Petroform

Petroforms, also known as boulder outlines or boulder mosaics, are human-made shapes and patterns made by lining up large rocks on the open ground, often on quite level areas. Petroforms in North America were originally made by Indigenous Peoples, who used various terms to describe them.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.

Petroforms are shapes and geometrical 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 They were originally made in North America by native peoples for astronomical, religious, sacred, healing, mnemonic devices, and teaching purposes.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.

The first stone phase at Stonehenge has been dated to about 2600 BCE. Stone circles are still being made in Wales as part of the Eisteddfod movement, which incorporates this among other elements from the Druidic revival. Desert kites were used possibly by 3000 BCE; they fell out of use in the Neolithic as prey populations declined and the human population rose.

Some of the North American petroform shapes are over 2,500 years old. It is difficult to date all of them accurately because of a lack of soil deposits in some areas. Like the petroglyphs, many petroforms have complex and lengthy teachings that have been passed down orally by the Ojibway, other First Nations, and the Midewiwin. Some teachings may have been lost, along with the peoples that originally made some of the oldest petroforms in North America. In some North American states and provinces, there are laws to protect these important archaeological and historical sites. There were very few studies or specific mention of Manitoba petroform sites until the 20th century. The first detailed studies and descriptions of some sites in Manitoba were done by J. Steinbring and R. Sutton after the 1950s.

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