Posted: December 2nd, 2014

Rock and Mineral Test

Rock and Mineral Test

Please provide thorough answers to each question.  Many questions have multiple parts, so be sure to answer each part.  The last question refers to the graph given on

the last page.  Either print the graph, complete it, and scan it back in to the document that you submit, or print the graph and turn in a paper copy on Monday.

Please submit a digital file (doc or docx) via canvas by Monday, December 8, at 10:30 a.m.  The point value of each question is given in parenthesis.
(18)  1.  What are the six most common minerals (or mineral groups) in sedimentary rocks?  List each, give an example of each, and discuss why they are commonly found

in sedimentary rocks.  (Ch. 6 of your text may be helpful).
(12) 2.  Why are the rocks of the Andes Mountains in South America predominantly andesite?  Why is it not the plutonic equivalent, diorite?  Name and describe the

specific process and geologic setting that supports the formation of andesite in this region.  Provide a thorough discussion.
(12) 3.  In the Cascade Mountains in western Oregon, one can find rocks of varying composition yet they formed from a single batholiths (large pluton) cooling

intrusively. Explain how the process of magma differentiation can create rocks of varying composition within one magma chamber.
(15) 4.  Why is shale the best parent material (vs. limestone or sandstone for example) for recording differences in metamorphic grade? List the following rocks from

lowest to highest grade: gneiss, slate, garnet-staurolite schist, mica schist, phyllite, kyanite schist, migmatite, and chlorite schist. Make reference to index

minerals in your discussion.
(6) 5.  List and describe the three main agents driving metamorphism.  In your discussion, include how each influences the physical and chemical properties of

metamorphic rocks.
(6) 6.  Using the QFL diagram for sandstone classification, classify the following rocks (you MUST show your math!):
1.      Cement: Quartz, 10%
Q: 90/90
F: 0/90
L: 0/90
Classification: ________________________________

2.      Cement:  Quartz, 10%
Q:  15/90
F:  50/90
L:  25/90
Classification:________________________________

3.      Cement:  Calcite, 10%
Q:  30/90
F:  0/90
L:  60/90
Accessory mineral: Mica
Classification: _______________________________
(6) 7.  Suppose the chemical analysis of an igneous rock sample has the following weight percentages:
SiO2:     54%
FeO:    8.2 %
MgO:    4.75%
CaO:    8.75%
Na2O:    3.3%
K20:    0.75%
Appropriately label the axes and plot this chemical analysis on the graph given below.  Using the following percent distributions of SiO2, this igneous rock is

classified as  ____.
Percentage SiO2        Name of Extrusive Rock
<52                Basalt
52-57                Basaltic Andesite
57-63                Andesite
63-70                Dacite (fine equivalent of grano-diorite)
>70                Rhyolite

PLACE THIS ORDER OR A SIMILAR ORDER WITH US TODAY AND GET AN AMAZING DISCOUNT 🙂