Department of Earth Science |Northeastern Illinois University

INTRODUCTION TO EARTH SCIENCE
ESCI 121

Section 05
Spring 2009

Daily Objectives #13 (March 3, 2009)                                                                                                           Dr. Sanders

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

w  Explain what is required of you in Homework #4.

Igneous Rocks


w  Explain how igneous rocks form, and tell in what part of the Earth they form.

w
  Explain how we can classify igneous rocks on the basis of crystal size/cooling rate, and list the three main categories within that classification scheme.

w
  Explain how we can classify igneous rocks on the basis of mineralogic composition, and list the three main categories within that classification scheme.

w
  Using the terms mafic and felsic, describe the composition of the oceanic crust, continental crust, oceanic lithosphere, and continental lithosphere.

w
  Examine hand samples of igneous rocks and tell whether they are intrusive or extrusive.

w
  Examine hand samples of igneous rocks and tell whether they are plutonic or volcanic.

w
  Examine hand samples of igneous rocks and tell whether they are mafic, intermediate, or felsic.

w
  Examine hand samples of igneous rocks and assess the rate at which they cooled: slow, fast, or virtually instantly.

w  Based on cooling rate and crystal size, tell whether an igneous rock probably cooled above ground, or below.

w
  Describe the characteristics of granite and basalt, and identify these rocks in hand sample.

Metamorphic Rocks

w  Explain how metamorphic rocks form, and tell in what part of the Earth they form.

w  Explain the difference between regional and contact metamorphism.

w  Describe the two general changes that affect rocks during metamorphism: recrystallization and foliation.

w  Explain the term protolith.

w  Explain the term color-banding and tell what rock exhibits this feature.

w  Given protoliths of clay, granite, limestone, and sandstone, describe the rocks that result after metamorphism.

w  Using hand samples of metamorphic rocks, tell which are foliated and which are non-foliated.

w  Describe the characteristics of the following rocks, and identify them in hand sample:

            schist        marble     phyllite        quartzite     gneiss

w  Examine, describe, classify, and name the metamorphic rocks in your rock kit: #101, 107, 109, 115, 116, 131, 140, 147.
 
Department of Earth Science | Northeastern Illinois University

Copyright 2009 Laura L. Sanders.  Last updated March 3, 2009.