This Earthcache will take you for a walk through the center of Belle Isle, a City of Detroit island park. We will be looking at some of the larger rocks left on the island by the glacier melt back. The rocks here are all native to the Michigan and Ontario, Canada, The Great Lakes basin.
Before going on our walk we will need to learn a bit about the rock formation, or rock cycle of the Michigan area.
We can start with metamorphic rock, this is the oldest type of rock in the Michigan Basin, first dates back 3.5 billion years ago during the Archean time division. Metamorphic rock was formed by pressure and heat. This rock is broken down into several categories found in Michigan, Iron Ore, Saturolite, Schist, Slate, Quartzite, Marble and Gneiss. It can be identified often by the coloring, it could be light or dark in color with opposite toned bands through the rock.
Next we will talk about igneous rock, this rock first dates back about 2.5 billion years, also during the Archean time division. Igneous rock was formed from magma, molten rock and surface lava. This rock is broken down into several categories found in Michigan, Granite, Granodiorite, Pigmatite, Basalt and Rhyolite. When identifying these rocks you will see that they have shiny flecks throughout the rock coloring. This is because of the silica that is a big part of the magma when this type of rock was formed. These rocks have many colors and textures here in Michigan; this is due to the many minerals that Michigan possesses. Many of the reds and orange tones are due to iron content, as is some of the very dark granites.
The last type we will look at is sedimentary rock, this rock is much younger than the others we talked about, it dates back about 3.5 million years ago during the late Devonian period and the Mississippian time division. Sedimentary rock was formed below the seas that once coved the area; it is made up from other rock fragment that settles on these ocean floors. This rock is broken down into several categories found in Michigan, Sandstone, Shale, Limestone, Halite and Gypsum. These types of rock come in many colors and textures including rocks that you can see smaller rocks imbedded in them.
Now that you have learned a little about Michigan rocks it is time to look at some examples of them. At the posted co-ords you will find 5 rocks, all of which are different.
Here you will see a metamorphic rock which as described above has lightly colored bands through it.
Also there are 2 rocks that are igneous rock, 1 of which is granite and the other which is Detroit River diorite. The granite has a pinkish tint to it and the Detroit River diorite is a light gray.
Then we have 2 types of sedimentary rock, 1 of which is limestone and the other which is Antrim shale. The limestone is that of a light brown or tan and the shale is black, this identifies it as Antrim.
Now that you have an idea of how to identify Michigan rocks it is time to go and take a look at what the glaciers have left behind on the island. There are 2 waymarks set for parking for those that do not want to walk the cache.
To be able to log this cache;
1. You will have to identify the rocks at each of the following locations.
2. Near the last location a picture must be taken and posted to the cache page with the Detroit river in the background.
1. N42 20.266 W082 59.165
2. N42 20.278 W082 59.149
3. N42 20.375 W082 59.187
4. N42 20.418 W082 59.216
5. N42 20.457 W082 59.358
After gathering this information e-mail them to me to be able to log and get credit for this earthcache.
This cache is set up with the permission of The Detroit Nature Zoo and the island tenants which includes the Detroit Park and Recreation.
Be sure to e-mail me within 7 days of logging the cache to get credit for your work. If the rules of finding an Earthcache and e-mailing the owner is not followed your log will be deleted without notice!
The Recreation Passport will be phased in gradually beginning February 10, 2014. Vehicles will not need the Passport during the first year of state management until their next license plate registration renewal date. For example, if the vehicle license plate registration renewal date is in March 2014, then the Passport is not needed on that vehicle to enter Belle Isle until March. If the renewal date is in November 2014, than a Recreation Passport is not needed until November. Once a full year has cycled (February 2015), all vehicles entering the park must have a Recreation Passport.
The Recreation Passport applies only to vehicles, not individuals. Pedestrians, bicyclists and those using public transportation can enter the park for free and will not need the Passport. The DNR is working with the city of Detroit to re-establish a public bus route to the island.
Annual Recreation Passport is $11.00
All caches placed at Belle Isle State Park by the Belle Isle Cachers, or Rattrak, are here with consent of the support of the DNR supervision for the island.