Obsidian or basalt mixed with magma blocks in aquifers

Right now, the magma blocks at the bottom of aquifers feel super random when there are just a few mixed in with the stone. If they generated in larger groups and were mixed with obsidian, basalt, and/or smooth basalt, it would go a long way to make them feel less out of place. It would also be cool if this generation went down a few blocks, with a little bit of lava underneath.