Aw... yer' makin' me blush. Some of the machines we used were highly specialized for each task. We had not just the native olivine to dig through, but also some various metals and other mineral rocks to contend with. We also wanted to process some of these on site to use as building materials for certain support structures and recycling systems.
So, while one "boring" machine might just grind up a material, another might actually be designed to vaporize it, distill out certain elements from the vapor, and deposit the various materials in storage containers. We used a variety of techniques including pulsed laser, a kind of ultra-sound "chisel" that cuts the same way a diamond cutter would chip carbon crystals, various explosives, and even an experimental kind of inductor that would literally cause the rock itself to heat up and go into a molten state.
While the substrate rock is certainly unique, and the tunnels give the illusion of changing on irregular levels, my alien masters I can assure you that there was no UFO that hit here.
This is the primary reason wee cobbled together our first crude nuclear reactors.
The electricity needs were enormous.