While running around Brunswick picking up a few caches and one of them took me to a really cool hike over a tributary of the Rocky River. While hiking around I could not help but notice the shale that formed the river. So I came home and started to research the history of the area and geology. The best description I could come up with actually came from an online reference, so I have attached this reference and would like to give credit to Ohio History Central at website www.ohiohistorycentral.org. Here is their reference:
During Late Devonian time, about 350 million years ago, the inland sea that stretched across Ohio and adjacent areas to the north and south, became stagnated so that the bottom waters were foul and bottom-dwelling animals could not survive. However, the upper waters of this sea were oxygenated and supported plankton and a variety of early fishes. The organic matter from the dead plankton, as well as the dead fish, settled to the bottom of the sea along with particles of clay washed in from deltas and mountains to the east, forming a thick bed of sediment that eventually would become the Ohio Shale. This tough, cliff-forming shale is dark in color and crops out in a north-south band from the Ohio River northward through the central part of the state, then eastward along portions of the Lake Erie shore. It is rich in organic hydrocarbons (kerogen) and is considered an oil shale. Large, rounded, carbonate concretions are common in some zones of the Ohio Shale. Many of the concretions contain bony plates of armored fishes.
So in order to get credit for this find here are the requirements:
From this location you will be standing on a bridge overlooking the river. I want the answer to the following questions:
1. Shale can be formed in different colors depending on the content in the rock when it forms. colors such as gray, black, greens, yellows, or reds and browns. Describe the color of the shale in this tributary.
2. Large fossil deposits are found within shale deposits, why do you think this happens?
3. Shale is a sedimentary rock, sedimentary rock is a type of rock that is formed by sedimentation of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution. Particles that form a sedimentary rock by accumulating are called sediment. Shale is mostly made up of one component, along with other minerals like quartz and calcite. What do you think is the major component of shale?
4. A pic is strickly optional, but always fun to see people out at the cache site.
Have fun and please remember to help keep our world clean.
