Geodude can be found in Route 114's breakable rocks, Granite Cave, and Shoal Cave. Graveler can only be found in Shoal Cave.
Hoenn is not kind to Geodude, as ORAS strips it of more available places to catch it. This means that in that small pool available locations, Geodude is not the most common and there are simply much better Pokemon to catch there as your first encounter.
The boosts that followed from Gen IV keep Geodude up to speed, ironically. Sturdy is now a very good ability, allowing Geodude to check threats that once OHKO'd it easily. The physical/special split relieves Geodude of types that it couldn't handle directly, specifically Dragon and Dark. The Eviolite breathes new life for Graveler, if the player cannot evolve it for any kind of reason. ORAS compared to XY, also updated learnsets so that Pokemon learned moves much earlier than before, and Geodude has been blessed with that.
In a nutshell, Hoenn is still not a friendly place for water weaknesses. However, Geodude isn't going to fully sink this time.
DexNav and Horde Battles allow the use of Sand Veil (HA) Geodude, but it is inferior to Sturdy.
Gym #2 - Brawly (Dewford Town, Fighting-type): Yes Geodude can survive with Sturdy, but its attacks won't do as much back.
Rival (Route 110): Geodude should only fight Slugma, the rest will all kill it before it can create a dent.
Wally (Mauville City): Sturdy Geodude can take a Magical Leaf, and OHKO with a high Magnitude.
Gym #3 - Wattson (Mauville City, Electric-type): Geodude sweeps with Magnitude, though should watch itself against Magneton's Magnet Bomb.
Tabitha/Shelly (Meteor Falls, tag battle with rival): Tabitha's Mightyena is the only one with Intimidate, while Shelly's has Quick Feet making the battle in Sapphire more easier. Either way, Mightyena can only annoy you as it has no attacking moves at all. Numel is easily downed with Magnitude, but Carvanah may be an issue with Aqua Jet. Koffing and Grimer are blasts from the past... of Johto, and should be handled with Rock STAB and Ground STAB respectively. Be sure to watch Geodude's HP in this fight, as well as its stats.
Tabitha/Shelly (Mt. Chimney): Same as the last fight, just remove the annoying Mightyena. So, it's actually easier then?
Maxie/Archie (Mt. Chimney): For some reason, the Mightyena in Sapphire once again does not have Intimidate, making that fight easier. In Ruby, Graveler should be sent out later, leaving Mightyena for someone else to handle first. Golbat goes down to Rock STAB. Camerupt is an actual threat, as it has Earth Power. Though Sturdy helps negate, and Graveler can hopefully launch a high Magnitude attack. Sharpedo is less threatening, as while Ice Fang is super effective and off a high attack, Graveler still has the higher defense to tank it, and throw back a high Magnitude as well. (Watch out for Rough Skin.)
Gym #4 - Flannery (Lavaridge Town, Fire-type): Slugma and Numel are easily handled with Magnitude. After the first Overheat, Torkoal will gradually get worse. Though it is best for Graveler/Golem to kill it quickly with Magnitude as well.
Gym #5 - Norman (Petalburg City, Normal-type): Faint Attack is no longer a threat, neither is Retaliate. Power Up Punch is the best move here, racking up on the first Slaking to sweep the other two Pokemon.
Courtney/Matt (Southern Island, tag battle with Steven): Courtney's Camerupt will OHKO Graveler/Golem with Earth Power, or leave it in range for Koffing to kill. Not to mention, this specific Camerupt has Solid Rock, an ability that weakens Super Effective attacks meaning Magnitude will be nerfed. In Ruby, this battle is best left to someone else, preferably a Water type. In Sapphire however, Ice Fang will only 3HKO. This gives Geodude and Metang (Steven) some time to kill Sharpedo first. Be sure to watch out for Grimer too, who can also be hit by Magnitude.
Tabitha/Shelly (Weather Institute): Against Tabitha, Camerupt can once again OHKO with Earth Power. Solid Rock prevents even the highest Magnitude from scoring an OHKO, so Graveler/Golem will have to PP stall Earth Power out by spamming healing items. Against Shelly, Sharpedo is much easier to deal with.
Rival (Route 119): Slugma is still the only safe kill.
Gym #6 - Winona (Fortree City, Flying-type): Swellow is easy pickings, but Pelipper and Skarmory can hurt Graveler/Golem a lot. Altaria won't OHKO with Earthquake, giving Graveler/Golem a chance to hurt it back. However, Dragon Breath is a risk to hold. The best and safest thing Graveler/Golem can do here, is set up Stealth Rocks. Another risky strategy is the Rock Polish one, but Winona's last three all have good bulk.
