It (bizarrely, I know) occasionally really breaks the immersion for me that there aren't different rock strata. Again: I realize this makes me a crazy person.
I agree. Volcanoes would need to be obviously volcanoes. Much as earthquake faults would need to be clearly visible. (though there are cases where earthquakes happen on previously undiscovered faults, but this could be restricted to higher difficulty levels)
Peaceful and possible Easy wouldn't have disasters at all, or the random number generation would be 3 digits instead of 2.
I just don't see this being fun at all though. Even if it was limited to certain areas on certain difficulties, I don't see what kind of challenge this adds to the game. Just a random annoyance that would lock down certain areas.
If you want environment-based dangers, add in hyper and hypothermia, and mix up mobs throughout biomes. Something that can actively be fought.
This is a great idea, I would personally appreciate more depth (no pun intended) to MINE of Minecraft. I like this idea of "If I see this block type, I'm likely to find these other block types nearby" (method, pattern, logic!) instead of the current random tunneling and oh look here's a little pocket of something.
IMO, having geological features to look for and go by makes Minecraft less tedious (and encourages surface exploration) than just randomly digging just anywhere knowing the map is evenly laced with small nuggets of resources differentiated only by vertical layers. After all, real mining involves digging in places where you are fairly certain something is deposited in significant quantities, but right now (praise be to Notch and so forth) Minecraft is more like scavenging underground using a pickaxe.
I like a lot of the ideas here, though I think the coding may be problematic in some aspects.
Specifically, with regards to rivers, another game I'm watching is procedurally generated and the dev had some interesting insight into why you can't really make realistic rivers in a procedurally generated game.
Let's rephrase the problem mathematically. Please forget about running algorithms on heightmaps, they cannot be used in this case.
Consider a function f that, given a latitude a / longitude b, returns the altitude h:
Code:
h = f ( a, b )
Simple enough, right ? f can be as simple or as complex as you want, and be a combination of many functions. For example, f can be a constant ( 0.0 ) meaning that all the terrain is at sea level. f can be a simple function, for example f = cos ( a ). In which case you'll get some terrain that varies between +- 1 Km depending on the latitude only.
To implement rivers, you need to modify f, let's say by adding a component g, that is only dependant on the same variables ( latitude/longitude ). In other words, you must find a function g that will be used like this:
Code:
h = f ( a, b ) + g ( a, b )
Now obviously rivers depend on terrain itself, meaning that to implement g you have to use f. However the only parameters are latitude/longitude (a, :cool.gif: meaning that you can only evaluate f at an offset based of (a, :cool.gif:, like ( a + dx, b + dy ).
Good luck.
Thought some of you might find that perspective interesting.
I just don't see this being fun at all though. Even if it was limited to certain areas on certain difficulties, I don't see what kind of challenge this adds to the game. Just a random annoyance that would lock down certain areas.
If you want environment-based dangers, add in hyper and hypothermia, and mix up mobs throughout biomes. Something that can actively be fought.
I disagree. Volcanoes would add a new depth to the game, which it certainly seems to be lacking in. Currently, if you have a fort you have guaranteed immunity (until you get griefed). This could make you add more walls to stem the flow of lava, and give you cause to watch the sky. If you don't like the danger, play on peaceful.
However, i do like the hyper and hypothermia ideas, and very much want mob-biome mix ups.
Support +1!
Rollback Post to RevisionRollBack
In the beginning the Universe was created. This has made a lot of people very angry and has been widely regarded as a bad move.
Currency in Minecraft?! Hell no! Anarcho-Communists of Minecraftia!
I disagree. Volcanoes would add a new depth to the game, which it certainly seems to be lacking in. Currently, if you have a fort you have guaranteed immunity (until you get griefed). This could make you add more walls to stem the flow of lava, and give you cause to watch the sky. If you don't like the danger, play on peaceful.
