Mystery Rock - Please help Identify

[MarkO]

Context - I accidentally found both of these rocks buried together (lots of details in other posts by me recently). The one on the flagstone base is not local. I am on a ridgetop (glacial kettle moraine) - that is a sedimentary rock from what I know. Please watch the videos and let me know by poll or reply whether you think these rocks "work" together or it is just a strange natural occurrence.



http://youtu.be/GNEpog_ZJRY


http://youtu.be/PfAbRkk9BIY

http://youtu.be/l2jhBEfI6Bo

[bar2kl]

Hi Mark... From what I can see, your 'mystery rock' appears to be a geofact, out of limestone, where the limestone is eroding (melting) away, exposing a harder core and leaching holes in the bottom rock where the top rock makes contact with it... I don't think the holes in the bottom rock are the product of 'wear'... I think they are points of contact between the two rocks where standing water is disolving the lower rock...JMO Pretty cool, tho.... thanks for the look...

[MarkO]

Thank you bar2kl -

You have a better imagination than I do!!!
I like that you gave it some thought and have a rationale explanation.


BTW - The hammer rock in my videos was buried beneath and to the side of the anvil -they weren't in direct contact. The anvil was oriented with the disfigured face up as it would be for pounding on (or natural erosion). The immediate surrounding area is soil - this isn't part of a gravel bed or rock pit.

Mark