The terrain that you have just hiked across through the woods to reach the observation point for this EarthCache is the result of glacial action occurring some 10 to 11,000 years ago. Continental sized glaciers covered the entire northern regions of North America. Climate change resulted in the slow melting of the continental glacier, ultimately revealing the glacially sculpted terrain underneath. The melting ice deposited enormous amounts of debris that give the shape to the terrain, and released torrents of water that formed the rivers of Algonquin Provincial Park. The Oxtongue River on whose bank you are standing is just one of eight rivers that have their source within the park, all of which have their origin as a result of the glacial geological forces.
Today, the water of the Oxtongue River is no longer from a glacier. Melting snow in the springtime and regular rainfall throughout the year now feed the river its water. However, the sculpting of the river continues. Sometimes the erosional force of the water is severe. Large volumes of flood water tear at the banks, carry large boulders along the bottom and move enormous amounts of other debris known as bedload. At other times the water flows quietly along providing a very scenic path for canoeists and is an ecosystem rich in wildlife.
One aspect of the Oxtongue River found at this location are the rapids and is the focus of this EarthCache. Rapids in a river form when water flows over a resistant surface of rock. The sand, mud and gravel above and below the rapids are interrupted by a rock layer that is not as easily eroded. The outcome of these erosional differences along the bottom of the river is a steeper and narrower channel through which the river flows. The maze of boulders around which the water flows is the consequence softer materials from around the boulders being washed away, leaving only the rock. The river itself takes on an altered character as it "navigates" this section of the river.
In order to receive credit for finding this EarthCache please closely observe the characteristics of the river as it changes from the start of the rapids at Trail Post #7 to the bottom of the rapids near Trail Post #8 and send your answers to the questions to hiking2175@gmail.com
1. What is the approximate change of elevation of the river between the head of the rapids and the bottom of the rapids?
2. What is the approximate per cent change in the width of the river comparing the width just above the rapids with the narrowest point within the rapids?
3. How does the flow of the water and the surface of the river differ from within the rapids as compared to the water below the end of the rapids?
4. Toward the end of the rapids park officials have placed a sign warning hikers standing above the rapids. What does this sign say?
5. Optional: please upload your favorite photo taken while walking along the Oxtongue River.
Thank you for taking notice of this EarthCache on your hike of the Whiskey Rapids Trail. I hope you have had a wonderful walk and that this cache has been a rewarding part of your outing. Please do not post any answers in your log.
Congratulations to Goby who earned the "First to Find" from Canada and to Eulenschlau, the "First to Find" by an international visitor, from Hamburg, Germany. Thanks for visiting the EarthCache.