I have seen lots of ice formations on the lake in my life but I had never seen this one until today.

I've contacted three of our local TV station meteorologists to see if they know how they formed. Will post the answers I get here later.

Here is the answer:
Many types of ice form on a lake. The first form is called "frazil ice" or "slush". These extremely small pieces of ice (2-3mm) turn into thin ice during calm conditions. "Nilas" ice is the second stage of ice formation. This is a transparent coating of ice, which, upon growing thicker, turns grey or white in color. What you are seeing is known as "pancake ice". This forms when slush accumulates into floating pads, which upon further freezing, solidify and form circular shapes. These can range up to 10 feet in diameter. You may also notice a rim on the edge of these pieces as well. This is caused by slush being splashed onto the "pancake" and freezing into ice.