See YS p.252 regarding maneuvers/aspects; your spells look OK, but to place an Aspect on a scene needs three shifts, plus whatever else you want to add. Take a look at the example of Evan Montrose's winds spell. Your "Gravock" spell is illegal, unfortunately. It's trying to be BOTH an Attack AND a Maneuver. However, if you inflict consequences (as an Attack) on the target (always a happy thing), it may well indeed put the Aspect "Prone" on him.
Far better to have a spell for attack ("I do six shifts gravity damage!") and perhaps another rote to either block or place a maneuver ("I keep him from moving with a gravity well spell, six shifts as a block on his Athletics, resisted by his Athletics skill."). At least that's how I think it's done.
Either as a maneuver or as a block the bad guy still gets to resist. It all depends on what Aspect you're trying to place on him.