Tread will in no way help whatsoever in gravel, and in almost all certainty will be detrimental. Tread is only useful in sand, snow, and mud. Pavement, gravel, hard-pack dirt, grass, etc are all better with minimal to no tread. If what you're riding on doesn't leave a distinct tread pattern when you ride over it, as snow or mud would , tread doesn't help. It's a bit over a month old now, but if you haven't got a set of tires, look into Big Apples or Fat Franks for sure.
I ride my Big Apples over gravel all the time, and they do very well. Tread on gravel tends to put pressure on the edges of the gravel unevenly, which tends to cause the individual rocks to spin or twist or roll to the side as you ride over them. The rocks moving around as you ride over them is unnerving and can cause you to lose control and crash. Large, smooth, slick tires like Big Apples (when run at a lower pressure, such as 20 psi or so) deform a bit when riding over the individual rocks, and tends to not have them move underneath you as you ride.