Borass is famous for putting forth the theory that the fossilized magical fields in long-buried rocks showed the occasional reversal of the Discworld's direction of spin. He is also known for several other theories about what is essentially Discworld geology; that rocks found deeper underground are likely to be older than rocks on top (instead of being arranged by colour, as was the commonly held theory at the time), that mountains gradually turn into grains of sand (instead of the other way round, as dictated by common sense), and that the continents of the Disc were all formerly one landmass, which he named Pangola. He was also responsible for naming the Borassic Era, the time when Pangola split into two smaller landmasses (which he named Howondaland and Lauragatea, and also for claiming that XXXX was part of Lauragatea that wandered off in search of 'the geographical equivalent of a nice cool drink'.
He would have been more highly regarded among his fellow wizards if it wasn't for the fact that he was insistent that curious monsters had existed on the Discworld before the arrival of men, dwarfs and trolls. He extrapolated from a fragment of what he said was fossil bone, and some of his drawings survived. His fellow wizards, however, took the view that 'any god worth bothering, and who had something to say about Creation and all the rest of it, would write it all down fair and square somewhere, and would have too much respect for their creations to expect them to go grovelling around in some kind of cosmic game of Hunt the Slipper.'
Borass was forced to go back and teach students at Unseen University. He died soon afterwards, and it was later claimed that the 'fossil bone' was in fact an old spoon handle.