This is an earthcache and will require you to visit the location, find a specific item and make observations to be able to answer the questions that make up the logging requirements. There is no physical container at this spot, but you will find something far more interesting.
Logging requirements
1. Please send your answers to either my email or the " Message the owner" tab Either will work.
2. If you are in a group, only one member needs to submit the answers however each person will need to post a photo showing they were on site. A group shot is acceptable. Please do not post spoiler photos.
Questions
At the posted coordinates you will find a number of large sedimentary stones, the largest of which is approximately 5 ft long x 3 ft wide and stands just over a foot in height. Look at the fossils found in this stone as well as some of the other large stones and find an example of a solitary rugose coral. Some examples are posted as spoiler photos on the cache page.
- Mandatory: send a photo of the fossil you find and say whether it is showing the horn shaped side view of the coral, or the circular cross section of the horn.
- What is the length and width of the fossil you found?
- In a one foot by one foot section on any of the larger rocks, count and tell me the number of rugose corals you spot?
- From the cache page write up: a) what geological period saw the creation of rugosa coral? b) do they still exist or are they extinct?
- What is a common name for solitary rugose corals?
- What is the name of the Michigan state stone and what type of rugosa coral does it belong, solitary rugosa or colonial rugosa?
- Mandatory: Each person in group needs to upload a photo showing they were at the a cache location. Group photos are acceptable. No spoiler photos please
Ordovician Period and Ordovician radiation
The Ordovician geological period, one of six periods during the Paleozoic Era, and spanned over 41.6 million years from the end of the Cambrian Period to the start of the Silurian Period, ending approximately 443.8 million years ago.
During this geological period, there was an intense diversification of marine animal life, sometimes called the Ordovician radiation. It was during the Ordovician radiation period that Rugose corals, large cephalopods, brachiopods, trilobites, gastropods, cystoids, jawless fish are among some of the animals and corals that evolved and thrived in the seas that dominated much of the earth.
Diorama showing examples of solitary rugosa corals (Horn coral)
Rugose Corals (Rugosa)
Rugose Corals, sometimes called horn corals due to their horn like shape , can be found in fossilized sedimentary stone along the shores of Lake Michigan. They are an extinct group of Anthozoa that included Scleractinia, Rugosa, Tabulata and Octocorallia. These corals went extinct at the end of the Permian period.
There were two types of rugose corals, solitary and colonial.
Solitary rugosans include Caninia, Lophophyllidium, Streptelasma and Neozaphrentis
Side view showing horn shape, and cross side view showing circular shape
Colonial rugosans include Hexagonaria and Prismatophyllum with a similar appearance. Their corallites were shaped like hexagonal prisms. The Michigan state stone, the Petoskey stone is an example of the Hexagonaria rugosan fossil.
Hexagonal prism shape of colonal rugosa coral
