It's one of those things where it would mean so little, but if it's a geological formation from before human history, the butterflies could be enormous.
If freakishly everything progressed in the same way for quite some time, the first major thing I can think of is that the Japanese would not have been able to take it from the Chinese after the/a Sino-Japanese war. If THAT doesn't butterfly away a defeat of a Nationalist Chinese party by a Communist party, those Chinese would have nowhere to retreat to, and there would be no surviving secondary republic of China unless it was in Hainan or something, which would have most likely fallen eventually.