Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit

Study guide for EAR 105 Test 2.

Test 2 is scheduled for Wed. Oct 25, 2023.

The test will take place in class, during normal lecture time.

If you have accommodations, those will be honored – make arrangements with ODS if you have not already.

The test will be primarily multiple choice, with some questions based on diagrams.

For this test, you will be allowed ONE PAGE, SINGLE SIDED of notes to bring with you.

This study guide is an outline of what you should be focusing on for the upcoming test. It is not a point by point outline of the test.

There is more material on this study guide than will be on the test. The points on this study guide are broad.

The points on this study guide are broad. Use those points to review and expand your notes. Use these materials to construct your study sheet.

Pay special attention to diagrams that relate to the key points on this outline.

Find the diagrams in your notes and in the textbook.

Learn the diagrams.

Be able to explain the diagrams.

Be able to identify the axes and the relationships on those diagrams.

Be able to answer questions about those diagrams.

CH 5

1) Basics of minerals

a. Definition of a mineral

b. Glasses and Amorphous Solids

c. Biomineralization (the “gray area”)

d. Mineral Identification criteria

i. Which ones are strong/most useful

ii. Which ones are less useful

iii. Which ones are unique to specific minerals (like magnetic properties, reaction to acid)

2) How minerals are grouped into classes

i. Anion as defining feature used to name mineral classes

ii. Carbonates, Halides, Oxides, Sulfides, Sulfates, Silicate, Native Elements

3) Silicates

i. Silica tetrahedron structure and implication

ii. Silicate groups

1. Ratio of silicon to oxygen

2. Independent/Isolated

3. Single and double chain

4. Sheet

5. Framework

CH 6 -- Igneous Rocks

a. Melting, the Geothermal Gradient, Volatiles, Pressure

i. Mechanisms of melting

ii. Melting location

1. Divergent settings

2. Convergent settings

3. Hotspots

b. Melt evolution and change of composition of final material

i. Partial Melting

ii. Fractional crystallization

iii. Contamination and assimilation

c. Intrusive vs extrusive igneous rocks

i. Crystal size and texture

ii. Phaneritic vs Aphanitic vs Porphyritic vs Glass

d. Types of magma

i. Mafic vs Intermediate vs felsic

ii. Bowen’s reaction series

Interlude B: Weathering and Erosion, Sediments

Physical weathering (particle size decrease)

Chemical weathering (ions removed)

Feedback between Physical and Chemical weathering

Soil development and specific soil horizons (simple version!!!)

CH 7 - Sediments and Sedimentary Rocks

a. Sediment Types, Rock Types:

i. Clastic (lithic, from rock)

ii. Biochemical (biologically derived)

iii. Chemical (deposited from water/precipitation)

iv. Organic (actual organic material, usually leaves/plants/plankton)

b. Basic processes associated with making sedimentary rocks:

c. Forming sediment à moving/settling particles à compaction/cementation à Lithification à Sedimentary rocks

d. Describing Sedimentary Rocks

i. Beds and Bedding planes, bedding plane features (ripples, etc)

ii. Strata = groups of beds

iii. Formation = many strata

e. Bedding planes, Bedding plane features (telling upstream and downstream, telling up from down

f. Unconformities, Superposition, Original Horizontality, Lateral Continuity

g. Facies concept – time equivalent depositional environments

i. changing facies boundary position over time

CH 8 Metamorphic rocks

1. Pressure, Temperature, Volatiles (H2O), and time.

2. Shape and texture change

3. Mineralogical change

4. Mechanisms

a. Recrystallization

b. Phase change

c. Neocrystallization (new minerals from old)

d. Plastic deformation

e. Pressure solution

5. In a closed system (ideal case) Chemical Composition remains the same

a. Distribution of elements changes

b. Happens in solid state, no melting

c. Protolith à Metamorphic Rock

6. Differential Stress vs Pressure

a. Normal Stress vs Shear Stress

b. Rotation

c. Compression

d. Elongation

e. Alignment

7. Foliated vs Non-foliated rocks

8. Metamorphic Grades and associated fabrics

9. Metamorphic facies (families) and associated tectonic settings

a. Pressure, Temperature, Time path

b. Metamorphic environments

i. Regional

ii. Burial

iii. Contact

iv. Subduction