Courtney/Matt (Mt. Pyre): Same as the last battle against a sole Camerupt and Sharpedo.
Rival (Lilycove City): Swellow is a new safe kill for Graveler/Golem, alongside Magcargo.
Courtney/Matt (Lilycove Hideout): Rejoice! Camerupt no longer has Earth Power! And Graveler/Golem likely has Earthquake now, give it hell! Sharpedo hasn't changed at all.
Gym #7 - Tate and Liza (Mossdeep City, Psychic-type): "Come play with us Graveler/Golem, forever and ever and ever-" Yeah, don't.
Maxie/Archie (Seafloor Cavern): Somehow, both Leader's Mightyena do not have Intimidate. Mightyena and Crobat are easy pickings. Weezing on Maxie's side, can Explode but Graveler/Golem is prepared to take it at full health. Muk on Archie's side goes down easily to Earthquake. Mega Camerupt still doesn't have Earth Power but rather resisted moves, and thus dies easily to a Earthquake as it loses Solid Rock upon Mega Evolving. Sharpedo is now, the more dangerous once. As it Mega Evolves, Strong Jaw + Crunch can OHKO under a critical hit. Graveler/Golem can 2HKO with Earthquake, but it may not be enough. If necessary, Graveler/Golem should use Power Up Punch on one of Archie's previous Pokemon to get an attack boost to put Sharpedo in for good.
Primal Groudon (Cave of Origin, Omega Ruby only): Precipice Blades is a direct OHKO on Graveler/Golem, and it takes at least 3 Earthquake attacks to kill Primal Groudon. The math is not in Graveler/Golem's favor.
Primal Kyogre (Cave of Origin, Alpha Sapphire only): In the Cave of Origins, the trainer gets into swim gear as they prepare to follow Primal Kyogre down underwater into the deepest cavern to fight it. Those are all signs that Graveler/Golem should stay out of this fight.
Gym #8 - Wallace (Sootopolis City, Water-type): Graveler/Golem will get OHKO'd by Luvdisc.
Wally (Victory Road): Altaria can hurt a lot with Dragon Pulse, though Stone Edge can rid it easily if Graveler/Golem survives. Delcatty is handled fairly easy, but watch out for Charm and Sing. Roselia's only Grass attack is apparently a physical one, but it will still OHKO Graveler/Golem so stay away. Magneton has Flash Cannon and Sturdy, guaranteeing it a chance to survive. Graveler/Golem should let someone else handle this one, if it is already weakened. Mega Gallade is not a fight Graveler/Golem wants to do alone, but it could bait it into using Close Combat on it at full health to activate Sturdy, so that another teammate can come in to take advantage of Close Combat's negative side-effects.
Elite Four Sidney (Ever Grande City, Dark-type): A good strategy to take advantage of here is giving Graveler/Golem a Persim Berry, negating Swagger and gaining the attack boost back. If Graveler/Golem wants to stay in, it should set up with Rock Polish and Power Up Punch on Mightyena. From there, it can sweep Cacturne and Shiftry easily. Make sure Graveler/Golem is at full health against Sharpedo, to insure Aqua Jet does not OHKO it. Absol is frail and handled easily under the sweep conditions. Otherwise, Graveler/Golem should stay out of this fight.
Elite Four Phoebe (Ever Grande City, Ghost-type): Dusclops will halt Graveler/Golem's sweep efforts if it uses Curse, forcing it to switch out before it's too late. Power Up Punch cannot hit any of Phoebe's team, so it is best for Graveler/Golem to take out the frailer Ghost types (Banette, Sableye) rather than waste time trying to get momentum going.
Elite Four Glacia (Ever Grande City, Ice-type): While her team is a bit, 'dehydrated' since RSE, Ice is still not a type Graveler/Golem wants to walk into. Although if any of them sans Walrein is giving the team trouble, a full health Golem can switch into to someone, and launch Heavy Slam right off the bat. Just be sure that Hail is not set up prior.
Elite Four Drake (Ever Grande City, Dragon-type): Graveler/Golem can take either Dragon Pulse or Moonblast from Altaria and live, to launch a Stone Edge though it should hope for a crit or put it in the healing range. Both Flygon resist Graveler/Golem's STABs, and should be avoided. Kingdra should be avoided for obvious reasons. Salamence despite Intimidate, is all physical so Graveler/Golem has a chance here. Dragon Rush 2HKOs, and so does Stone Edge on Salamence with Intimidate, so it's all up to a critical hit or healing stall.
