Geological time and radiometric dating catholic christian dating online
The time scale is constantly being refined, so don't be surprised to see continuing revisions as our technology and understanding of the Earth improves!
The written record of human history, measured in decades and centuries, is but a blink of an eye when compared with this vast span of time.
Piece by piece, geologists constructed a geologic time scale, using increasingly more sophisticated methods for dating rock formations.
Early geologists used the relative positions of rock layers as clues to begin to unravel the complex history of our planet.
The older layers are lower 'relative' to the younger layers.
Long before scientists had developed the technology necessary to assign ages in terms of number of years before the present, they were able to develop a 'relative' geologic time scale.
Older periods which predate the reliable fossil record are defined by absolute age.