What is to stop me from bringing 10 of each of those ores to the station in advance and delivering those to you during the event?

Nothing, although it may look kind of suspicious for someone to undock immediately before delivering a sample, or to deliver samples without having actually mined anything or without having stolen it from others who have been mining. In fact, I probably wouldn't take a sample from someone just coming from the station. If someone were caught cheating, of course, there would be sanctions for this particular event.

I may also vary the ore sequence and event sector occasionally.

You see that? That's Itan in first place twice in a row.

4th Corvus Mineral Research Event
Held on 5-11 at 19:00 UTC, Sedina D-14

Eight +7 ore targets met - (5,100,000 credit prize total) - Baekma Goji (+104,880 credit ore kitty)

Also present:

Darkwing Duck
iry
Mr. Chaos
Niki
Optimates Centurion

Thanks to all who participated!

Next weekend there will be no Corvus Mineral Research.