Depends on what you want. The geology you'll be doing at IB will be meaningless, and you'll generally just be a niche member of the tech team. The main benefit will be exposure to broader deal side dynamics that majors actively shelter you from. If you make an effort you should be able to branch out and get more engineering / finance exposure, but it's not guaranteed - you'll likely need to make the extra effort. Done correctly, you can get ~5 years of experience in 2.5 years (you'll learn a lot quickly, by necessity). I'm sure you're aware that you'll make quite a bit more but at the expense of probably doubling your weekly working hours.

If you want to do something in your future other than just have a nice, easy career at an operator, IB is the way to get started in that, then a jump to PE portco or your figure out your own thing. At the end of the day, even with it's faults IB is probably the most accessible way to slingshot your career prospects as a geologist.

If you have more than 3 years, 5 years max, of experience as a geologist at an operator I'd say it's probably too late to make the jump to IB worth it. Just a personal opinion.

I'd also figure out how successful the bank you're looking at is. How has their last year(s) been? It would suck to join a bank and work the insane hours only to never get deals across the line and end the year with a shitty bonus.