Its all about MINECRAFT here ;-)

 

More Details

I want to explain some more about the often used features in TC Mod.

To get layers of different material, just use the setting ReplacedBlocks: like this:
ReplacedBlocks:1=12(65-78),1=73(89-94),1=57(105-112),82=80(128-160)

This will give You for instance colored mountains like this:

....................................................................................................................................................................................................................................................................
To get better looking and smooth transition from the very steep increase of extreme mountains and even get more summits as Isles in it too, You may work like this:.
Use the "Isle in Isle" style and additional the  "Border of" settings in worldConfig and the associated Isle and border Biomes.

The map image here shows some extreme summits (+200, red and purple colors) right in the extreme Mountains (+120, dark green/brown colors).
The yellow part is desert Biome with some desert Hills (brown color) in it.
Transitions can be made smother by using the "border of" biome like "Extreme Hills Edge" and adjust its height a little more +.
To get it too work for the summits, just copy it, rename it and set its height values even more to +.
Its a little difficult to get the right feeling for the values, but  working in small steps one by one will soon give nice results like this:

This are the settings in worldConfig.ini:

NormalBiomes:Extreme Hills,Desert
IsleBiomes:DesertHills,MushroomIsland,River,Summits,Summits2
BorderBiomes:Beach,Extreme Hills Edge,MushroomIslandShore
CustomBiomes:Summits,Summits2

Beach is BiomeIsBorder:Ocean, DesertHills is IsleInBiome:Desert,
Extreme Hills Edge is BiomeIsBorder:Desert

Extreme Hills is BiomeIsBorder:Summits,Summits2 Rivers are set to BiomeRivers:false in DesertHills, Extreme Hills, Summits and Summits2.
 

The Image on the left shows, how to use the Border Biome Extreme Hills Edge to smooth out the transition of relative flat land biomes (like Desert) to extreme Mountains.

In the background, one of the summit biomes pikes out.

................................................................................................................................................................................................
Let us see now, how to get one single biome floating in the air. This is very simple, just set this in its biomeConfig.ini from false to true: DisableBiomeHeight:true
You will get this: