Vantage/Columbia Basin Field Trip

Transcription

1 Geology 152 Name Vantage/Columbia Basin Field Trip The primary goal of this course is to help you see the Earth from a different perspective a geological one. To accomplish this goal you will be expected to make individual observations throughout the day and answer the questions in this field trip guide from our discussions at the various stops along the route. Our stops along the route may change depending on the weather and the time of day, but we will probably go to most of the stops listed in this handout. I encourage you to take notes on this handout and then download a fresh copy from the course web site ( ) to make your final copy. It is fine with me to add photos to your final copy, but do not substitute photos for your personal explanations and thoughts. Part I: Individual Observations As we travel through the day, make observations about what you are seeing in the various regions listed below. One technique is to imagine that you are traveling with a person who cannot see the landscape. What would you tell them to accurately portray what you are seeing? The Puget Lowlands (from GRCC to just east of North Bend): The west side of the Cascade Mountains: (North Bend to the top of Snoqualmie Pass) The east side of the Cascade Mountains (from Snoqualmie Pass to around Cle Elem): 1

2 The Columbia Basin (from Cle Elum to Vantage and beyond): Part II: Observations and information from our various stops: We will stop in Cle Elum for a restroom break and for any last minute lunch purchases. Our first geological stop will be along the back road from Cle Elum to Ellensburg. This road was at one time the main highway across Washington! Stop 1: upper Yakima Valley Make some general observations at this stop. Are the layers continuous throughout the road cut? Explain. What can we tell about the history of these layers based on the characteristics of the sediment? 2

3 Stop 2: near Ellensburg What types of rocks do we find in this location? What other information might help us interpret the events that deposited the layers? Describe the type of layering at this location. We will make a restroom stop at the DOT Ryegrass Summit Rest Area. If possible we will take a few minutes to talk about the catastrophic flood history of the Columbia Basin. Record your notes below: Stop 3: near the Columbia River Describe the rocks and the fracture patterns in the rocks that we see in this location. What do these patterns tell us about the history of this area? 3

4 Stop 4: Frenchman Springs Coulee (Lunch!) Describe this area. How did the large valley (coulee) form? Explain how the climbing rock area formed. (Please do not climb on the rocks today and watch for rattlesnakes if you explore this area). Stop 5: along the entrance ramp to I-90 We will see some fine-grained sediment with pieces of black rock inside the fine grained sediment. What is the black material and how did these two materials get mixed together? Another restroom stop west of Quincy (about 20 minutes after stop 5) 4

5 Stop 6: along Lynch Coulee The rock cut exposes a layer of basalt over some other layers. Describe those layers and what they tell us about this history of this location. Stop 7: view of Columbia River and West Bar: From the vista at the top of the hill, what formed the small hills on West Bar? Describe the evidence in this general area for catastrophic floods as described by Bretz. 5

6 Stop 8: Ginkgo State Park How did the petrified trees of this region form? What information do they give us about the climate conditions in this area during the Miocene (14-16 million years ago)? What factors helped determine the present day location of the Columbia River? 6

7 Overall thoughts about the trip. What questions do you have about this area that we not answered today? 7