Introductory Geology II (GEOL 1122)

Summer Semester 2024

July 3, 2024

Review Sheet for Test 2.

Test 2 will be given virtually starting 3 pm on July 8 and ending July 10 at 11 pm. The test will comprise of 50 multiple choice exam questions. The questions are objective (as before in Test 1). This exam includes material from Chapter 18 (Glaciers), Chapter 10 (Geologic Time) and Biography of Earth (Chapter 11). The test is closed book and timed (70 minutes).

The guide below is intended to help you prepare for the exam. It is intended that the exam questions and topics covered therein will follow this guide.

Glaciers, Ice Ages.

What is a glacier and what are the three necessary factors needed to form a glacier? What is firn and how is firn formed? How long does the process take?

How fast do glaciers move? How do glaciers ablate? How do glaciers advance? Differentiate between plastic and brittle behavior. How is friction between the glacier and ground lessened so that the glacier can move laterally?

Describe process(es)forming: eskers, moraine, kettle, cirque, hanging valley, arête.

Why are U-shaped valleys formed by glaciers while V-shaped valleys are formed by streams?

How are rocks and cobbles and meteorites incorporated into glaciers? Meteorites (Antarctica)?

What are moraines? What is the significance of moraines?

What is meant by the Pleistocene Ice age? When did it take place?

What is insolation and why does it vary? What is the relation between insolation and ice ages? Milankovitch cycles (name the three components)?

How do we know there are several advances of glaciers during the Pleistocene? [Continental record? Ocean sediment record?]

In terms of longer term climate change, what is the relationship between the concentration of CO₂ and mean temperature? What are natural source(s) of CO₂? Name man-made causes of CO₂. What is meant by Greenhouse gas?

Geologic Time (Chapter 10)

Differentiate relative versus absolute geologic time. Uniformitarianism?

Be able to read the relative time of events from a cross section (Figure 10.2) and be able to apply Laws of Superposition, Cross Cutting Relations and Included Fragments to determine the relative geologic time recorded. Order the geologic events.

Define Half-life. Does the Half-live change?

What are the assumptions in measuring an absolute age (2 assumptions)?

Given P = 25, how many half-lifes have elapsed where Po = 200? How many daughter atoms are present if P = 25? (Note P is number of parent atoms. Po is the number of parent atoms before radioactive decay.) If half-life is 50 Ma, how old is this rock containing P = 25 atoms and D = X atoms?

Define the absolute age of the following: Earth, Age range of each Eon, Age of Earliest hominids. Note we will define age range of each Era in the following week and you will need to know the ages of each Era, each Eon, Age of Earth and any distinctive event discussed in class (e.g. age of hominids) for the first test.

In the Geologic Cross section below, answer the following questions applying Steno’s Laws.

Which is older: Dike D or Unconformity B? Dike D or Shale C?

Fossils/Evolution.

Life on Earth is divided into three taxa (name them).

How are these taxa differentiated (esp. Archaea from Bacteria)?

Define Evolution.

Define Natural Selection.

What is the significance of “organic soup”?

Two rates of evolution?

Biography of Earth.

Name Eons (their characteristic forms of life, characteristic rock/tectonic/mountain building events, atmosphere). Make a Table.

Mass extinctions (end Mesozoic and End Paleozoic, causes).

How did earth’s atmosphere gain in Oxygen in the Precambrian?

Transgressions, how and when? Cambrian explosion. Age of Earth?