My Ore Gen Class
public class OreGen implements IWorldGenerator
{
@Override
public void generate(Random random, int chunkX, int chunkZ, World world,
IChunkProvider chunkGenerator, IChunkProvider chunkProvider) {
/* runs 'generateNether' or 'generateSurface' depending on which dimension you're loading */
switch(world.provider.dimensionId) {
case -1: generateNether(world, random, chunkX*16, chunkZ*16);
break;
case 0: generateSurface(world, random, chunkX*16, chunkZ*16);
break;
}
}

public void generateNether(World world, Random random, int x, int z) {}

public void generateSurface(World world, Random random, int x, int z)
{
this.addOreSpawn(MEBlocks.ORES, world, random, x, z, 16, 16, 50, 20, 0, 256);
}

public void addOreSpawn(Block block, World world, Random random, int blockXPos, int blockZPos, int maxX, int maxZ, int maxVeinSize, int chancesToSpawn, int minY, int maxY ){
for(int i = 0; i < chancesToSpawn; i++){
int posX = blockXPos + random.nextInt(maxX);
int posY = minY + random.nextInt(maxY -minY);
int posZ = blockZPos + random.nextInt(maxZ);
new WorldGenMinable(block, maxVeinSize).generate(world, random, posX, posY, posZ);
}
}
}