I guess this is a major design issue in most infinite maps randomly generated.
When there is an update, like there just was with 0.13.0 and new deposits and more abundant gold deposits, the chunks generated prior to the update do not get updated with the new parameters.
The list of the generated chunks is already in the game files.
Maybe there could be a system where the game flags chunks that were modified by a player (deposit harvested, structure placed...). After each update, or maybe only after an update that modifies terrain, the game regenerates all chunks except the ones flagged.
Of course we don't want to have massive difference between two adjacent chunks, like a sudden cliff, or a snow biome into a sand desert biome, but chunks can be generated according to their neighbours.
(i had to travel 45 chunks = 720 blocks to find an aluminium deposit :)
Or better yet - if there arent any buildings in a 6-tile radius, generate some ores there from time to time, something like mc1
Have a fantastic day!
~cakedon (formerly itsLiseczeq)