Dating on earth dbsk wiki
Steno's ideas also lead to other important concepts geologists use today, such as relative dating.
Over the course of the 18th century geologists realized that: The Neptunist theories popular at this time (expounded by Abraham Werner (1749–1817) in the late 18th century) proposed that all rocks had precipitated out of a single enormous flood.
Apart from the Late Heavy Bombardment, events on other planets probably had little direct influence on the Earth, and events on Earth had correspondingly little effect on those planets.
Construction of a time scale that links the planets is, therefore, of only limited relevance to the Earth's time scale, except in a Solar System context.
The first three of these can be referred to collectively as the Precambrian supereon.
Eons are divided into eras, which are in turn divided into periods, epochs and ages.
Therefore, the second timeline shows an expanded view of the most recent eon.
In a similar way, the most recent era is expanded in the third timeline, and the most recent period is expanded in the fourth timeline.
The three million year Quaternary period, the time of recognizable humans, is too small to be visible at this scale.Some other planets and moons in the Solar System have sufficiently rigid structures to have preserved records of their own histories, for example, Venus, Mars and the Earth's Moon.Dominantly fluid planets, such as the gas giants, do not preserve their history in a comparable manner.The following four timelines show the geologic time scale.The first shows the entire time from the formation of the Earth to the present, but this gives little space for the most recent eon.