Rock Cairns are human-made stacks, mounds or piles of rocks. They take different forms, and have been built by cultures around the world for many different purposes. Cairns often serve as navigation aids helping guide the way.
Basalt is by far the most common rocks you will find on Lake Superior’s North Shore beaches. It is one of the four rock-types that make up the basement bedrock of the earth’s crust. Basically it is lava that cooled quickly on the surface. Each one has a distinctive shape and in a variety of shades of color from blush-black to grey. That quick cooling is what caused it to be dense, very fine grained (tiny crystals) and smooth – although the smooth surface is also due to glacial grinding & Gitche Gumee tossing it about for eons. That Basalt rock you hold in your hand (or wear on your body) is over a billion years old!