Erratics are defined generally as any rock that is not native to the area which it is currently located. Mackinac Island, is made of limestone and Mackinac Breccia limestone. Which means any rock you find other then one of these two types would be considered as an erratic.
Glacial erratics were transported by glacial ice. The erratic boulders found on Mackinac Island arrived here from the north by the actions of the glaciers that covered this area over 10,000 years ago. As the ice sheet moved south it picked up rocks. Then as the ice sheets melted the rocks were deposited.
Erratic boulders can be found all over Mackinac Island. Their size and type of rock varies. What I found for you to discover is a field of erratics. They are all of the same type of rock. The ice sheet managed to keep these rocks together as it moved them south to deposit them here in a cluster.
To claim your find please email your answers to the cache's owner by clicking here. Which will open a new email with the questions in the body. Just add your answers. Be carefull walking in this area as the ground can be water logged at times. Let's not leave our foot prints here.
1.) How many erratic boulders can you count within 50 feet of the posted waypoint?
2.) In your estimate what is diameter of the largest erratic?
3.) In your estimate what is diameter of the smallest erratic?
Not required but always a pleasure to see, please post your photographs too.