Geological History Field Trip

Geology 101 Name______

Our field trip today will be an investigation of the history of the Kent area based on sedimentary deposits along the east hill of Kent. We will hike along a pathway where portions of the hill are exposed due to the construction of the trail. These locations along the trail are like small windows into the past history of this region. We will visit four locations along the trail. At the first stop we will discuss how to collect data that will help us interpret the history. To the left is a photograph of the first stop.

Stop 1: (2 pts) How many units are found at this first stop?

Describe each unit in the space below:

1 Stop 2: (5 pts) At stop 2 gather data and record this information in the space below the photograph.

Which layer is the oldest and which is the youngest?

What relative age principle are you using to determine the relative ages of the layers?

Layer 2-1:

Layer 2-2:

Layer 2-3:

(see an additional question for this stop on the next page)

2 Layer 2-2 is mostly sand. Was this sand deposited in a sand dune or in a river? What is the evidence for your answer?

Stop 3: (5 pts) At stop three you should find a sandy layer (layer 3-1) and a finer grained layer (layer 3-2). It may be difficult to tell, but layer 3- 1 completely surrounds layer 3-2. Which of the two layers is older?

What relative age principle are you using to determine the relative ages of the layers?

What is the environment of deposition for layer 3-2? Defend your answer.

(Continue on the next page if you need additional space)

3 Stop 4: (3 pts)

This unsorted sediment could be either a glacial till from the Puget lowland ice sheet or a lahar deposit from Mt. Rainier. What types of evidence would you use to determine if it is a till or a lahar?

(2 pts) Of the four stops we made, which is the oldest and which is the youngest? What relative age principle are you using to determine the relative ages of the layers?