Precambrian: Quick Facts

Written and fact-checked by

The Information Architects of Encyclopaedia Britannica

Facts

Also Known As	Precambrian time • pre-Phanerozoic time

Photos

A detailed geologic time scale chart displaying Earth's history from the Hadean Eon over 4.5 billion years ago to the present, organized by eons, eras, periods, epochs, and ages with color-coded columns and corresponding dates in millions of years.

A vertical chart of the Archean eon within the geologic time scale, showing its four subdivisions-Neoarchean, Mesoarchean, Paleoarchean, and Eoarchean-alongside their starting points in millions of years ago, with the Hadean interval beneath and labeled as informal.

A chart showing the Proterozoic eon on the geologic time scale, divided into Paleoproterozoic, Mesoproterozoic, and Neoproterozoic eras with their respective periods and the millions of years ago each period began, ranging from 2,500 to about 539 million years ago.

Clusters of dark, rounded living stromatolites cover the sandy shore at Hamlyn Bay, Western Australia, with shallow turquoise water in the background.

Spriggina fossil

Precambrian bedrock of the Canadian Shield rising out of Reindeer Lake, on the border between northeastern Saskatchewan and northwestern Manitoba.

North West Leicestershire

Whaleback outcroppings of Precambrian granite of the basement complex in the Matopo Hills, southwestern Zimbabwe.

A colorful diagram of the geologic time scale shows major eons, eras, and periods, with illustrations of key prehistoric life forms such as bacteria, jellyfish, trilobites, fishes, dinosaurs, mammals, and humans, spanning from 4,000 million years ago to the present. Measurement bars at the top and bottom indicate the passage of time in millions of years, and each section is color-coded to highlight evolutionary milestones.

See All Images →

Topics

Archean Eon Proterozoic Eon Hadean Eon Precambrian Eonothem Primary granulite–gneiss belt greenstone-granite belt Cryptozoic Eon fossil Ediacara fauna Phanerozoic Eon Lipalian interval geochronology How Old Is Earth?A Journey Through Time Since the Precambrian era epoch period eon

Dig Deeper: More Articles That Discuss This Topic

North America: Precambrian time

Key People

Sederholm

Jakob Johannes Sederholm

Finnish geologist