Halo's Texture Style

I was just playing Halo 1, 2, and 3 on my Xbox 360 this week and I noticed that Bungie had a very interesting texturing technique. Look at this screenshot from Halo 1:
This is a 2001 game and the textures look amazing! How did they get that bump/speckled effect on those rocks? If anyone knows, please tell me.

I've played all of them (can't play halo 2 as GFW LIVE is offline), but I can't believe that Halo 1 did such a thing. Well, actually, come to think of it, Descent 3 did aswell, if you look closely at the enemies and dynamic objects. But yeah, Halo has acheived quite a good graphics score for itself, but there can be some graphical glitches...like texture mis-coordination lol, I remember when I was playing on 'The Library', it rendered a Flood with a grunt texture?!?! Wierd.

I know, I know, I may be too young for them, but I don't care. I've got Dead Space and BioShock, 2 of the scariest games, an do they scare me? Nope. Dead Space does a little bit on Impossible, but apart from that, not at all.

I'm like [MOD EDIT]NO AGE RELATED COMMENT ALLOWED NEW RULE[/MOD EDIT]
When I was 9 I played Resident Evil 2. The darn crows that burst through windows....well, after those I needed new pants.

LOL RE never scared me apart from the zombie babies X-P

Hehe, I remember the good ol' days...back when Conker's Bad Fur Day just came out... I was probably about the same age too

Back to Halo though, for the first one at least based on the screnshot, it looks like they used bump mapping, possible normal mapping. I'd say Bump because they don't seem to have the dimensions that normal maps have. Bump maps are like normal maps only grayscale to make it look bumpy. Normal maps are much better though. I don't think FPSC uses them, but I could be wrong. Bump maps were used a lot at that time...As to getting the textures to look so detailed, the probably took a picture or something and then made it seamless.

As to 'Chief, the armor definitely used normal maps, at least as of Halo 2.