Sinking in Ice

"This experiment will show you how dead plants and animals can end up frozen solid."

Fill a container half-way with water. Put in freezer until the water is frozen. Place a rock on the ice. Leave in freezer. On about two hours, check on the ice. You will see that the rock has begun to sink into the ice.

The rock is embedded into the ice. When you apply pressure to ice, it begins to melt. This is different that all other substances, which when you apply pressure they tend to turn solid. Once the rock melted the ice by it's weight, the water was pushed up around the rock and then refroze. 

This process happened over and over again, the rock digging its way into the ice.

source: Exploring Creation with General Science by Dr. Jay Wile