Champion Steven (Ever Grande City, Steel-type): Skarmory can hurt with Steel Wing, but not in a lethal way. Stealth Rock should be set up, and then Graveler/Golem switched out. Claydol resists everything Graveler/Golem throws at it, so it should avoid that. Aggron has Sturdy, so it will survive a OHKO Earthquake. However, Graveler/Golem take Iron Tail as a 2HKO. Golem has a chance to outspeed Cradily, who is otherwise extremely dangerous with Giga Drain. Golem under Stealth Rock, can OHKO Cradily with Heavy Slam. The same can be said for Armaldo. Mega Metagross however, is deadly and Golem can only hope to attempt to fight it at full health so that it survives Tough Claws + Meteor Mash. Earthquake at the same level, manages a 2HKO even with Stealth Rock. Graveler/Golem will need a lot of external help for this to work.
Post-Game: If Graveler/Golem handled Drake with care, Zinnia will require the same kind of effort.
From its earliest encounter, Geodude starts with: Tackle, Defense Curl, Mud Sport, Rock Polish, and Rollout (level 11) which replaces Tackle. Defense and Rollout work well in conjunction, but Geodude may not have time to set up. Mud Sport is a waste of a slot as Geodude would rather kill Electric types itself. Rock Polish is a neat trick to boost Geodude's speed, and cover one of its biggest weaknesses. Magnitude is at level 15, and is Geodude's main yet unpredictable way of handling Electric types. Rock Throw is at level 18, but is inferior to Rock Tomb as a TM from Roxanne. The same can be said for Rock Blast at level 22, should it only hit twice and should Geodude want the speed drop. Smack Down at level 25, is out classed by the fact that Rock STAB does more than enough on Flying types. At this point, Geodude will have evolved into Graveler. Stealth Rock is available at level 30, a very good supporting move to affect entire teams. Earthquake is worth the wait at level 40, and should replace Magnitude. Explosion isn't worth it at level 44. If the ability Geodude has is Rock Head, Double-Edge at level 50 is worth a try. Stone Edge at level 54 is the final move and, one of the best Rock STAB Graveler/Golem gets.
Golem has two secret moves that its pre-evos don't get, Steamroller and Heavy Slam. Steamroller is good against Grass, Psychic, and Dark. Which is, actually more utility than Brick Break. Though it is very low power compared to most of Golem's stronger attacks. It is only good for the flinch chance. Heavy Slam is very good as Golem is one of the heaviest non-legendary Pokemon, thus taking advantage of its high base power.
TM wise, Stone-Edge can be earned just in Lilycove City and is an much earlier way of getting the move. Sandstorm is a good fit for the Sand Veil variants, but that's pretty much it. Brick Break vs. Power-Up Punch is based on preference, but both are solid fighting moves. Keep in mind that Power Up Punch is available much earlier in Mauville City than Sootopolis City. Rock Tomb is much better than Rock Throw especially with the speed drop, meaning Graveler/Golem can ditch it on the go as the player already gets it from Roxanne. Rock Slide is stronger than Rock Tomb but has 5 less accuracy, it also has a flinch chance that a normal Graveler/Golem can't utilize as it is really slow. Though a Rock Polish set can try to abuse it.
Physical: Stone Edge, Earthquake, Power-Up Punch / Stealth Rock, Heavy Slam / Double-Edge
Speedy: Rock Polish, Rock Slide / Rock Tomb, Steamroller / Heavy Slam, Earthquake
Minimum stats are calculated with 0 EVs, IVs of 0, and a hindering nature, if applicable.
Maximum stats are calculated with 252 EVs, IVs of 31, and a helpful nature, if applicable.
Geodude Line Ratings
What Nature do I want? If you want to take advantage of Rock Polish, then Jolly is the best way to go. Otherwise, Brave or Adamant are also good to use.
Which Ability do I want? Sturdy is hands down, the best ability. It allows Geodude to survive just a little bit where it would have actually died.
At what point in the game should I be evolved? You should have Graveler by about the point between Wattson and Flannery, and Golem can be achieved anytime should you have access to trade evolutions.
How good is the Geodude line in a Nuzlocke? Geodude is a solid Pokemon for any Nuzlocke, but it shines the best in the early-game. After the midway point, it begins to falter and struggle. Hoenn accelerates this a bit, as the region does no favors to Pokemon weak to Water or Ground. In ORAS, the Geodude line is found in fewer places and mostly in breakable rocks. This means that for the main part of the route, there are simply better and more worthwhile Pokemon to find as your first encounter easily. There are also much better Pokemon to use as either a Rock or Ground type, such as Aggron and Camerupt.
Weaknesses: Ground, Steel, Ice, Fighting, Grass (x4), Water (x4)
Resistances: Flying, Normal, Fire, Rock, Poison (x0.25)