I don't see random, complete destruction as 'extra depth.' I see where you're going with this, but I just don't think it'd be fun. If you want a harder game, make more versatile mobs, or add depth to the resources (such as in this case of a more in-depth geology.)
Also, I figure that the danger in the game should mainly be something that comes with exploring, and is tamed by developing. It's why I'd like to see a new mob spawning mechanic. We can see it with the world now; venture into a cave and it's initially very dangerous. But plop down some torches and wall off some passages, and it's become safe. I just don't think a danger that's indiscriminate of that development perspective fits well with gameplay.
I'd prefer NOT for the limited amount of blocks Notch has left to make be taken up by 50 different types of rock, and not be used for fun/interesting stuff.
Sorry Blue vision but I don't think you are paying attention other peoples arguments.
For one we have already stated how it would be clearly defined - visible and avoidable
Secondly we have also suggested it could be turned off.
If we were unable to turn them off you can garentee a way to disable them using channelling or some minecraftian device.
Diamonds are already deep down and normally close to lava, thats a clear gameplay feature. You want rare and valuable you have hazards. Though I see your point when you say you dont want a pointless unstoppable destructive force in your game. This is obvious. We are not suggesting its added purely for the sake of depth as I presume you have read from other peoples comments.
The Nether is dangerous, its avoidable are you telling me you never go to the Nether?
People have build cities next to volcanoes for the duration of human history, that always have done and they still do today. Because the benefits counterbalance the danger.
Notch has already said Biomes will have a danger variable as mutch as they have rainfall and temprature.
I've read other people's arguments, and I still see it as a mechanic that'd add little depth to the game. You'd have to make the upsides monumental in order to "entice" people to actually build there, which kind of breaks the balance of resource distribution and such, and the only reward of the entire thing is hugely annoying failure when your house gets crumbled from an earthquake, or your garden turned into a moonscape from a volcanic eruption. There's no depth to that; just frustration.
Again, any kind of biome-based danger needs to be something that can actively be fought and developed against. The Nether is something that can be actively fought against; build fortresses to hole out against ghasts, attempt to kill them directly, dig mines through the ground to avoid them. You can't fight against an earthquake, you can only wait until it inevitably happens and rebuild from the rubble there. I see no fun or challenge in this; it's a gamble, while there's tonnes of possibility that can come from more versatile mobs, hyper/hypothermia, and more challenging/in depth construction.
EDIT: But PLEASE NOTCH, this thread needs to make it into an update very soon.
I'm not sure how true it is, but I keep hearing about a 265 block type limit.
The 265 block limit myth comes from there being only 265 spaces in the texture file. I don't think this is a real limit to block types however because programming language can support more than 265 variables and Notch could just add a second texture file
also +1
Rollback Post to RevisionRollBack
Quote from Chowder »
What is a unicorn if not a combustible equine psychopath?
I'd prefer NOT for the limited amount of blocks Notch has left to make be taken up by 50 different types of rock, and not be used for fun/interesting stuff.
Perhaps earthquakes would be better suited for SMP, because they tend to bring communities together, which would be somewhat difficult in Single Player...
On the other hand, Some earthquakes thrust the land up, creating more tiles at the bottom of the map, potentially bringing with them more rare minerals. Plus earthquakes can drastically alter the land, adding play value for those who like to explore.
Also, deep seafloor trenches (i.e. oceanic fault lines) could potentially harbor veins of diamonds owing to the huge amounts of pressure present in these areas. Pressure being one of the key ingredients in the production of diamonds.
Earthquakes (if something ever to exist) are something that would need an obvious visible environmental indicator, as to be something that could be easily avoided. The shaking could cause certain suspended blocks to fall, like gravel does. This is a risky maneuver, as it's essentially a small biome where construction is impossible. For that reason, though faults might be a good idea, earthquakes might not.
