populate

 @Override
    public void populate(WorldInfo worldInfo, Random random, int chunkX, int chunkZ, LimitedRegion limitedRegion) {
        int X, Y , Z;
        World world = Bukkit.getWorld(worldInfo.getName());
        for (X = 0; X < 16; X++)
            for (Z = 0; Z < 16; Z++) {
                if(!limitedRegion.isInRegion(chunkX * 16, 0, chunkZ * 16))
                    return;
                for (Y = world.getMaxHeight() - 1; limitedRegion.getBlockData(X, Y, Z).getMaterial() == Material.AIR; Y--);
                logger.info("Surface at x:" + X + " y:" + Y + " z:" + Z);
                for (; Y > 0; Y--)
                    if (isOreType(limitedRegion.getBlockData(X, Y, Z).getMaterial())) {
                        logger.info("Cave block found at x:" + X + " y:" + Y + " z:" + Z + " and Type is " + limitedRegion.getBlockData(X, Y, Z).getMaterial());
                        limitedRegion.setBlockData(X, Y, Z, Bukkit.createBlockData(Material.STONE));;
                    }

            }
    }