The Crystal River is a small drainage river formed when the glaciers moved out of Canada and cut the Great Lakes during the Pleistocene Epoch, some 12,000 years ago. The Crystal is capable of supporting a vast range of wild life, from otters to great blue herons.
Below: a picture of a perch I caught while fly-fishing. This proves that the glacial runoff in the stream is healthy enough to support fish. such as this perch.
The river is a familiar location and always busy with canoes and kayaks. The cold water can be inviting on warm summer days. During the fall, salmon run up the stream to spawn in Crystal Lake.
If you take a look at the substrate of the river (bottom), you will see that it is made up of mostly alluvial and glacier deposits. The bottom of the river was deposited during the Wisconsin Glacier. As the glacier moved along, it picked up various sediments and deposited them here when it melted.
If you look closely at the bottom of the river, you may find a curious little rock grey drab in color. When wet, it reveals a smooth pattern of radial hexagons packed together. This is a Petosky Stone, and is actually a fossil, a colonial coral called Hexagonaria percarinata. This animal lived in a warm, shallow sea about 450 million years ago during the Devonian Period.
So, if the coral lived in a warm shallow sea, but the Crystal was formed by glacial melt-off, how in the world did these things get here?
Science may have an explanation- after the Petoskies were fossilized and deposited, the Wisconsin Glacier formed the Great Lakes and its melt-off formed the Crystal River. The alluvial sediment mixed with the sedimentary rock. The current and abrasive actions of the current polished and cleaned the Petoskies into what we see today.
TO LOG THIS EARTH CACHE AS A FIND, YOU MUST:
(OPTIONAL)
-Take a picture of you and your GPSr (or just your GPS) in front of the canoe portage.
(MANDATORY)
AND TO DEMONSTRATE THE EDUCATIONAL VALUE OF THIS CACHE, YOU MUST E-MAIL ME THE ANSWERS TO THE FOLLOWING QUESTIONS VIA MY PROFILE:
1. About how long ago was the Crystal River formed?
2. What makes up the substrate we see today?
3. During which geological period were Petosky Stones formed?
4. Using your data from the previous questions, infer and draw a conclusion and state in YOUR OPINION as to the time gap between the Petoskies and the Glacial Alluvium. Several variables may play a role in your decision, including depth in the substrate, color, deposit altitude, etc. Good luck and happy hunting!
BELOW-pictures I took while snorkeling in the Crystal River. They didn't turn out as well as I had hoped.
A shoal of Largemouth Bass:
