Pobiti Kamani

Pobiti Kamani (Bulgarian: Побити камъни, "planted stones"[1]), tubular concretions formed around "rising methane-bearing fluid plumes", is a desert-like rock phenomenon located on the north west Varna Province border in Bulgaria.

According to the former, the formations are the result of coral activity (but detail investigation shows no coral), while the latter explains the phenomenon with the prismatic weathering and desertification of the rocks, the formation of sand and limestone concretions, or lower Eocene bubbling reefs.

[3] Based on a petrographic and stable isotope geochemical study and field observations, evidence exists that these structures represent an exceptional record of paleo-hydrocarbon seep system (low magnesium calcite cements are strongly depleted in heavy carbon isotope 13C).

The dynamic reconstruction of the origin of these structures, the processes of fluid migration and microbial mediation of hydrocarbon oxidation leading to carbonate precipitation have been studied by De Boever et al.

[4] In September 2020, Reuters reported that an image of Pobiti Kamani, photoshopped red, circulated social media under false claims that it was an "original NASA photo of Mars".