volcanic splash

Chose a point that you can see and a ball of volcanic lava shoots toward the chosen point (at a speed of 100 mph's) that acts as a 100 pound boulder once it reaches the point. Once the lava hits the ground a wave of lava rushes over in a area of 10 feet dealing 3d12 fire damage and 3d12 force damage pushing each target hit by this 20 feet back taking another 1d12 force damage if they hit a wall. Then a puff of volcanic ash rises over the landing site in a sphere with a radius of 120 feet. This last for the duration and well the spell lasts any creature that starts their turn or moves through the ash takes 6d6 and this area is coincided difficult terrain.