The 300-500ft sea level rise at the end of the last Ice Age flooded the continents sometimes hundreds of miles inland.
Take a look at this map of the world's oceans lowered by about 300 ft. Notice that there's no Persian Gulf, the Red Sea is land locked, the Mediterranean was seperated into at least three segments and I speculate that the Gulf Of Mexico was sealed off also, etc. That was a worldwide flood.
Indeed. And not the only time it happened. But way too early for Noah, and not covering the tops of the highest mountains as the Bible said.
Biblical chronology is fairly straightforward. Certain historical personages such as Cyrus the Great can be independently dated tracing back from the present. From there it is just a question of following the Bible. Given a bit of ambiguity, Noah is 4000 BC or so.
A miraculous flood is a defensible position, but it isn't science.
The mythological approach has its problems also. Given the precision of Biblical chronology, at what point does it become pure myth?
I tend toward the mythological approach myself, but if I'm proven wrong it won't be by geology. You'll have to convince me that science isn't the last word on the subject.