If natural disasters are something in the future, then having them with monsters might be redundant and simply add too much chaos to survival mode (they should only be in survival mode). That is, if they're something that's ever implemented, they should either be able to be toggled, or be a different setting of the game (survival monsters mode and survival natural disasters mode, for instance).
As far as rivers go, that's at the bottom of my list of suggestions due to how complex its implementation is, despite how drastically it would alter the terrain. Independent of any geology to Minecraft, the game simply needs rivers at some point. That means that an algorithm for rivers needs to be found somehow at some point. I'd consider this a very low priority, yet a very profound addition. One potential way to add it is simply to generate curvy lines on the terrain and fill them with water. Set their start and end points to areas tagged as "sea" or "lake" and have fun. Minecraft topography need not be realistic, per se, merely quasi-realistic as it is now.
Limestone's great, but marble definitely shouldn't exist in this level. Firstly, Marble should be hard to find, and secondly it's not realistic at all.
Where else would marble go? It's typically found near the surface and quarried out. It's really just lithified limestone, so I think it would be a bad idea to place it with deeper rocks. What do you mean about its placement being unrealistic?
Marble would be much easier to implement if you smelted limestone.
Hang on! If limestone is at the lot and the standard stone is underneath, it's going to be that much harder to craft furnaces, as cobblestone is underneath about 40 block's worth of limestone. Why dig down that far just to get cobblestone, which is and should always be one of the easiest materials in the game to get? Maybe you should have random seams of cobblestone running through the limestone layer, close to the top, where they're not too hard to find: just enough for a player to implement a cobblestone base with a furnace, stairs etc. Cobblestone is too important to be pushed into obscurity like that.
Rollback Post to RevisionRollBack
Quote from ash234 »
Quote from royman6 »
Quote from ash234 »
i just tryed cooking the milk but it didnt work you lier
YOUR A TROLL
No offence, but, you believed him?
yes i believed him i see the good in people but that usually turns out to me being tricked
I'm all for adding new block types for stone, that way they could be layered semi-randomly so the player might get a better indication of depth. Not to mention I now want to see a sedimentary cave (yay tan rock!)
Rollback Post to RevisionRollBack
Hell: When you're somewhere and stuff around you is on fire AND this is considered a natural feature of said environment, consider running away fast.
Hang on! If limestone is at the lot and the standard stone is underneath, it's going to be that much harder to craft furnaces, as cobblestone is underneath about 40 block's worth of limestone. Why dig down that far just to get cobblestone, which is and should always be one of the easiest materials in the game to get? Maybe you should have random seams of cobblestone running through the limestone layer, close to the top, where they're not too hard to find: just enough for a player to implement a cobblestone base with a furnace, stairs etc. Cobblestone is too important to be pushed into obscurity like that.
This is a fantastic criticism, thank you. I had completely overlooked it.
Changing the substrata of the Minecratian landscape does impact the availability of certain crafted items. Furnaces are one great example, stone tools would be another obvious one.
The solution might not have to be very complex, though!
Loose rocks, intrusions, and outcrops are good real world examples of how this problem could be avoided. Of course, they deal with problems when we get into biomes, but allow me to explain what I mean by these two things. An loose rock could simply be rock "beds" at or near the surface. It could be any type of bedrock, whether plain "rock" or granite or basalt. An intrusion is basically a pillar (vertical or linear) of igneous rock (like above) that is found beneath the surface or even near the surface. An outcrop is essentially when a rock layer is seen above the topsoil, which in this case, could be a bedrock outcroping (such as in a mountain or fault) on the surface.
What this would do, either way, is make rock more inaccessible at the beginning, sort of like coal is now. Of course, now that coal is resting in the sedimentary layer, it's more accessible. This makes the production of torches easier early game, but forces the player to search or dig a little longer before getting a furnace going (perhaps to make marble or slate). Personally, I find this shift acceptable, as I feel that finding torch materials before that first night much more important than building that first furnace. In fact, I remember one game where I built a few furnaces and fueled it with wood to have light due to my inability to make torches. This would, unintentionally, remedy that kind of situation.
