You can't cross two different breeds and still call it a pure bred. Ameraucana and Araucana are two separate breeds, and Easter Eggers are more a 'type' than a breed. Your rooster is probably an Easter Egger, if he passes on a blue eggshell gene, otherwise, he's just a mixed breed.
Now, as...
If you don't know whether your rooster is an Ameraucana or an Araucana, he is probably an Easter Egger instead. The chicks will likely be Easter Eggers, as well.