addition of some new block types?

I know Redpower adds basalt

basalt, andesite and rhyolite come to mind. If redpower is installed as a mod extrabiomes could use basalt as a place holder for that block.

region might have volcanic ash which when mixed with other materials might be made into some other type of blocks.

Place with a lot of fissures in the ground and lava streams or rivers of lava.

Hot springs, I don't think the idea has been done before in minecraft.

Maybe something similar to the effect a cauldron has with water in it? except there are pools of boiling water with lava the blocks covering the bottom of it?

Also might find a lot of dead plants nearby due to the high content of certain elements in the air.

That's all I can think of at the moment I'm sure I'll think up more and I'm sure there are others who can add to this!

While it would be nice to have new stone types available, a more robust system for recipes and their use of similar item types is needed. yeah we have ore dictionary, which is a silly name considering it's used for more than just ore, but that has it's own set of interoperability problems

as it's likely that some sort of work around or collaboration with RP2 volcanos will happen in the future I'm going to close this one until further notice.

Other types of rocks you would find in volcanic region me thinks

http://www.ehow.com/info_8043800_lava-rock-types.html

The only problem I see with a volcanic region would be that if you use Red Power...you will have to many volcanos as you can't turn them off or control how many there are. My concern is if you did this you'd have so many areas covered with volcanos and they wouldn't match. Also, the amount of basalt and marble that RP adds is quite a bit.

I could see fissures being a cool idea. Either a biome of geothermal activity or as a feature within other biomes perhaps?

I am currently working on a Hot Springs/Yellowstone looking biome document so it's good to see that someone else likes the thought of that biome too. =)

Yeah, well it would fit in with some of the forest biomes we have in in this mod. Heck I was playing the other day and made a new world with the large biome world gen and I spawned in a desert/oasis/redrock area. Looked flipping sweet and pretty accurate too seeing how those water areas in the desert were surrounded by grassy blocks. The Red Rock also blends well with desert.

As I said it's only an idea with RP2 but it could make use of the Basalt it adds, maybe at some point Elo will make it configurable for how many volcano's can be spawned shrugs

Besides that though there are a bunch of other types of volcanic rock that could be spawned.

But that aside if it doesn't pan out as a biome it could certainly well be made into a feature in certain biomes.

It would be interesting if Red Power compatibility would allow for Volcanic Regions (land and ocean) to be the only place Volcanoes are placed... or, if a Volcano exists it would indicate that a Volcanic Biome should be surrounding it.

As far as Basalt goes... EBXL could just create a Basalt and if used with Red Power then the Ore dictionary would make it able to be substituted or replaced.

I agree with that, it also makes sense.