This period covers two geological eras: the Noachian, which ran from 4.1 to 3.7 billion years ago, and the Hesperian, which endured from 3.7 to about 3 billion years ago. The Noachian is ...

Some scientists are calling it the Anthropocene era, or the age of the humans ("anthropos" is Greek for human), and argue ...

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 ...

Geological eras and periods with relative times (Myr ago) are indicated on the left. Mammal lineages are in red; diapsid reptiles, shown as archosaurs (birds, crocodilians and dinosaurs), are in ...

The Stratigraphy and Paleontology Hall displays in chronological order a collection of fossils representing each of the geological eras beginning from the late Precambrian period in China.

There are three general approaches that allow scientists to date geological materials and answer the question: "How old is this fossil?" First, the relative age of a fossil can be determined.

"Readers will learn about the changing dynamics of atmospheric oxygen, temperature, and carbon dioxide during different geological eras. In addition, readers will understand relationships among ...

Geologic mapping has been one of the most fundamental mandates of the U.S. Geological Survey (USGS) since its establishment in 1879. Congress created the USGS to “classify the public lands and ...