Nelson's Oxbow EarthCache

The dream of Mary K. Oxley Nature Center was born at this very location of the oxbow when Philip Nelson and Dick Sherry  said "wouldn't it be great if we could get a Nature Center established here".

I'm not really sure why Bird Creek is called a creek. Its channel is wide enough to be considered a river. It begins in Osage County flowing through the hills and soon becomes a slow turgid silt filled creek. Nelson's Oxbow is not the only oxbow on this meandering creek. In fact, there are many, and both the creek and the oxbows are ever changing. When Bird Creek floods it inundates a large portion of the area. If Osage County receives heavy rain in a short amount of time the creek will rise and overflow into its oxbows. If there is more than 6 inches of rain there is a good chance that the water may spill over Mohawk Boulevard onto the nearby golf course. To add to the typical wetland scenario, the ground water also rises to the surface under the weight of the flood water in the channel and adds to the surface inundation.

The edge of the Bird Creek floodplain exposes hillsides of weathered and alternating layers of thin sandstones, shales, and Dawson coal. Bird Creek is now cutting down upon its older alluvium floodplain; remnants of its former meandering course still appear as cutoffs and old meander bends, now filled with water as ponds and lakes. The floodplain is relatively level at about 600 feet. Bird Creek drains into the Verdigris River approximately 10 miles east of this location.

A gently meandering river flows through an area of relatively flat terrain.
Water flows at different speeds as it goes around bends in a meandering river. On the outside banks of corners, the river water moves the fastest, causing lateral erosion and undercutting.
Meanwhile, on the inside banks of corners in the river, the water flows more slowly, leading to sediment settling out of the water and building up on the inside banks. This process is called deposition.
Gradually, the inside banks are filled in with accumulated deposits, and the outside bends extend further and further, forming a wide loop in the river.
The loop continues to bend further and further, until a thin strip of land called a neck is created at the beginning and the end of the meander.
Eventually, the narrow neck is cut through by either gradual erosion or during a time of flooding. (Spring flooding is commonplace in Oklahoma following torrential rains that occur when cool dry air masses from the Rockies collide with warm wet air from the Gulf of Mexico.) When this happens, a new straighter channel is created, diverting the flow of the river from the loop into the new channel.
Deposition finally seals the cut-off from the river channel, leaving a horseshoe-shaped oxbow lake. The water in the oxbow lake is no longer refreshed by the river, transforming the habitat from one supporting river life to one that is hospitable to pond life.

Criteria for logging this earth cache:

1. Take a picture of yourself with the oxbow roughly at the coordinates. The oxbow should be in the picture. If by yourself, take a photo of your GPSr with the oxbow in the background.
2. Estimate the width of the oxbow at this location
3. A fully formed oxbow lake has very little water movement. Measure the water movement by dropping a leaf in the water. If there IS movement, time how long the leaf takes to travel approximately 10 meters. Translate this calculation into meters per second.
4. Email me with the above information.

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