Help identifying dimpled fossil (coral?)

[Emthegem]

Hello! 

 

We came across these fossils during a family trip up to Sudbury when we noticed three white boulders in front of a gas station FILLED with a variety of fossils (not sure if originally from Sudbury or not). Anyways most were rather recognizable but these ones were a little different to us:

 

Thanks in advance!

 

Also I'm not too sure what kind of rock this might be (I'm guessing limestone to start), if someone knows I would be interested!

 

-Em

[FossilDAWG]

These look very much like some stromatoporids (a kind of sponge) I have seen in Silurian rocks around Lake Temiskaming.  Rocks of similar age occur on Manitoulin Island.  They are certainly not local, as the bedrock around Sudbury is much older (Precambrian), highly metamorphosed, and mineral rich.

 

The rock is a dolomitic limestone.  You can see the sparkle of fine dolomite crystals in some of the pieces.  Much of the Silurian limestone in Ontario, Michigan, and down into Ohio and Kentucky has been altered to dolomite.

 

Don

[Emthegem]

26 minutes ago, FossilDAWG said:

These look very much like some stromatoporids (a kind of sponge) I have seen in Silurian rocks around Lake Temiskaming.  Rocks of similar age occur on Manitoulin Island.  They are certainly not local, as the bedrock around Sudbury is much older (Precambrian), highly metamorphosed, and mineral rich.

 

The rock is a dolomitic limestone.  You can see the sparkle of fine dolomite crystals in some of the pieces.  Much of the Silurian limestone in Ontario, Michigan, and down into Ohio and Kentucky has been altered to dolomite.

 

Don

Wow perfect! Very informative thanks for the ID and background info on rock type!