The Geology of NW waterfalls

Waterfall Geology

*cover photo*

North West waterfalls come in all shapes and sizes. They dot our maps from the ocean to the mountains creating unrivaled scenery. Diverse NW geology formed and continues to form waterfalls all across the land making the area one of the best examples of the amazing geology of waterfalls. All the waterfalls that are pictured as examples in this photo journal were shot by myself and illustrate the uniqueness, beauty, and diversity of waterfall geology in the North West

Waterfalls come in all shape and sizes, but are classified in mainly 10 styles. This is however not always the case as I was able to find more classifications from multiple sources. These are the styles that I found reoccurred in more than one source. Block, cascade, curtain, fan, horsetail, plunge, punchbowl, segmented, slide, and tiered. Below are pictures representing some of these formations.

Name: Lower Lewis Falls Type: Block

Name: Salmon Cascades Type: Cascade

Name: Soleduck Falls Style: Segmented Name: Unknown Type: Slide
Name: Twin Falls Style: Tiered

To further my research and to see geology happen before my eyes. I headed east into the Columbia River gorge, to check out Rock Creek a tributary of the Columbia River. Rock Creek made a wonderful example of changing waterfall geology and the power of erosion through rivers and their water. The Rock Creek waterfall was formed and continues to form due to high erosional force but it is interesting that other geological events are happening simultaneously. Both these geological events are seen in the pictires below. While the waterfall continues to erode soft rock, there is also major sliding going on as well. Both of these things can be seen in the photos below. Be sure to click on the waterfall creation link towards the top right of the main blog page to see how waterfalls are formed. For more information on this go to http://www.rockcreekslide.com/ and http://www.skamaniacounty.org/Public_Works/Rock%20Creek%20Slide%202007%20Presentation.pdf

Rock Creek Falls with the part of the land slide visible in the background.
The unstable geology at the top of the falls.

The lip of the falls with exposed rock and sediment visible to the left of the water. This sediment and rock looks to have been compacted together over time

About half of the slide is visible in this picture. At the top of the cliff is foundation ruminants of a house that had to be burned down so it did not slide into the canyon.

Downstream view of the rest of the slide

Eroding canyon wall with slide visible on left

This section is a fresh slide that happened while we where there!

The group in amazement after the slide occurred and happy to be safe!

During my trip I was able to identify some of the rock geology in the area which is mainly igneous rock types. Types of rocks found at the Rock Creek Slide site where Columbia River Basalt, Pumice, and Petrified Wood. Examples of those rocks are pictured below.

Rock Type: Igneous; Name: Basalt (Columbia River Basalt)

Rock Type: Igneous; Name: Pumice

Rock Type: Fossil; Name: Petrified Wood (organic material replaced by minerals)

Karen don't forget you can leave me comments by clicking "comments" at the bottom of this post. I hope you enjoyed the project.