question on this rock

[love2velo]

Breccia with unusual Clasts

Found this puppy (aka beast) on the shores of Lake Michigan. Appears to be a huge conglomerate / breccia, I noticed that the light clasts have some swirling in them and when I sanded one down (1st pic), it almost looks like Oolite (4th pic is same clast)

Could anyone chime in with thoughts on how would something like this formed? Hydrothermal Breccia maybe? What about the first pic? Never seen quartz like this (assuming it is quartz)

 

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[digger460]

Can't help identify, but cool specimen

 

[alan p]

Nice cool rock, I would spend a lot of time looking at that, top and bottom pics look a little but like quartz 2nd pic look like banding of some sort but 3rd pic (the cool one) look like it has a crust on top and 4th pic look like the crust on a meteorite, looks like a mars or moon rock but not sure about the banding, whatever it is its a cool rock, nice find

 

[love2velo]

Here are a few more showing the banding. I agree with quartz or quartite perhaps but the detail in first pic has me stump. Hoping someone knowledgable can help. It definitely has a lot going on - 25lb beast as a reference

 

[Eu_citzen]

Right. So here's for starters an example of a hydrothermal breccia - quartz glues the rhyolite fragments together.


On your first pic, I'd say chalcedony. It can get some funky patterns,.

#2, with the banding could be quartz related to. Brecciated Quartzite?

 

[love2velo]

I sanded some of the darker section (1st pic) and it appears to be breccia too......Really curious how this formed - could this be an impact breccia?