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, ...

The age of the fossil must be determined so it can be compared to other fossil species from the same time ... any geologic features that cut across strata must have formed after the rocks they ...

Prehistoric time line, geologic time scale, photos, facts, maps, and more from National Geographic. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.

There is little dispute within the scientific community that humans are changing Earth's climate on a decadal to century time-scale. By the end of this century ... the National Research Council ...

Over deep, or "geologic," time, and with the right temperature, chemical, and pressure conditions, hard rocks are formed from soils, sands, silts, muds, ashes and other types of loose sediment.

According to the International Union of Geological Sciences (IUGS), the professional organization in charge of defining Earth’s time scale ... you start naming geologic-time terms, you need ...

I like to use a meter stick and be very intentional with my spacing to model time as a scale. I also avoid using the far right ... of the Earth that is characteristic of a particular span of geologic ...