[meteorite-list] Shattercone?

[Larry Atkins]

Hello List,

I found this interesting rock close to my home in Lapeer County 
Michigan while walking in the woods this past September. It looks like 
a shatter cone to me but I've really no experience with them. One 
peculiar characteristic of the rock is that it's not smooth. All the 
rocks here have been smoothed and rounded during their glacial 
transport. I wonder if it's from Sudbury and was relatively close to 
home so it didn't have to travel very far and didn't erode too bad?
I did a few internet searches and didn't find any reference to impact 
debris being found in this area.

Any shattercone/impact experts out there?
Comments and thoughts appreciated.

http://s934.photobucket.com/albums/ad190/alienrockfarm/

Sincerely,
Larry Atkins
IMCA # 1941
Ebay username  alienrockfarm