I am not a Conjuror, but I believe I know what you and the player you mentioned are talking about. Within the specialized class skill tree are the lines of your combat arts (i.e. every art you obtain associated with that particular icon, upgraded every 14 levels). These trees are not linear like the sub-class trees. Instead, and I'm sure you have already noticed this, you may have to put points into 1 - 3 lines of combat arts before your tree actually coincides with the next line of arts you want to enhance. Basically, every point spent on one of the lines of art in this tree increases the effectiveness of that particular line of arts.
So here is what happened: Geotic Brand (not Seal btw) is the level 40 version of Earthly Brand. Both of these combat arts share the same reuse timer and are therefore considered part of the same line of combart arts. In order to increase the effectiveness of Geotic Brand, you have to spend points in your tree on the lowest version of that spell. Look for the icon in your tree that coincides with the Earthly Brand icon. That is the one you want to pump points into.
As to your question regarding Abjuration, Minstration, etc: those skills have a chance of increasing in level every time you use a particular spell of that kind. You can see your current skill level by going into your personna window and clicking on Skills. It will list the name of the skill and also the current level of that skill versus the maximum level you are allowed to obtain based on your current adventure level (It will look like this: 150/190).
Hope that helped.
Edited, May 7th 2007 7:58pm by Mearyk