Delwar’s Earth
Studies class
GEOS 100
Fall 2003
Exam 1 Review for Exam # 1 on
Reference Text: Earth - An
Introduction to Physical Geology, Tarbuck and Lutgens, 7th Edition, Prentice Hall
Notes
to remember: The exam
will contain about 55 to 65 questions. There may be some bonus questions. On
the exam day, you will be given an ID (a combination of
three numbers that will be written on the right hand corner of your exam)
that will be used for the rest of the semester for the purpose of posting exam
grades. You have to write that number somewhere safe and use that onwards for
other exams too where you have to write ‘Social Security Number’.
Chapter 1: An Introduction to Geology
Nature of Scientific Inquiry: What is a
hypothesis, model? What is a theory? When a theory becomes law?
Scientific Methods: Steps – 1. Gathering facts, 2. Development of model
that adequately explains the facts, 3. Design of
experiments, and 4. Finally analyze the results and accept, reject or
modify the model.
Rock
Cycle: Study figure 1.12 to get idea of the rock
cycle. What are the factors that
influence formation of a particular rock type? For example, igneous rock
forms as a result of cooling and solidification of magma. Weathering (physical
breakdown and chemical degradation), transportation (by rain, wind, glaciers)
and deposition (in a lake, ocean or in any kind of depression/basin) and later
cementation and compaction (collectively we can call solidification) of earlier
formed rock fragments make sedimentary rocks. Heat and pressure causes
physical and chemical changes in the rocks and converts earlier formed rocks
into metamorphic rocks (metamorphism=transformation).
Chapter 2: Matter and Minerals
What is a mineral? Remember the five points!
How does the elements combine to form minerals?
Read the ‘Octet Rule’, study figures 2.5
(ionic bonding), 2.7 (covalent bonding). What is metallic bonding.
Polymorphism of a mineral (diamond=graphite, calcite=aragonite).
Physical Properties of Minerals: form
(figures 2.8, 2.10, 2.11, 2.16), luster, color (figure 2.25), streak (keep in
mind the cherry red streak of hematite, and black streak of magnetite from your
lab class), hardness (go through Mohs hardness scale,
remember hardness of simple stuffs used in the lab, e.g., glass plate 5.5,
copper penny 3, finger nail 2.5), cleavage (figures 2.8, 2.9, 2.10, 2.12,
2.13), fracture (figure 2.14), specific gravity (what is it?), special
properties.
Silicate structure: single chain, double
chain, sheet structure (study figures 2.18, 2.19, 2.21). Try to relate cleavage
with silicate structures from figure 2.19. For example, olivine has single
tetrahedrons. As a result it is grainy in appearance with pyramidal (top right
corner of figure 2.8) crystals. Micas have sheet like structure, as a result
you can peel of individual sheets from a big piece of mica (figure 2.12).
Quartz has three dimensional crystal network as a
result it is very strong and durable and has fracture (figures 2.11B, 2.14)
Gemstones: Why graphite is not a gemstone
whereas diamond is? Why the gemstones are more valuable than other stones? What
makes them different
Chapter 3: Igneous Rocks
Magma and lava, are they same? If not what
is missing in what? Know the various types
of igneous rocks. What are the factors that
controls/influences the formation of igneous rocks (pp. 66)? Texture
(appearance) – what can be interpreted from an igneous rock texture (pp. 66 –
69) ? How cool the rock looks like ?
Study figures 3.2, 3.3 (aphanitic, phaneritic, porphyritic and
glassy), 3.4 (vesicular), 3.6 (pyroclastic) for
various textures. For pegmatitic texture read
Mineralogy of common
igneous rocks (study figure 3.7 and 3.8). How the rocks are named (see figure 3.8, 3.9, 3.11, 3.12, 3.13, 3.14,
3.15) ?
Bowen’s Reaction series (see figure 3.23).
Difference between continuous and discontinous
reaction series! Study the figure (3.23) to find out information about certain
groups of minerals which are stable at a certain temperature range and found in
certain type of igneous rocks (we did that in the class!). Alteration or change
of composition of magma: What is magmatic
differentiation, assimilation, and magma mixing?
Chapter 4: Volcanoes and Other Igneous Activity
Read the history of eruption of
Know the structures of 1. Shield Volcano, 2.
Composite Cone, and 3. Cinder Cone. What makes them
different? Size or type of eruption or location.
Know dikes, sills, laccoliths, batholiths.
What type of features are these? Plutonic or volcanic?
And associated rock types. Think about it. (HINT:
coarse grained - slow
cooling; fine grained – fast cooling, glassy – rapid cooling)
Where can you expect volcanic activity in
terms of pate boundaries? Convergent, divergent or transform?
What is a superplume?
What type of volcanic activity is associated with that?
Chapter 5: Weathering and Soils
Types of external processes: Weathering,
Mass Wasting, and Erosion.
Weathering process types, factors that
controls weathering activity. Know the
differences between various physical and chemical weathering processes (For
example: frost wedging – thermal expansion, oxidation - dissolution – hydrolysis).
Know the relation of weathering sequence to
Bowen’s Reaction series (Study Figure 5.14 from text). Why is that?
What are the factors controlling weathering
rates? How rock type, climate affects weathering?
What is soil? How soils develop? Constituents
of soil (Figure 5.16) and types of soils (residual, transported). Know the differences
between residual and transported soils. Where the soils would develop better
and faster – residual or transported? Think about it!
What are the controls of soil formation? Know
how the factors influence the soil forming process.
What is an ideal soil profile? Know the
order of horizons (like O, A, E, B, study Figure 5.19). What are the criteria’s
for this zonation? Know topsoil and subsoil.
Know soil types and their related properties
(pedalfer, pedocal, laterite, hardpan). Remember the
slides for soil erosion and know relative importance of water and wind.
Any questions: Send email to delwar.ahmed@wmich.edu
PS: The figures listed in this
review are not exhaustive. There may be additional figures that have been
referred to in the lecture text. The figures listed here are the most relevant
ones, but it is recommended to go through the additional figures (may not be
listed here) too!