We will provide a list of web sites with relevant information. The geologic time scale is divided into eons, eras, periods, epochs, and ages. Our activities, and the time scale for download above, ...

Prehistoric time line, geologic time scale ... The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles. Dinosaurs ruled the Earth in the mighty ...

THE present short article is a reversion to an aspect of the subject of geologic time which I had thought to be settled, and to require no further research or controversy. In my review of Mr.

Time is fundamental to Earth science. Geochronology data are essential for determining the timing, duration, and rates of Earth processes and events, and are increasingly required to perform modern, ...

Understanding Earth's Deep Past provides an assessment of both the demonstrated and underdeveloped potential of the deep-time geologic record to inform us about the dynamics of the global climate ...

Numerical ages estimate the date of a geological event and can sometimes reveal quite precisely when a fossil species existed in time. Third, magnetism in rocks can be used to estimate the age of ...

What era is formation of Earth's atmosphere? In the six billion year period ago Earth cooled, and gases ejected from volcanoes created an atmosphere. The atmosphere at that time, however, contained ...