I'd wager it really depends on the culture.
I just had an interview at a geology school in Texas. I wore khaki jeans, a nice pair of cowboy boots, and a button down. I frankly think I may have over dressed given that one of the professors greeted me in a T-shirt and jorts. All of the other professors had on blue jeans.
Again, though, it really depends on the culture of the school and the department/major. I was a political science major for a while and the poly-sci professors I had were always dressed more formally than my geology professors.
The outfit you described would probably be good, though. A suit or something similar would probably be a little too much. Good luck!