A few examples of what Mr. Osmanagic would probably call "artifacts...

"Mud-cracks"

Southwestern Virginia, USA

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Lac du Salagou, Hérault, France

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St. George, Utah, USA

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Klingenthal, Vosges, France

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Newfoundland, Canada

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"Flute casts", "groove marks", "tool marks" and "load casts"

Load cast, Cheshmehanarak, Iran

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Flute cast, Nord-Est Iran

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Flute cast, Kadkan, Iran

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Flute cast, Tafilalt, Maroc

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Groove mark, Surenenpass, Suisse

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Groove mark, Rudawka Rymanowska, Pologne

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Tool mark, Liscomb Island, Canada

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Flute casts, Gaspe Peninsula, Quebec, Canada

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Flute casts, Gaspe Peninsula, Quebec, Canada

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Flute casts, Salton Trough, southern California

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"Molds", imprints from concretions or crystals

Nova Scotia, Canada

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Empreinte de cristaux dans du grès, France

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Jaizkibel, pays basque, Espagne

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