This post is meant to explore the first stage of implementing minor geological improvements into Minecraft. Be aware that I haven't explored that actual coding behind map generation, so I'm not going to go into the sort of details explored earlier in this thread with mention to river implementation.
Step 1
The first step in implementing the ideas of this thread is with a simple line of demarcation between sedimentary and igneous rock followed by a modification of the distribution of materials found within.
Currently, "sea level" is a mere 64 blocks from the bottom of the map. What this means is that there is already limited space in the Minecraft subterranean world to include anything else. The total height of a map in Minecraft is 128. The first major change would be to increase the height of the typical Minecraft map, as adding another rock layer would only push the surface ever closer to the ceiling. This expansion of the Minecraft map will be the center topic of this post.
A safe change would be to increase the height to 256, as that would give plenty of room for possible further updates. This, additionally, could help to create even more distinctions between different biomes (which could be at different altitudes). With 128 extra squares to use, an average of 64 could be used for additional subterranean features with the other 64 allowing variations in altitude among various places in the Minecraft world (not to mention higher, more dramatic mountains).
Now that an average of 64 blocks is set aside to add more depth to Minecraft's underworld, we can begin to work with that line of demarcation. Currently a minimum of 64 blocks is "rock", so adding 64 new levels would effectively double the ground's mass. Half of the new addition could be added as sedimentary levels, giving an average of 32 blocks worth of new sedimentary material on the surface of the igneous layer.
With 64 blocks added to the previous 64, we see sea level rise at a whopping height of 128. That's the height of the current Minecraft map! These 128 blocks below the sea would have an average of 32 squares depth of sedimentary rock and 96 squares of igneous. Of course, this would vary from place to place. Also, above sea level, this could get much larger. A mountain, for example, might be 192 squares deep! As little as 0 squares of it might be sedimentary, as it varies (especially on mountains).
Now that we have a rough estimate for the average height of the sedimentary level (96 squares from the bottom), we can rearrange the minerals found there. In the layers starting at 96 and going up to 64 (or wherever sediment is located), coal will be found exclusively within easy reach to the newly spawned player. Iron will begin just underneath, at a rough depth of 32 squares from the surface. That's a lot deeper than before, but it will also appear in rock outcrops and stones (like beds of rock in dirt or the sedimentary layer), mountains, and other areas of exposed rock (which, remember, won't always appear beneath 32 squares of sediment, merely an average of that). Rather than pushing gold even further down, gold can appear in the same areas as iron, but less commonly. Also, veins of iron and gold should probably increase in size slightly. Iron in 4-6 blocks and gold in 3-4. With a deeper ground to mine in, the resource distribution should offset the added trouble. Diamond can stay at a low depth, but raised and widened in distribution to appear first about 32 squares from the bottom. Diamond "beds" don't need an increase in size, as their area is being drastically increased (even though the digging needed to get to them is also increasing dramatically).
Lava should simply not be found in sedimentary layers, but water should be. Water should stop appearing about the same time the igneous layer begins, 96 blocks from the bottom. Lava can appear anywhere at this time, with its frequency dramatically increasing as the player approaches the bottom. If a block should ever be removed, it should be adminium. Rather than this indestructible block, the base of any map could simply be a layer of lava. Perhaps the bottom 5-10 squares of all maps could be a solid mass of lava, with the ability to mine "layer 0" as impossible.
At this stage, we have a map 256 squares tall with the subterranean world divided between sedimentary and igneous rock and materials distributed between them. Below, caves can be more cavernous and above, terrain is free to explore different altitudes. In both, there is great potential for biomes (even underground biomes such as massive caves as seen in the Nether. After all, there's a whole Minecraft map above and below ground now. That's a lot to work with).
