Ore generation question

[Recon]

I've noticed something causing ores to generate oddly.

Specifically I've noticed a bit of Lapis at around Y55 which I've never seen before, but when I look around for it now I am not seeing it anywhere. Its very odd since it is usually quite abundant at the lower levels. But after spending a half hour digging fast, I haven't turned up one bit. Could be bad luck maybe but seems unlikely. I also noticed silver and lead rather high up. Y50 or so. There seems to be an unusually high number of diamonds too. Definitely seeing them spawning in clusters a short distance from each other where I am used to them being rather difficult to find. I'm using 1.6.4, and most of the mods in the DW20 pack. Its likely a config option but I can't think of what would cause lapis to spawn so high.

I did notice in CoFHWorld-Generation.cfg that there is a section for Lapis
It says MaxVar=40 MeanY=20 NumClusters=2
This is different than other ore sections, which have MaxY and MinY. MaxVar and MeanY I am not sure what they are referring to. It seems Thermal Expansion controls vanilla ores by default (Replacement = true) but I am suspicious about the MaxVar and MeanY values for Lapis. Anyone know what these mean?

Also silver in the config says MaxY = 32 but I've definitely seen it above that level.

 

[Padfoote]

Assuming here, as I haven't experimented with the config at all, but MeanY is most likely the average Y value that lapis can spawn at, with MaxVar being the maximum variance from this value that you could see. So with a MeanY of 20 and a MaxVar of 40, you could see lapis as high as y=60.

Of course, this is all assuming that I'm correct in my guess here.

 

[Recon]

Well its as good a guess as anything I've got! It makes sense, thanks.

 

[Scopius]

I believe Biomes O'Plenty causes certain ores to only spawn in certain biomes. Like Emeralds in Forest type biomes. I remember reading about where Lapis spawns in that group, but don't remember where.

 

[SandGrainOne]

I believe Biomes O'Plenty causes certain ores to only spawn in certain biomes. Like Emeralds in Forest type biomes. I remember reading about where Lapis spawns in that group, but don't remember where.

Emerald only spawning in Extreme Hills is a vanilla Minecraft feature, but I there is a good chance that some mod changes that.

In Vanilla, Lapis is generated differently from other ores. Lapis prefers one layer with a chance to be spawned above or below. Spawn chance decrease more and more as you go up or down, away from the ideal layer. The other ores are generated in a more uniform manner in a layer range. This might be why the config options look differently for Lapis.