Royal Purple Lookout EarthCache

The gondola is a swiss made tram constructed in 1970. It is the steepest vertical lift for a 4 person gondola in North America. The cable is a continous loop 19,300 feet long. Wow!

Please stay on the trails. There is no need to get off them to do this earthcache. They have some very sensitive plant life that is endangered on top of the mountain so again, I state, you do not have to get off the trail. Follow the trail route to Royal Purple lookout area. If you wish to feed the squirrels, they sale squirrel food at the restaurant on top of the mountain. The squirrels will crawl right up your leg and perch on top your shoulder so be prepared. They are very friendly.

First I want to give you a little history of the geological formation of the land in this area of the country. The Columbia River Plateau was created by a series of basalt flows 6 to 17 million years ago. The flows covered 164,000 square kilometers and spread to portions of northeast Oregon, southeast Washington and western Idaho. Prior to the eruptions, there were many years of severe tectonic uplift. Rock bodies (igneous plutons) slowly crystallized below the surface and were exposed through uplift and erosion. The Wallowa Pluton has a granitic-like composition and forms the bulk of the Wallowa Mountains you can see today.

During the Pleistocene Epoch, glaciers became the most prominent landscape changing force in northeastern Oregon. The glaciers carved mountains in the Wallowa area which are referred to as the Oregon Alps. There were 9 glaciers that spanned more than 10 miles each, some as much as 20 miles. They covered the Lostine, Minam, and Imnaha. Glaciers are one of the most erosive forces on the Earth. The Wallowa’s have many glacier cut structures. Glaciers have caused the formation of alpine lakes, have shaped bedrock and formed cliff faces. As they move down valley, the carry what is called till (sediment) and it is deposited in the lower valley known as moraines.

BASIC EROSION

Erosion is the carrying away of solids such as sediment, soil, rocks and other particles. It is usually caused by wind, water, or ice by downward or down-sloped movement in response to gravity. The rate of erosion depends upon several factors. Climate includes the amount of precipitation, the temperature, as well as the wind speed and storm frequency. The geologic factors include the sediment or rock type, how porous and permeable it is, the slope of the land, and if the rocks are tilted, faulted, folded or weathered. The biological factors include ground cover from vegetation or lack of, the types of organisms inhabiting the area and how the land is used.

Depending on the ecosystem, you can expect some areas with high-intensity precipitation, more frequent rainfall, more wind, or more storms to have more erosion. Sediment that is high in sand or silt with steep slopes will erode more easily. Mass movement erosion is an important part of the erosional process as it moves material from higher elevations to lower elevation where other eroding agents such as streams and glaciers can pick them up and move it to even lower elevation. Some of this type of erosion is continuous on all slopes; some moving slow; others occurring suddenly. The sudden movement of land down a hillside is called a landslide. Slumping is when materials move downhill rapidly but happens along fracture zones. It usually creates a spoon-shaped depression. Sometimes this happens when water beneath the slope weaken it. Many times you will see this along highways as the result of poor engineering in creating the road. When the movement is at a snail pace, it is called surface creep. It is usually not noticeable by the human eye but is caused by wind along the soil surface.

WATER EROSION

Splash erosion - is the airborne movement of small soil particles caused by the impact of raindrops on soil.

Sheet erosion - is the detachment of soil particles also by raindrops. It moves downslope by water flowing overland in a sheet, not in channels. This usually happens with cloudburst traveling for short distances in a short period of time.

Gully erosion - is the result when water flows along a depression and creates a trench or gully.

Valley or stream erosion - This type of erosion deepens the valley extending it into the hillside. At first, it creates a V cross-section and the stream gradient is steep. When a base level is reached on the bottom, the erosive activity will cause lateral erosion, widening the valley. During this type of erosion, it is not only the water that erodes, but also pebbles, and boulders as they traverse the surface.

WIND EROSION

• The rougher a surface area, the less erosion. Smooth surface offers little resistence to wind.
• Speed & duration of the wind have a direct relationship to the amount of soil erosion.
• Lack of windbreaks such as trees, shrubs, residue allow the wind to move the soil.
• Loose dry bare soil is more susceptible to erosion.

ICE EROSION

Ice erosion is caused by movement of ice. Abrasion occurs when the glacier moves debris and it scrapes along the bed gouging underlying rocks just like sandpaper on wood. When glaciers freeze to the sediment and then are moved along, it carries the sediment with it. This method produced many of the lake basins across North America. This method also left moraines, kame deltas, or glacial erratic in its wake during the last glacier retreat.

From the top of the mountain when you get off the tram to the Royal Purple Lookout is only about a 5 minute easy walk. Your view from Royal Purple Lookout on Mount Howard will give you a great view of the Wallowa Mountain Range. Notice the types of erosion that have taken place in the past.

Use the educational information provided along with your powers of observation at the coordinates to answer the following questions. Please do not post your answers. Send them in an email to me.

1. Taking a picture is no longer allowed as a requirement as of 1/1/11 but would be greatly appreciated.
2. Name at least one type of erosion you see in the mountain across the valley. Did you see other evidences of erosion on your way up the tram to the top of the mountain? For extra credit, name one of them.
3. Using your gps, give me an estimate of the distance from where you are standing to the highest peak across the valley.