| Reading Assignment #3, and
Pre-class Exercise #3:
Introduction to Rocks
Dr. Lisa White
(Dept. of Geosciences)
This is the "preview" version of this exercise, suitable
for printing and leisurely inspection before you submit your answers to the
real thing, the interactive version on Blackboard. When you feel ready to submit
your answers, go to Blackboard's "Pre-class
Exercise" section, select the interactive version, and follow its instructions.
You should provide brief answers to the seven short-answer or "essay"
questions, worth 1 point each.
Responses are due by 2:05 p.m. Tuesday, Sept. 20. Remember that you can visit the interactive version on Blackboard as often as you like, but you can submit your answers (by clicking on the "Submit" button at the bottom of the exercise) only once. Also, if you visit the exercise, enter some answers, then leave it without clicking on the "Submit" button, Blackboard will forget the answers you've already entered and you'll have to reenter them when you return.
The questions below are based on assigned reading consisting of the following Web sites on igneous, sedimentary, and metamorphic rocks:
Description: The seven questions in this pre-class exercise are designed to familiarize you with the major types of rocks and their characteristics. Note that although you may visit the exercise as often as you like, you may submit your answers only once.
(1) Essay (short answer). What are igneous rocks and how and where do they form?
(2) Essay (short answer). Igneous rocks are classified by both texture and composition/mineralogy. What controls the texture of an igneous rock; i.e., what determines if a rock has a coarse-grained, fine-grained, or glassy texture?
(3) Essay (short answer). To classify an igneous rock, geologists need to identify the minerals in the rock. What are some ways to distinguish between the minerals common in igneous rocks?
(4) Essay (short answer). What are terrigenous (clastic) rocks and what are chemical sedimentary rocks? What are some environments where terrigenous rocks are found? What some environments where chemical sedimentary rocks are found?
(5) Essay (short answer). What does the size and shape of grains, and the range of grain sizes (that is, the degree of sorting), in a (clastic) sedimentary rock tell you about the kind of environment where the rock formed and how the rock formed?
(6) Essay (short answer). What are metamorphic rocks and in what environments do they form?
(7) Essay (short answer). Metamorphic rocks
are typically classified based on whether they have a foliated or non-foliated
texture. What determines whether a metamorphic rock acquires a foliated or non-foliated