Lore Question Regarding Elemental Manipulation

[Marauder]

So, I had a question earlier.

Can an Elemancer manipulate pre-existing materials? For example, would it be possible for a skilled Hydromancer to stand in a stream and cause small geysers with some concentration? The element would obviously be in physical contact and they'd have to be capable of channeling, maybe have an open Hydromancy channel too?

I require this information before I start spewing ideas for Geomancy and probably Hydromancy, too.

[CLOK]

Elemancers can't manipulate pre-existing elements. Only the elements they themselves have conjured.