Mechanically what you see is what you get, but we all use our imagination when making things from the default classes. I have an unsubmitted druid that uses bones for divination, and my main character is a sandcaller. It is not uncommon for Lucindites to be both wizard and priest - Queen Allurial herself should be considered a mystic theurge, in a way, hm? It's one of the reasons she so united Lucinda's church and set the pattern of Lucinda's favor, the calling both arcane and deity-granted. Since all you really need to do in concept is do both arcane and divine, which is easy
mechanically, I don't see why seeking a merging of them is out of character nor completely lacking in any foundation.
The sandcallers in the desert shape the environment and depend on it, caring for the place around them - with arcane magic. Certainly not a geomancer, but depending on what someone is looking for in concept it is actually kind of similar. Let's not be hasty with "no basis" answers. Someone could try anything, though it doesn't mean they would succeed.

The blending of arcane and divine is not new. The class names don't exist, but depending on what you are looking for there could be things hiding under rocks.