Moat Mountain Mineral Site Trailhead

The Moat Mountain Mineral Site is located on the contact zone of two rock units:  the Conway granite and Moat volcanics.  The Moat volcanics are large deposits of volcanic debris that were ejected from the Earth by ancient volcanoes nearly 200 million years ago.  Conway granite crystalized from a magma beneath the Earth’s surface after the eruptions that formed the Moat volcanics.  As the magma of the Conway granite rose against the overlying Moat volcanics, fluids were trapped as bubbles within the magma.  The magma solidified and crystals had the space to grow within the fluid bubbles frozen in the rock.  Today, crystal-bearing bubbles in granite (known as miarolitic cavities or pockets) are common in the Conway granite at its contacts with the Moat volcanics.