Introduction to Historical Geology Introduction to Historical Geology Historical Geology is the study of changes to Earth and life in time and space. Oldest meteorites and oldest moon rocks are 4.6 billion years old 4,600,000,000 years Oldest rocks found so far on Earth are zircon grains from a sandstone in western Australia, dated at 4.1 to 4.2 bilion years old. Previously, the oldest Earth rocks were 3.96 billion years old, from the Northwest Territories of Canada.
Radioactive materials serve as geologic clocks.
All of these natural events are still going on today - We see evidence in the rock record that these events have been occurring for a long time. Geologists call this uniformitarianism. The physical laws governing the universe operate uniformly through time. See Levin, 6th edition, p. 6-7. The geologic record consists of rock units , each of which records some event or series of events that occurred in the past.