Discovery of radiometric dating
There were various attempts to estimate the Earth's age, working back from sedimentation rates and other geophysical phenomena.
The attempts produced estimates from about 100 million years up to several billion years. The first is that the geological history was still being reconstructed.
The physical models were open to question and, in retrospect, were naive. It became quite clear that many areas of the Earth had alternated between being land and being covered by seas, that there had been extensive slow sedimentation, that the mountains had not been created in situ as is but rather had a long history of slow deformation, and that long periods of erosion had shaped the Earth everywhere.
In Europe the issue of the age of the Earth was not a serious one prior to the rise of science; the history of the Earth was assumed to be accounted for in Genesis.
Descartes, however, attempted to discern a physical history of the Earth.