They are drilling in glacial till. Sands and gravel and clay that have been compacted by the ice to form something very similar to concrete. Although every so often the glacier will drop a huge boulder that it carried down from Canada - so not a dome of igneous rock, but it probably is a huge boulder of igneous (and very hard) rock.
Thanks. If that's the case, an uninformed person such as myself thinks all they need to do is change cutters and resume boring but I know it isn't so simple.
You know, there is only so much igneous rock in the earth.
If this is a very large chunk it would be a terrible mistake to break it up. It’s not like we can make more - it will be gone forever.
Save the igneous rock!
We need someone to chain themselves to it and then call the mainstream media.
We can use social networking to raise money!