Sunday, October 30, 2022

Shale Outcrop With Some Cool Calcite Deposits

 This was an outcrop on Hurley Mountain Road off of Dug Hill Road just west of Kingston NY.  Seems to be part of the Hamilton shale group from the middle Devonian geological period about 400 million years ago.



It seemed to be all the same kind of shale which would pretty much crumble apart if i pried at it.  

 

At one spot there seemed to be some water seeping through depositing calcite on the face of the rock. You can see in the first photo on the lower left white encrustaions on the rock face.   I do not know if this was deposited recently when the rock was exposed or how many years ago before the rock face was exposed.  Nor do I know how this rock face came to be exposed.  How do I begin to find out?  Must consult some geologists!

 



 I should have backed up and taken a photo of where these spots where.

Here are closeups of this calcite crust




did i test these tiny crystals for hardness and efferescence in acid yet?  no I have not.

Here is another kind of calcite crust on a nearby piece of rock.




dunno why my phone was on some kind of purple setting.  they were not purple.