How to create the geological model if I have the mesh of all lithologies

If you have all lithology meshes you can create a solid model by 

* Import all meshes, make sure they have correct inside-outside orientaton. (volume should be positive)
* Create a geological model with no lithology, manually add those lithologies to model
* Create new intrusion by surface until you define all lithologies and set chronology


Note: If meshes are problematic, or cruscutting each other at very small amounts, the resolution and chronology will make difference and sometimes create problems. Consider assigning a background lithology to avoid crosscuts or repair meshes before use.