The obvious issue now is map generation and file size. Already, maps are divided into different files and worked with separately to aid in this. What this means is that increasing the Minecraft map size shouldn't have a noticeable performance impact for the player. In fact, the resulting file size increase is no more than currently achieved by exploring vast areas of the map currently and certainly doesn't compare to the size added by simply walking into the Nether. In short, this suggestion adds as much strain to the file size and map generation time as the Nether, while offering to implement a foundation for further Minecraft improvements such as those suggested in Oceancraft. Like this suggestion, Oceancraft would require a much larger subterranean world (especially to fit ocean trenches), and so would find its supporters enthusiastic towards the steps for implementing any further geology into Minecraft. The steps needed to expand Minecraft in this direction would also open up the possibility for other creative endeavors. Step one of my suggestion seems to rest at the core to many potential improvements, and so, even if the other ideas in this thread are ignored, this one should be weighted and considered carefully.
It (bizarrely, I know) occasionally really breaks the immersion for me that there aren't different rock strata. Again: I realize this makes me a crazy person.
If you want environment-based dangers, add in hyper and hypothermia, and mix up mobs throughout biomes. Something that can actively be fought.
IMO, having geological features to look for and go by makes Minecraft less tedious (and encourages surface exploration) than just randomly digging just anywhere knowing the map is evenly laced with small nuggets of resources differentiated only by vertical layers. After all, real mining involves digging in places where you are fairly certain something is deposited in significant quantities, but right now (praise be to Notch and so forth) Minecraft is more like scavenging underground using a pickaxe.
Specifically, with regards to rivers, another game I'm watching is procedurally generated and the dev had some interesting insight into why you can't really make realistic rivers in a procedurally generated game.
shameless plug /shameless plug
from http://www.infinity-universe.com/Infinity/index.php?option=com_smf&Itemid=75&topic=2391.msg317166#msg317166 :
Thought some of you might find that perspective interesting.
I disagree. Volcanoes would add a new depth to the game, which it certainly seems to be lacking in. Currently, if you have a fort you have guaranteed immunity (until you get griefed). This could make you add more walls to stem the flow of lava, and give you cause to watch the sky. If you don't like the danger, play on peaceful.
However, i do like the hyper and hypothermia ideas, and very much want mob-biome mix ups.
Support +1!
Currency in Minecraft?! Hell no!
Anarcho-Communists of Minecraftia!
Also, I figure that the danger in the game should mainly be something that comes with exploring, and is tamed by developing. It's why I'd like to see a new mob spawning mechanic. We can see it with the world now; venture into a cave and it's initially very dangerous. But plop down some torches and wall off some passages, and it's become safe. I just don't think a danger that's indiscriminate of that development perspective fits well with gameplay.
My Pathfinder Campaign for the denizens of MCF: http://www.minecraftforum.net/topic/1939035-where-are-we-sandbox-pathfinder-campaign-ooc/
Again, any kind of biome-based danger needs to be something that can actively be fought and developed against. The Nether is something that can be actively fought against; build fortresses to hole out against ghasts, attempt to kill them directly, dig mines through the ground to avoid them. You can't fight against an earthquake, you can only wait until it inevitably happens and rebuild from the rubble there. I see no fun or challenge in this; it's a gamble, while there's tonnes of possibility that can come from more versatile mobs, hyper/hypothermia, and more challenging/in depth construction.
EDIT: But PLEASE NOTCH, this thread needs to make it into an update very soon.
The 265 block limit myth comes from there being only 265 spaces in the texture file. I don't think this is a real limit to block types however because programming language can support more than 265 variables and Notch could just add a second texture file
also +1
Learn Hyperbole
My Pathfinder Campaign for the denizens of MCF: http://www.minecraftforum.net/topic/1939035-where-are-we-sandbox-pathfinder-campaign-ooc/
On the other hand, Some earthquakes thrust the land up, creating more tiles at the bottom of the map, potentially bringing with them more rare minerals. Plus earthquakes can drastically alter the land, adding play value for those who like to explore.
