G 145                           `                                                                                  

           

Objectives Cascade Mountains

 

1.  Differentiate between the High Cascades and the Western Cascade Province on the basis of age, composition, and distribution.

 

2.  Differentiate between the Plio (ancestral) High Cascades and the modern volcanic peaks.

 

3.  Describe the structure, composition, and hazards that are associated with a composite  (strato) volcano.

 

4.  Give a possible reason for the bent alignment of the N-S lineation of the High Cascade Volcanoes.

 

5.  Definitions:

      andesite                   caldera                          Cascades graben            mudflow (lahar)

      pyroclastic               intracanyon flow            platform basalts lava dam

     

6.  Describe or give the significance of the following  (see p. 147):

            Blue River Ramp

            Green Ridge, Horse Creek, and Hood River Faults

            Coberg Hills Fault

 

7.  Describe the stratigraphy of the Columbia River Gorge and discuss the reasons for the landslides on the Washington side of the river.

 

8)  Give the general composition and which episode of cascade volcanism the following formations are associated with:

      Ohanopecosch Formation                  Eagle Creek Formation                Rhododendron Formation