Here's a breakdown:
* Glaciers shaped the Lower Peninsula: Glaciers played a significant role in shaping the landscape of the Lower Peninsula. During the Pleistocene Epoch, massive ice sheets covered the area. As the glaciers advanced and retreated, they carved out valleys, deposited sediment, and created the distinctive features we see today, such as the Great Lakes, the Thumb region, and the many hills and valleys.
* The underlying bedrock is older: The bedrock beneath the glacial deposits is much older than the glaciers themselves. The Lower Peninsula is primarily composed of sedimentary rocks formed millions of years ago in ancient seas and lakes.
* Glaciers were a sculptor, not a creator: The glaciers acted as a powerful sculptor, shaping the existing landscape. They didn't create the land itself, but rather reshaped it dramatically.
So, while glaciers had a profound impact on the Lower Peninsula's geography, they were not responsible for its initial formation.
