Department of Earth Science |Northeastern Illinois University

ESCI 121
Spring 2007

Daily Objectives #11
(February 21, 2007)                                                                        Dr. Sanders

By the end of today’s class, you should be able to do the following:

Igneous Minerals, Igneous Rocks

* Review:  Explain the relationship between cooling rate and crystal size in an igneous rock.

* Review:  Explain the difference between rock and minerals of a mafic (basaltic) composition and felsic (granitic) composition, and tell
how to recognize each type in a hand sample.

* Review:  Sketch a "melting curve" on a graph with axes showing temperature and pressure.  Show on which sides of the curve liquids and solids would exist. 

* Review:  On the graph, sketch another curve, for a rock material that melts at a higher temperature.  Label the two curves to show which one illustrates  melting of silica-rich material, and which one illustrates melting of silica-poor material.

* Finish viewing the Discovery Channel Raging Planet series film, "Volcano!"

* Describe the three main shapes/profiles of volcanoes, and explain why they are different and how it determines their eruptive style.

* Describe and explain the connections between a volcano's location and plate tectonic setting, types of tectonic plates involved, mineralogic composition of the magma (felsic, mafic, intermediate), volcano shape/profile (cinder cone/dome, composite cone/stratovolcano, shield), volcano eruptive style, silica content of the magma, melting temperature of the rock material (higher/lower), and the material erupted from the volcano (e.g. gas, pyroclastics, lava).

Department of Earth Science | Northeastern Illinois University

© 2007 Laura L. Sanders.  Last updated February 21, 2007.