If the water was there when the world was created it wouldn’t. If you removed it and then placed it there again it should
Why is this the case?
I believe the rules for basalt creation is that it forms when water suddenly hits the lava. If it was already present at creation, then that action doesn’t happen. Blockheads Geology 101.
Presumably because the water needs to be cold enough to make the basalt magma cool and harden. If water was there when the world was created it’s probably very hot.