Geology=the science of, or the study of the earth. Principle of uniformitarianism(jer. 33:25) - natural laws work the same way today as they did long ago. "the present is the key to the past". Absolute (numeric) time = specifies an age in years. C14 n14: c14 = effective to 100,000 years - others up to 4. 6 billion years, varves a varve is one annual sediment layer, dendrochronology this is tree ring dating. Geologic time scale is divided into eons, which are divided into eras, which are divided into periods, which are divided into epochs.