Petroforms, also known as boulder outlines or boulder mosaics, are human-made shapes and patterns of rocks on the open ground. Petroforms in North America were originally made by Indigenous Peoples, who used various terms to describe them. Petroforms can also include a rock cairn or inukshuk, an upright monolith slab, a medicine wheel, a fire pit, a desert kite, sculpted boulders, or simply rocks lined up or stacked for various reasons. Old World petroforms include the Carnac stones and many other megalithic monuments.

Definition

Petroforms are shapes and patterns made from arranging large rocks and boulders, often over large areas of open ground, unlike the smaller petroglyphs and graphs which are inscribed on rock surfaces. They were originally made in North America by native peoples for astronomical, religious, sacred, healing, mnemonic devices, and teaching purposes. The specific names of these rock formations and the uses varied by political and religious group. Presently, some of these sites are still being used by First Nations, elders, and others.