The ponds that you have passed and that you see at this location are called kettle lakes. They were formed when huge chunks of ice broke away from glaciers. As they melted, the spaces that they previously occupied were left as depressions in the ground, or "kettles" that filled up with rain and snow melt. Kettles are not drained by streams, so the water that collects in them filters into the ground. Thus, Starkey’s kettles help to replenish the underlying Arkell aquifer which supplies Guelph’s water needs. Kettles also are an important surface water source and habitat for many kinds of wildlife.
Q: What is the largest kettle lake in Canada?
A: Wellington County’s Puslinch Lake.
To read more on kettle lakes, click on https://en.wikipedia.org/wiki/Kettle_%28landform%29
The Starkey Hill Interpretive Trail is jointly managed by the Guelph Hiking Trail Club and the Grand River Conservation Authority