The unexplainable was how wegener prove that pangaea was existed before the evidences are not much proven enough to establish that it was fact. was he lived on the time when pangaea existed? a million years after? the pangaea separated because of earthquake? how about the mechanism within the earth when the time pangaea existed? sometimes it makes sense because of remaining fragments of ancient animals and the evidence of jig saw puzzles, the continents just like a puzzle that every edges could fit each other, the evidences of rocks and the interpretation of the widening of ocean basins but it still a theory right and no exact answer right away :)