1. I didn't date the Flood to circa 4,500 BCE.
2. You are using circular logic. 99% of ALL fossils extant are marine. Perhaps the fossils are dated incorrectly. You cannot carbon date a 33-million-year-old organic anything. You look at surrounding rocks and make... assumptions.
Genesis 5.3: And Adam lived an hundred and thirty years, and begat a son in his own likeness, and after his image; and called his name Seth:
Genesis 5:6 And Seth lived an hundred and five years, and begat Enos:
Total: 130+105 = 235 years
Genesis 5:9 And Enos lived ninety years, and begat Cainan:
Total: 235+90 = 325 years
Genesis 5:12 And Cainan lived seventy years and begat Mahalaleel:
Total: 325+70 = 395 years
Genesis 5:15 And Mahalaleel lived sixty and five years, and begat Jared:
Total: 395+65 = 460 years
Genesis 5:18 And Jared lived an hundred sixty and two years, and he begat Enoch:
Total: 460+162 = 622 years
Genesis 5:21 And Enoch lived sixty and five years, and begat Methuselah:
Total: 622+65 = 687 years
Genesis 5:25 And Methuselah lived an hundred eighty and seven years, and begat Lamech.
Total: 687+187 = 874 years.
Genesis 5:28 And Lamech lived an hundred eighty and two years, and begat a son:
5:29 And he called his name Noah, saying, This same shall comfort us concerning our work and toil of our hands, because of the ground which the LORD hath cursed.
Total: 874+182 = 1056 years
Genesis 7:6 And Noah was six hundred years old when the flood of waters was upon the earth.
Total: 1056+600 = 1656 years
This gives the date of the flood according to the Bible.
Genesis 8:13 And it came to pass in the six hundredth and first year, in the first month, the first day of the month, the waters were dried up from off the earth: and Noah removed the covering of the ark, and looked, and, behold, the face of the ground was dry.
Total: 1056+601 = 1657 years
This gives the date of the end of the flood.
Genesis 11:10 These are the generations of Shem: Shem was an hundred years old, and begat Arphaxad two years after the flood:
Total: 1657+2 = 1659 years
This is a bit ambiguous: is the two years measured from the beginning or the end of the flood? I used the end of the flood.
Genesis 11:12 And Arphaxad lived five and thirty years, and begat Salah:
Total: 1659+35 = 1694 years
Genesis 11:14 And Salah lived thirty years, and begat Eber:
Total: 1694+30 = 1724 years
Genesis 11:16 And Eber lived four and thirty years, and begat Peleg:
Total: 1724+34 = 1758 years
Genesis 11:18 And Peleg lived thirty years, and begat Reu:
Total: 1758+30 = 1788
Genesis 11:20 And Reu lived two and thirty years, and begat Serug:
Total: 1788+32 = 1820 years
Genesis 11:22 And Serug lived thirty years, and begat Nahor:
Total: 1820+30 = 1850 years
Genesis 11:24 And Nahor lived nine and twenty years, and begat Terah:
Total: 1850+29 = 1879 years
Genesis 11:26 And Terah lived seventy years, and begat Abram, Nahor, and Haran.
Total: 1879+70 = 1949 years
Genesis 21:5 And Abraham was an hundred years old, when his son Isaac was born unto him.
Note: Abram and Abraham are the same person.
Total: 1949+100 = 2049 years.
Genesis 25:26 And after that came his brother out, and his hand took hold on Esau's heel; and his name was called Jacob: and Isaac was threescore years old when she bare them.
Total: 2049+60 = 2109 years
Genesis 47:28 And Jacob lived in the land of Egypt seventeen years: so the whole age of Jacob was an hundred forty and seven years.
Total: 2109+147 = 2256 years
This means that Jacob went into Egypt at
Total: 2256-17 = 2239 years.
Exodus 12:40 Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years.
Note: this is an over-estimate: some people think the 430 years starts when Abraham went into Canaan.
Total: 2239+430 = 2669 years.
1 Kings 6:1 And it came to pass in the four hundred and eightieth year after the children of Israel were come out of the land of Egypt, in the fourth year of Solomon's reign over Israel, in the month Zif, which is the second month, that he began to build the house of the LORD.
Note: some would add to this the 40 years in the desert.
Total: 2669+480 = 3149 years.
The temple stood for 410 years:
Total: 3149+410 = 3459 years
Destruction of the temple of Solomon by Neuchadnezzer was in 587 BC.
This means that Adam was formed 3459+587 = 4046 BC.
The global flood ended 4046-1657=2389 BC.
Note: If you think the 430 years starts when Abraham went into Canaan, the dates would be:
Adam formed: 4006 BC
Global flood end: 2349 BC
If you think the 2 years for the begetting of Arphaxad was at the beginning of the flood, then the dates are
Adam formed: 4004 BC
Global flood ended: 2347 BC