This behaviour pack adds new generation under y level 0, which is already included in Minecraft Java edition snapshots, however so far on Bedrock edition there is no interesting generation down there. 

This pack includes generation of following blocks and features under the y level 0:

• Deepslate
• Stone (only between levels 0 and -8)
• Glow lichen
• Dripstone block
• Pointed dripstone
• Tuff block
• Brown and red mushroom
• Water source block and flowing water
• Lava source block and flowing lava
• All ores corresponding for y levels under 0
• Amethyst geodes
• Mineshafts

Because this pack adds a new generation to the game, it can impact loading time for your worlds, expect longer loading times depending on performance of your hardware. I recommend enabling only experiments needed for the pack for the best performance. Be patient while creating and loading your worlds.

Following experimental features are needed for the pack to work!

If you want to see some examples of the generation, take a look at the screenshots provided below.

Comparison:

With pack:

Without pack:

Cavern lake:

Some cave:

Dripstone:

Mineshaft:

If you find any bug or issue, make sure to report it on our Discord Server with great community.
This behaviour pack is made by Studio IceCraft and restricted under this license. If you wish to share this content with others make sure to credit with link to this post!

Enjoy playing with this behaviour pack! 🙂