What is this rock with lots of holes?
The rock is a limestone or fine-grained mudstone but the holes are modern - made by sponges, annelids and bivalves (Piddocks) which bored into the rock very recently. There are also some barnacles attached to an exposed Piddock crypt:
Where did you find this rock?
I found it by the Ottawa River in Ottawa Canada.
Can you say exactly - that's a long river. Your rock has been colonised in marine salinity so it must have come from a sea coast.
At Deschene Rapids Lookout off Sir John A. Macdonald Parkway W.
That's a long way from the sea...
