Underground ore deposits

[Monkeelord]

For late in a game when you're spread all over the place looking for more ore, I think some scattered hidden deposits would be useful. Create high tech sensors and mines to find and harvest them. To show them onscreen have them appear with an underground overlay once found. That overlay could also help when dealing with a mess of underground belts and pipes

[Koub]

This is a very old recurrent suggestion.
viewtopic.php?f=6&t=29220
viewtopic.php?f=80&t=29236

There are some attempts in mod realm in this direction :
https://mods.factorio.com/mod/DeepMine
https://mods.factorio.com/mod/vtk-deep-core-mining
https://mods.factorio.com/mod/Noxys_Dee ... ning_Tweak
https://mods.factorio.com/mod/Prospector