Also, deep seafloor trenches (i.e. oceanic fault lines) could potentially harbor veins of diamonds owing to the huge amounts of pressure present in these areas. Pressure being one of the key ingredients in the production of diamonds.
If natural disasters are something in the future, then having them with monsters might be redundant and simply add too much chaos to survival mode (they should only be in survival mode). That is, if they're something that's ever implemented, they should either be able to be toggled, or be a different setting of the game (survival monsters mode and survival natural disasters mode, for instance).
As far as rivers go, that's at the bottom of my list of suggestions due to how complex its implementation is, despite how drastically it would alter the terrain. Independent of any geology to Minecraft, the game simply needs rivers at some point. That means that an algorithm for rivers needs to be found somehow at some point. I'd consider this a very low priority, yet a very profound addition. One potential way to add it is simply to generate curvy lines on the terrain and fill them with water. Set their start and end points to areas tagged as "sea" or "lake" and have fun. Minecraft topography need not be realistic, per se, merely quasi-realistic as it is now.
Marble would be much easier to implement if you smelted limestone.
Hang on! If limestone is at the lot and the standard stone is underneath, it's going to be that much harder to craft furnaces, as cobblestone is underneath about 40 block's worth of limestone. Why dig down that far just to get cobblestone, which is and should always be one of the easiest materials in the game to get? Maybe you should have random seams of cobblestone running through the limestone layer, close to the top, where they're not too hard to find: just enough for a player to implement a cobblestone base with a furnace, stairs etc. Cobblestone is too important to be pushed into obscurity like that.
This is a fantastic criticism, thank you. I had completely overlooked it.
Changing the substrata of the Minecratian landscape does impact the availability of certain crafted items. Furnaces are one great example, stone tools would be another obvious one.
The solution might not have to be very complex, though!
Loose rocks, intrusions, and outcrops are good real world examples of how this problem could be avoided. Of course, they deal with problems when we get into biomes, but allow me to explain what I mean by these two things. An loose rock could simply be rock "beds" at or near the surface. It could be any type of bedrock, whether plain "rock" or granite or basalt. An intrusion is basically a pillar (vertical or linear) of igneous rock (like above) that is found beneath the surface or even near the surface. An outcrop is essentially when a rock layer is seen above the topsoil, which in this case, could be a bedrock outcroping (such as in a mountain or fault) on the surface.
What this would do, either way, is make rock more inaccessible at the beginning, sort of like coal is now. Of course, now that coal is resting in the sedimentary layer, it's more accessible. This makes the production of torches easier early game, but forces the player to search or dig a little longer before getting a furnace going (perhaps to make marble or slate). Personally, I find this shift acceptable, as I feel that finding torch materials before that first night much more important than building that first furnace. In fact, I remember one game where I built a few furnaces and fueled it with wood to have light due to my inability to make torches. This would, unintentionally, remedy that kind of situation.
The "strata" thing would solve the clay shortage too.
Edit: Speaking of, you should totally rename this topic Geocraft and we can combine Farmcraft, Oceancraft, and Geocraft into a supergame! =O
..maybe?
Have a modding question? PM me and hopefully I'll be able to help.
Check out my mod, LoMaS!
This post is meant to explore the first stage of implementing minor geological improvements into Minecraft. Be aware that I haven't explored that actual coding behind map generation, so I'm not going to go into the sort of details explored earlier in this thread with mention to river implementation.
Step 1
The first step in implementing the ideas of this thread is with a simple line of demarcation between sedimentary and igneous rock followed by a modification of the distribution of materials found within.
Currently, "sea level" is a mere 64 blocks from the bottom of the map. What this means is that there is already limited space in the Minecraft subterranean world to include anything else. The total height of a map in Minecraft is 128. The first major change would be to increase the height of the typical Minecraft map, as adding another rock layer would only push the surface ever closer to the ceiling. This expansion of the Minecraft map will be the center topic of this post.
