* Explain how we measure the magnitude of an earthquake using the Richter scale.

* Explain how we classify the intensity of an earthquake using the Mercalli scale.

* Explain the relationship between the depth and distribution of earthquake focuses (foci) and plate tectonic settings.

* Explain how a seismograph works.

* Explain what P-waves and S-waves are, and how they move through solid and liquid material in the earth.

* Explain why it is necessary to have data from at least three seismometers to pinpoint the epicenter of an earthquake.

* Using data on arrival times of P and S waves for four seismometers, locate the epicenter of an earthquake. 

Department of Earth Science | Northeastern Illinois University

© 2006 Laura L. Sanders.  Last updated March 13, 2006.