Implementing a quadtree LOD system to a cube-sphere

As it stands, I have a cube-sphere that has some layered noise applied, to act as a planet with realistic terrain, however I want to implement a LOD (Leve of Detail) system so that when the user moves closer to the cube-sphere, the closest face will split into four faces, hence the quadtree, and increase in detail more and more the closer the user gets, having the seems of the faces line up with different levels of detail is also an issue, any help would be appreciated as well as links to resources :).

Use LOD Groups