I don't quite understand the Earth Science department at Oxford. I went on an open day about a year ago and I spoke to the tutor at St Edmund Hall. He asked me what I was currently studying (which at the time was chemistry, geography, physics and geology), when I'd said what I was doing he said "So, no maths then?".
I did tell him that I'd been doing geology since GCSE, but he didn't seem to care at all. All he was interested in was maths, and to be honest I do not want to do a maths degree, so that's why I haven't applied.
There was someone else there who said they were doing chemistry, biology and maths (no geology or even geography) and he was absolutely fine because they mentioned maths.
Ah well...