Theoretically all the information someone absorbs is going to be consciously vs. unconsciously absorbed to different degrees. I would say that if the information is easier to remember then you are using your unconscious mind (like how songs are easy to remember). Songs are easy to remember because they are fun, a persons emotions are evoked and that helps increase mental processing of the song so they can recall it. The emotion 'fun' from the song (even if it is a sad song the fact that it is a song is positive) or just emotion from the song helps you to remember it.
Information that you don't need to think about that much consciously is unconscious information as well. If you think about it, if you have to do a lot consciously - like think of this and that in order to remember something or think or do something, then it is more conscious. If it is done more automatically then it is more unconscious.
I would say that all emotional information is more unconscious. Dreams are emotional because you are not conscious during them. That is why they don't make sense, because you are not thinking (lol). Does this mean that someone thinking a lot is going to be less emotional? That is hard to say because you can't really define when someone as thinking a lot or not. If someone is watching a movie, they are probably thinking less then when during a history exam.
So my theory is that knowing how emotional something is can help classify if it is intellectually intense or not. For example - which would use more thought, a math test or a history test? In history you use emotional information to help remember the facts. What happened in history is emotional and social. Math is logical, it is clear how to get the result if you understand how things work in a concrete, straightforward way. (I am not saying that calculus is straightforward, I am just saying that it makes sense why it works that way because math makes sense). History is a social subject, however, so ones understanding of emotion and human interaction is going to influence your ability to do well in that field.
So which subject uses more unconscious processes? History or math? I would say that history does since it is emotional, and math doesn't necessarily engage any emotions. I mean, you are just doing numbers, it could cause someone to become emotional if it brings up something indirectly, but that would not relate directly to the math problem like how historical fact relates to social interaction.