Mystery Falls
Accessing this Earthcache:
Please use the recommended parking lot (see waypoints). From there, walk east along the road to the trailhead. Follow the marked trail to the posted coordinates. This is a walk of just less than 1 km. The trails could be muddy in parts and there are some steeper slopes along the way. In winter, boot cleats are recommended. Please stay on marked trails at all times. While the property that this earthcache is on is public and open for use of the trail, adjacent properties are private and make use of animal traps that will cause significant injury to humans and pets. When you get to the posted coordinates, it is not necessary to descend to the lower creek bed. All logging requirements can be satisfied while remaining safely on high ground.
Waterfalls, while quite beautiful, are points of significant erosion of rock and soil. Niagara Falls, perhaps Canada's best known waterfall, has seen significant erosion over time with its crest receding by about 30cm per year. What you're looking at is certainly not anything as majestic as Niagara Falls.
Erosion at a waterfall occurs as water moves over the break point in the slope of a river. This point is sometimes called a nick point, and when it forms a waterfall, it is often called a crest line. As it falls over the crest, the water hits the bottom with great force and turbulence. The rate of erosion is determined by a number of factors including the volume of water, the height of the drop and the makeup of the material near the crest, behind the waterfall and at the bottom. If the material behind the waterfall is softer than the material at the crest, the waterfall will become shelf-like with an area behind the waterflow being undercut.
|
Limestone
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. It consists mainly of different crystal forms of calcium carbonate.
|
 |
|
Shale
Shale is a fine-grained sedimentary rock formed from a mud of clay and tiny fragments of other minerals including quartz and calcite.
|
 |
|
Granite
Granite is an igneous rock with a granular texture, often in shades of white, pink or grey. Granite is a very hard rock and is often found in massive, solid boulders lacking any internal cracks or other structures.
|
 |
|
Sandstone
Sandstone is a sedimentary rock composed mainly of very fine mineral particles or rock fragments. Sandstone is often found with visible bands of varying colours.
|
 |
|
Slate
Slate is a fine-grained metamorphic rock. It can often be found with parallel planes and is commonly used to create roofing shingles.
|
 |
To Log this Earthcache:
Send me an email or use the Geocaching.com Message Center to send me a message with your answers to the following questions:
- How many distinct layers of rock do you observe in the general area?
- For both waterfalls, how thick are the harder layers of rock?
- What type of material do you think the hard and soft layers made from?
- What evidence of erosion do you see?
- For both waterfalls, how far back from the leading edge of the waterfall does the erosion beneath go?
- Estimate the total drop from the crest of the first waterfall to the stream bed beneath the second waterfall.
- At the River Crossing (see waypoints), describe the makeup of the stream bed.
- (Optional) Take a photo of yourself sitting on one of the benches or with the waterfall in the background and post it with your log.
Do not include any of these answers in your log, except for the optional photo.
You may log a find at any time, but please ensure that your answers are sent to me within 48 hours. Logs without answers after this time may be deleted without notice. If you are submitting answers on behalf of a group, please include a list of account names of those who were with you to complete this earthcache.
Sources:
Landform Geology [link: slideserve.com]
This Earthcache is placed with the written permission of the
Ausable Bayfield Conservation Authority.