Geo 102 Lab #1

Pacific Northwest Geologic Mystery

The Scientific MethodThe basic process of the scientific method is as follows:• Observe some phenomenon or object you cannot explain.• Invent a tentative description or explanation, called a

hypothesis, that is consistent with what you have observed.

• Use the hypothesis to make predictions about future observations and actions.

• Test those predictions by experiments or further observations and modify the hypothesis in the light of your results.

• Make additional predictions based on the revised hypothesis until there are no discrepancies between theory and experiment and/or observation.

#1McMinnville

Oregon

Jökulhlaups

• Glacial outburst floods, also known as jökulhlaups, occur very rapidly and can release huge amounts of water. In Iceland, many jökulhlaups are triggered by volcanic activity beneath glacial ice.

Jökulhlaup in Iceland

Erratic - A rock fragment carried by glacial ice, or by floating ice, deposited some distance from the

outcrop from which it was derived…

- Glossary of Geology

Erratic State Park in

McMinnville

Glacial Erratics in the Willamette

ValleyMcMinnville Erratic

Icebergs near Vatnajokull, Iceland

#2Eastern

Washington

Satellite Image of Eastern Washington

The Palouse

• Ancient loess deposits in eastern Washington derived from the Columbia River and glacial outwash, blown in during the last Ice Age.

• The Palouse consists of rolling hills of very thick, fertile, soil. It known for its rich wheat production.

Loess

• Silt, sand, and dust, which are blown by wind. The source of most of the loess in the Pacific Northwest is glacial material blown from the north during the last Ice Age

Scablands

• An elevated area, underlain by flat-lying basalt flows, with a thin soil cover and sparse vegetation, and usually with deep dry channels scoured into the surface.

Scablands - Near Grand Coulee

Map of Eastern

Washington

Dry Falls and Coulee City

#3Spokane

Washington

Map of Spokane

Area

Rhythmites

Rhythmites South of Spokane

Rhythmite

• Succession of layers of sediment (silts, clays, etc.) deposited in rhythmic cycles. For example a sand layer followed by a silt layer followed by another sand layer. Varying amounts of time may separate layers.

Glacial Varves

Varve

• A pair of thin sedimentary layers formed annually by seasonal climatic changes. Usually found in glacial lake deposits, varves consist of a coarse-grained, light-colored summer layer and a finer-grained, dark-colored winter layer. Varves, and the pollen they contain, are useful for interpreting recent climatic history.

#4Coulee City Washington

Map of Eastern

Washington

Dry Falls and Coulee City

Large Boulder Near Grand Coulee Dam

#5MissoulaMontana

Detroit Dam

Detroit Reservoir in March

Shorelines above Missoula

#6Corvallis Oregon

Wallowing in a Mud Puddle

#7Camas Prairie

Montana

Camas Prairie, Montana

Camas Prairie, Montana

Ripple Marks

Camas Prairie, Montana

Camas Prairie Topographic Map

#8Dry Falls

Washington

Map of Eastern

Washington

Dry Falls and Coulee City

Aerial View of Dry Falls

Dry Falls

Shutting off Niagara

A De-watered

American Falls

1969

Eroded Gully SW of Coulee City

Labs are due two days after they are assigned by 5:00

p.m.

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