The great debate was won by the uniformitarians, so much so that the degree of gradualism was overstated and the importance of catastrophes was unduly minimized.
The modern period has been marked by an enormous expansion of the detailed knowledge of the geological history of the Earth and the processes that have acted during that history.
Ussher accepted the Biblical account at face value, relying on the Biblical genealogies and on extant historical records.
He implicitly assumed that the world was created much as it is now.
The second is that the rates of the physical processes in question are variable and knowledge of them was incomplete.
In the late 1800's physicists, armed with a more advanced physics than that available to Descartes, made new estimates of the age of the Earth and the Sun.
It was not ruled out, per se, but it was not necessary. In the new science, however, rational explanation was desirable. In 1640 Ussher produced his famous calculation that the Earth was created in 4004 BC.
In 1637 Descartes produced a cosmogony that was highly influential for more than a century. It was not in their estimates of the age of the Earth - Descartes retained the biblical date.The rise of science produced a major change in attitude.In the pre-scientific world view the issue of the age of the Earth was a theological question.If, in the year AD 1600, you had asked an educated European how old the planet Earth was and to recount its history he would have said that it was about 6000 years old and that its ancient history was given by the biblical account in Genesis.If you asked the same question of an educated European in AD 1900 you would have received a quite different answer.He would have answered that the Earth was ancient, that there had not been a Noachian flood, and that the species of life had not been fixed over the history of Earth.