Fletcher Loop Valley
Hello Class!
Introduction
The above picture is a shot of Fletcher Loop Valley. . .Or, at least the Right Side of Fletcher Loop Valley! Most of my research was done on the Left Side of the Valley. There are several large cliffs with exposed rock layers there that I found incredibly useful for my research.
Location Information
Fletcher Loop Valley is located roughly 2 miles outside of the town of Okanogan. In order to reach it, you take the B&O road up past the Garbage Dump and turn off onto Spring Coulee Road. From there you take the next right onto Fletcher Loop Road. After this you need an ATV vehicle to get back to the location. It is located roughly 1 mile from Fletcher Noop Rd. to the West. Here is a rough map, however, it does not quite show the exact location.
Geological History
This particular valley was formed by glacier ice sheets that covered most of the Okanogan Highlands during the Pleistocene Epoch. When this ice sheet retreated it left many large areas that later, due to ice melt on the glacier, became lakes. Between these too major factors, and wind/rain erosion, this valley became what it is today.
There is no evidence of any types of basalt flows in this valley, as it is far enough away from the Sanpoil Volcanoes that any lava flow would not have reached it.
Basic Rock Types
This is a far away view of the rock walls that i did my research on back in Fletcher Loop Valley.
This is a close up example of the rock walls in this valley. It is mostly made up of metamorphic and sedimentary rock. The main types of metamorphic rock I found were granite mixed with feldspar (much like the rock above).
This is an example of some quartzite that I found in the area as well. The grains in this quartzite range from medium to large in size. It is a very hard rock and it took a lot of work in order to break some off of a boulder in the area.
The stratigraphy pretty much goes like this. (From oldest to Youngest)
Granite
Quartzite
Shale
Sediments
Summary
My research was very difficult due to the fact that there is no published information on this area (I looked. . .hard. . .) However, I did enjoy examining the rocks in the area and trying to figure out what went into the formation of this area. I could not completely identify what eras all of the rocks were formed in, so my stratigraphy is more just a list of what I figure to be the oldest layers through the youngest layers. I enjoyed doing the research, and I also enjoyed this class and learning how to identify rock formation and different types of activities (such as unconformities, basalt flows, etc,.) that go into making the formations that we see just about everywhere we go.
Later this summer I will be taking a trip down to Texas (through Utah, Nevada, Arizona, New Mexico) and it will be incredibly interesting to be able to identify the different formations and the rock types that are in them.
Email: audreymfletcher@hotmail.com
