Plow Marks?

[CDavison]

Found this in a river and needing to know if these grooves are from plow or something else. The grooves go all the way around the rock almost perfectly.

 

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[ToddsPoint]

Ancient cracks from when that piece was part of a much larger rock. Depending on the rock, those cracks could be a billion years old. Gary

 

[Dougie Webb]

Ancient cracks from when that piece was part of a much larger rock. Depending on the rock, those cracks could be a billion years old. Gary

+1 on the above. Looks natural to me.

 

[billb]

Nice rock very old indeed and greetings from NY welcome aboard here and best of luck