Review for Historical Geology Common Assessment

Essential Question: How does Uniformitarianism help explain Earth's features?

Vocabulary:

Uniformitarianism

Catastrophe

Neo-Catastrophe

Concepts: Match the Geologic event to the theory on Earth’s formation:

______________ Yellowstone, Volcanic eruption A. Uniformity

______________ Formation of the grand canyon, 2 floods B. Catastrophe

& weathering and erosion

______________ Sandstone forming C. Neo-Catastrophe

Essential Questions: What is the difference between Relative age dating and Absolute age dating?

Explain whether each age description is relative or absolute. Give a reason for you answer

Middletown, PA became a town before Hummelstown, PA

Lower Dauphin High School was built in 1960.

Mrs. Fischl was born after Mrs. Cassel.

First Dinosaurs became extinct and then mammals evolved

The Earth formed 4.6 billion years ago.

Essential Question: What is relative dating, and how is it used to order past events?

1. Vocabulary

Law of Superposition

Principle of Cross Cutting

Principle of Original Horizontality

Principle of inclusions

Unconformity

Fault

Igneous

Sedimentary

Metamorphic

2. Concept: Use the diagram below to answer the following questions. Layers 1, 4, 5, and 6 are sedimentary rock; layers 2 and 3 are igneous intrusions; A is an unconformity; finally, B is a fault.

Which sedimentary rock layer is older, 1 or 6? Explain your answer and name the scientific law that you applied to reach your conclusion.

List layers 2, 4 and 5 in order from oldest to youngest.

How do layers B (Fault) and 2 (Igneous Intrusion) compare in age?

What is the boundary “A” called?

Layer 2 is an igneous intrusion. How could a geologist use layer 2 to infer the age of layer 6.

List the layers from oldest to youngest; include A & B with layers 1-6.

What does the fossil record show about how life has changed over time?

Vocabulary:

Fossil

Fossil Succession

Index Fossil

Correlation

Trace Fossil

Petrified Remains

Cast

Mold

Amber

Concepts:

1. What are fossils?

2. What conditions are necessary to insure fossilization?

3. What is the principle of fossil succession?

4. Describe how a clam might become a fossil.

5. The remains of a large animal are found in a cave along with a large pile of fossilized dung (poop). How can you incorporate this dung into your studies of this unknown animal?

6. How are the laws of superposition and the principle of fossil succession related?

Essential Question: What is absolute time and how is measured?

3. Use the diagram and explain how Carbon 14 forms and is cycled.

Use the diagram12.25, what is the the maximum and minimum ages of the sedimentary rock layers.

Layer A: Max ____________ Min__________mya

Layer B: Max ____________ Min__________mya

Layer C: Max ____________ Min__________mya

Layer D: Max ____________ Min__________mya

Layer E: Max ____________ Min__________mya

Diagram 12.25 shows layers of sedimentary rock (labeled A, B, C, D& E) as well as some igneous rocks. The igneous rocks include a lava flow which is cut by one of three dikes (igneous intrusions) and a batholith (another igneous intrusion). The absolute ages of these igneous rocks were determined through radiometric dating and give on the diagram. Check to see if the bottom layer was age dated properly.

The bottom layer was found to have 1/32 parent isotope and 31/32 daughter isotope.

How many half-lives have past?

What is the age of the sample if the half-life is 4.6 million years?

If 5 grams of parent isotope was found, how much original parent isotope was there?

Is the diagram correct? Is the bottom layer 23 million years old?

The cross section shown in figure 12.26 is from 5 different localities. Each one shows igneous rocks and layers of fossil bearing sedimentary rocks. The absolute age of the igneous rocks (found by radiometric dating) is also shown. Determine the absolute age range of each fossil at each site, and record the ages on the table.

Fossil Period Absolute AgeClam Tertiary

Gastropod Triassic

Oyster Cretaceous

Ammonite Jurassic

Scallop Mississippian

Snail Silurian

Leaf Recent

4. Describe how fossils can be used to find the relative age of a rock?

5. Describe how fossils can be used to find the absolute age of a rock?

Figure 12.26 - cross section from 5 different localities

Essential Question: How do scientists organize the major events of Earth’s past?Vocabulary:

Geologic Time Scale

Eon

Era

Period

Epoch

Evolution

Stromatolites

Extinction

Concepts: 1. How old is Earth?

2. What is the largest expansion of geologic time, covering about 88% of Earth’s history?

3. What is extinction and what caused most extinction?

4. Where do scientists believe life original formed?

5. When did Pangaea break up?

6. When did the dinosaurs exist on Earth?