oredef = {clust_scarcity = moreores.silver_chunk_size * moreores.silver_chunk_size * moreores.silver_chunk_size,
            clust_num_ores = moreores.silver_ore_per_chunk,
            clust_size     = moreores.silver_chunk_size,
            height_min     = moreores.silver_min_depth,
            height_max     = moreores.silver_max_depth,