A tale of two parks

Like California’s Yosemite National Park, the predominant rock type in Acadia National Park in Maine is granite.

Acadia is geologically older; the granites of Acadia originated in the core of ancient mountains that formed from the collision of a micro-continent with eastern North America about 450 million years ago.

But both parks experienced glaciation in the last 2 million years. In both areas, glaciers polished the granite, carved U-shaped valleys, and deposited ridges of rock, sand, and gravel called moraines. In Yosemite, these Alpine glaciers originated at high elevations and flowed down pre-existing valleys. In Acadia continental ice sheets more than a mile thick originated in Canada and slowly flowed across the entire landscape. Acadia’s glaciers are long gone, but like Yosemite its landscape continues to evolve.

For more on Acadia, click here.