Relief Map of the Pacific Northwest

GEOG102 Lab #7 3

Relief Map of the Pacific Northwest (locations are approximate)

The Hints – Questions to Ponder… Where were glaciers present 15,000 years ago?

Do not answer these questions directly in your lab report. They are hints to help you interpret what you observe at each station

1.McMinneville, Oregon

• How could a jökulhlaup (a subglacial outburst flood) have occurred in the Willamette Valley? What does the distribution of erratics in the Willamette Valley tell you about how they got there?

• What is the importance of identifying the rock type of an erratic? What does this tell you about the history of the rock?

2.Eastern Washington

• What processes (and how much force) result in rocks being stripped of soil? What processes result in rocks being submerged in sediment?

• What is the relationship between the present day Columbia River and the Scabland channels?


2 3 4 5




GEOG102 Lab #7 4

3.Spokane, Washington

• When is a puddle muddy? When is it clear? How might that result in production of rhythmites? A rhythmite consists of layers of sediment or sedimentary rock which are laid down with an obvious periodicity and regularity.

• What does the number of layers in rhythmites tell you? 4.Coulee City, Washington

• What processes can create rounded boulders like these? What natural processes can move boulders from one place on the earth to another?

• What does the rock type tell you about where these boulders came from? What does it mean if these rocks were a rock type very different than the rock near where they were found?

• What if these rocks look very similar to rocks found in Montana? 5.Missoula, Montana

• What processes create a shoreline along a lake or reservoir? • What does the presence of shorelines high on a mountainside above a valley mean? What

must have been present to create shorelines in these locations? 6.Corvallis, Oregon

• The Willamette series of soils consists of very deep, well drained soils that formed in silty glaciolacustrine deposits.

• What processes contribute to the sudden deposition of large amounts of similar-sized material?

• How is it possible that Reser Stadium has had both mammoth bones found beneath it while also having been some 400 feet underwater all within the same geologic time?

• What processes could create very flat valleys, such as the Willamette Valley? • What are some possible sources of the material that makes up Willamette Valley soils?

7.Camas Prairie, Montana

• What processes create ripples in sand? What determines how big a ripple is? • How could you get giant ripples in Montana?

8.Dry Falls, Washington

• Do waterfalls have enough energy to carry large rock or pull large rock out of the ground? Do waterfalls move over time?

• What does the size of the waterfall tell you about the size of the river? • What is the relationship between the modern river (Columbia?) and the scoured


GEOG102 Lab #7 5

The Scientific Method Einstein once said, “Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.” Use the following figures describing and illustrating the scientific method to think about the Pacific Northwest Geologic Mystery The right hand side of the figure below describing the use scientific method to study the effects of dust on mountain snowpack is a good template for the observation and interpretation section of your lab report

GEOG102 Lab #7 6

Hint Location

Observations (Just the facts)

Interpretations (What do the facts mean?)




GEOG102 Lab #7 7

Clue Location Observations (Just the facts)

Interpretations (What do the facts mean?)




GEOG102 Lab #7 8

Clue Location

Observations (Just the facts)

Interpretations (What do the facts mean?)



Additional thoughts

(if needed)