Extreme amount of ores

[Chandle15]

What mod or configuration is it to add such frequency and density to ores?

[BrowserXL]

You might wanna check the COFH Config for that.

[Kalbintion]

COFH core is indeed the one responsible for modifying ore generation rates. Keep in mind though that certain mods that add their own ore can still be affecting worldgen rates on its ore (tho i believe all specific ore gen configs in this pack are put onto cofh core)