SCIENCE

Midterm EXAM 2: Study guide

The exam will be organized according to the following:

· Multiple Choice questions (40 %)

· Short answer questions (20%):

· Lab exercises and rock identification (30%):

· Rock identification: Sedimentary Rocks (10 %) (include comprehensive questions about rock properties, rock textures, etc.)

· Geologic time absolute and relative dating 20 %)

· Essay Questions (10%): It will request discussion of certain Earth processes.

· Go again over the reading guides posted on Blackboard and put them together with your notes from class. Make your own list of key words for each subject. You can use the list that is in the book at the end of each chapter. Eliminate words that were not discussed in class.

· Look at diagrams, tables and pictures that are in your textbook and in the notes on Bb that explain geologic processes (like sedimentary structures and environments, etc.).

Maria’s advice: Practice with rock samples several times prior to the exam

List of essential things to know:

WEATHERING and SOILS (Chapter 5)

· What are the two main categories of weathering? In what ways are they different?

· Mechanical or physical weathering: explain how water, salt crystal growth and biological activity can cause mechanical weathering. Give examples of each.

· Chemical weathering: dissolution (limestones by acid rain), hydrolysis and oxidation : Be able to explain each process and give an example.

· How does climate affect weathering?

· What is soil? Why is soil an interface in the Earth System?

· List and explain the five basic controls of soil formation.

· Examples of soil erosion: The Dust Ball

SEDIMENTARY ROCKS (Chapter 6)

· What is a sedimentary rock?

· Describe the ways in which loose sediment converts into hard sedimentary rock (lithification)

· Contrast the basic groups of sedimentary rocks: Detrital (or clastic) and Chemical/biogenic

· What are sedimentary structures ? Why are these structures useful to geologist?

· Mud cracks, cross bed, dunes and ripples, what are they and what do they reveal about past environments. (Also check in class handout)

· Explain why sedimentary rocks are important in the study of Earth history and their economic importance: which energy resources are associated with sedimentary rocks? What resources are in Michigan?

METAMORPHISM and METAMORPHIC ROCKS: (CHAPTER 7)

· What is Metamorphism? Describe the main changes that occur during metamorphism (mineral and texture changes)

· In which three geologic settings is metamorphism most likely to occur?

· What are the agents of metamorphism?

· What are the two textural divisions of metamorphic rocks and the conditions associated with each occurrence? Describe the textural differences exhibited by metamorphic rocks (foliated, non-foliated).

· What are the different types of metamorphism?

GEOLOGIC TIME (CHAPTER 18):

· Describe absolute and relative age of a geologic event: distinguish between numerical ages and relative ages

· List and describe the principles or rules used for relative dating:

· Principle of Superposition

· Principle of Original Horizontality

· Principle of Cross-cutting Relationships

· Principle of inclusions

· What is the significance of an unconformity?

· Describe and identify the different unconformities (gaps in the rock record): Angular Unconformity, Nonconformity and Disconformity.

· Explain how is determined the absolute age of a rock: What are isotopes? What is Half Life?

· Exercises from handouts: know how to calculate the absolute age of a rock

Resources:

· Textbook and reading guides

· Mastering geology homeworks

· Lecture quizzes

· The videos below are a good complement of lectures, especially if you missed class:

· weathering and soils (weathering 0-13 min) (soils: 14 – 27min)

· sedimentary rocks (sedimentary rocks formation 1- 10:40 min) (sedimentary structures:10:40-25 min)

· metamorphic rocks ( 30 sec – 16 min)

· geologic time (relative age: 50 sec – 17 min) ( absolute ages: 17 min – 25 min)