A safe change would be to increase the height to 256, as that would give plenty of room for possible further updates. This, additionally, could help to create even more distinctions between different biomes (which could be at different altitudes). With 128 extra squares to use, an average of 64 could be used for additional subterranean features with the other 64 allowing variations in altitude among various places in the Minecraft world (not to mention higher, more dramatic mountains).
Now that an average of 64 blocks is set aside to add more depth to Minecraft's underworld, we can begin to work with that line of demarcation. Currently a minimum of 64 blocks is "rock", so adding 64 new levels would effectively double the ground's mass. Half of the new addition could be added as sedimentary levels, giving an average of 32 blocks worth of new sedimentary material on the surface of the igneous layer.
With 64 blocks added to the previous 64, we see sea level rise at a whopping height of 128. That's the height of the current Minecraft map! These 128 blocks below the sea would have an average of 32 squares depth of sedimentary rock and 96 squares of igneous. Of course, this would vary from place to place. Also, above sea level, this could get much larger. A mountain, for example, might be 192 squares deep! As little as 0 squares of it might be sedimentary, as it varies (especially on mountains).
Now that we have a rough estimate for the average height of the sedimentary level (96 squares from the bottom), we can rearrange the minerals found there. In the layers starting at 96 and going up to 64 (or wherever sediment is located), coal will be found exclusively within easy reach to the newly spawned player. Iron will begin just underneath, at a rough depth of 32 squares from the surface. That's a lot deeper than before, but it will also appear in rock outcrops and stones (like beds of rock in dirt or the sedimentary layer), mountains, and other areas of exposed rock (which, remember, won't always appear beneath 32 squares of sediment, merely an average of that). Rather than pushing gold even further down, gold can appear in the same areas as iron, but less commonly. Also, veins of iron and gold should probably increase in size slightly. Iron in 4-6 blocks and gold in 3-4. With a deeper ground to mine in, the resource distribution should offset the added trouble. Diamond can stay at a low depth, but raised and widened in distribution to appear first about 32 squares from the bottom. Diamond "beds" don't need an increase in size, as their area is being drastically increased (even though the digging needed to get to them is also increasing dramatically).
Lava should simply not be found in sedimentary layers, but water should be. Water should stop appearing about the same time the igneous layer begins, 96 blocks from the bottom. Lava can appear anywhere at this time, with its frequency dramatically increasing as the player approaches the bottom. If a block should ever be removed, it should be adminium. Rather than this indestructible block, the base of any map could simply be a layer of lava. Perhaps the bottom 5-10 squares of all maps could be a solid mass of lava, with the ability to mine "layer 0" as impossible.
At this stage, we have a map 256 squares tall with the subterranean world divided between sedimentary and igneous rock and materials distributed between them. Below, caves can be more cavernous and above, terrain is free to explore different altitudes. In both, there is great potential for biomes (even underground biomes such as massive caves as seen in the Nether. After all, there's a whole Minecraft map above and below ground now. That's a lot to work with).
The obvious issue now is map generation and file size. Already, maps are divided into different files and worked with separately to aid in this. What this means is that increasing the Minecraft map size shouldn't have a noticeable performance impact for the player. In fact, the resulting file size increase is no more than currently achieved by exploring vast areas of the map currently and certainly doesn't compare to the size added by simply walking into the Nether. In short, this suggestion adds as much strain to the file size and map generation time as the Nether, while offering to implement a foundation for further Minecraft improvements such as those suggested in Oceancraft. Like this suggestion, Oceancraft would require a much larger subterranean world (especially to fit ocean trenches), and so would find its supporters enthusiastic towards the steps for implementing any further geology into Minecraft. The steps needed to expand Minecraft in this direction would also open up the possibility for other creative endeavors. Step one of my suggestion seems to rest at the core to many potential improvements, and so, even if the other ideas in this thread are ignored, this one should be weighted and considered carefully.