Mysterious hollow Rocks found in sandstone waterfall - Kansas

[barberman]

What in the heck are these? Under a dry waterfall in a sandstone formation we found these hollow rocks. My magnetic says they are not metallic. Located south of Lawrence, Kansas about 10 miles. Comments appreciated.

 

[Steve1236]

I'm with you on what the heck are those, they got me stumped, I'm almost thinking there made by the hand of man for some purpose and not naturally formed in nature, did they have soot in them anywhere or any signs of fire, someone on here should know hopefully, now I'm really curious if that's natural or not.

 

[blauer]

I think they are Ironstone concretions that have their insides eroded away. I find them all the time in Penna. Sometimes even still intact.

 

[barberman]

They are imbedded in the sand stone. Not placed my man but part of the rock formation. The hollow rock has a crust/shell that is almost glass in touch and breakage. I'm guessing over the last 10'000 years the waterfall has slowly eroded the rocks and ate out the softer center. It appears they have been chipped away at my others including myself. Wonder if they were originally Geodes? It would be kind of cool to break one out. However its on private land about 20 feet across a cemetery fence. So being a part of the sandstone does that make them from the glacier period?

 

[Steve1236]

Pretty cool, never seen anything like it in Arizona.