Precambrian
Earth's earliest eon
Precambrian refers to the vast span of Earth's history before the Cambrian period—roughly the first 4 billion of the planet's 4.5 billion years.
During this time, life was mostly single-celled and left few fossils.
Precambrian rocks form the ancient cores of continents: Precambrian shield, Precambrian basement.
The term appears in geology and discussions of early Earth.
Earliest geological eon
- ProterozoicEon before complex life
- eonImmense time division
- deep timeImmense spans of Earth's history
- geochronologyStudy of geological ages
stratigraphy · geological history · radiometric dating · paleomagnetism · billion years · aeon · timescale
Foliated metamorphic rock
- schistPlaty-mineral metamorphic rock
- graniteIgneous rock, quartz-rich
- basaltFine-grained volcanic stone
- greenstoneMetamorphosed rock, often jade
quartzite · metamorphic · igneous · sedimentary · craton · shield · basement · outcrop
Prehistoric unified landmass
- ColumbiaAmerica personified, or its namesakes
- GondwanaAncient southern supercontinent
- UrEarly Mesopotamian metropolis
- supercontinentCombined planetary landmass
craton · orogeny · plate tectonics · continental drift · accretion · rifting · subduction · lithosphere
Layered sedimentary bacterial structures
- cyanobacteriaPhotosynthetic bacteria producing oxygen
- microfossilsMinute preserved organism remains
- prokaryotesOrganisms without membrane-bound nuclei
- eukaryotesNuclear-membrane organisms
archaea · algae · multicellular · oxygenation · biogenesis · abiogenesis · primordial soup · chemosynthesis
Existing from the start
- prehistoricBefore documented civilization
- primevalFrom earliest times
- antediluvianExtremely old or obsolete
- archaicBelonging to earlier times
earliest · remote · ancestral · age-old · oldest · primal · formative · foundational
Archean
Earliest geological eon
- ProterozoicEon before complex life
- eonImmense time division
- deep timeImmense spans of Earth's history
geochronology · stratigraphy · geological history · radiometric dating · paleomagnetism · billion years · aeon · timescale
gneiss
Foliated metamorphic rock
- schistPlaty-mineral metamorphic rock
- graniteIgneous rock, quartz-rich
- basaltFine-grained volcanic stone
greenstone · quartzite · metamorphic · igneous · sedimentary · craton · shield · basement · outcrop · zircon
Pangaea
Prehistoric unified landmass
- ColumbiaAmerica personified, or its namesakes
- GondwanaAncient southern supercontinent
- UrEarly Mesopotamian metropolis
supercontinent · craton · orogeny · plate tectonics · continental drift · accretion · rifting · subduction · lithosphere · paleogeography
stromatolites
Layered sedimentary bacterial structures
- cyanobacteriaPhotosynthetic bacteria producing oxygen
- microfossilsMinute preserved organism remains
- prokaryotesOrganisms without membrane-bound nuclei
eukaryotes · archaea · algae · multicellular · oxygenation · biogenesis · abiogenesis · primordial soup · chemosynthesis · anaerobic
primordial
Existing from the start
- prehistoricBefore documented civilization
- primevalFrom earliest times
- antediluvianExtremely old or obsolete
archaic · earliest · remote · ancestral · age-old · oldest · primal · formative · foundational
- erasera, epoch, age, bronze age, period
- time periodsday, year, month, week, hour
- Earth historyice age, geological time, extinction, eons, fossil
- geologic timeeons, eon, epochs, era, epoch
- Deep TimeArchean, Proterozoic, aeon, deep time
- Geochronologygeologic time, geologic time scale, time scale, timescale, deep time
PrecambrianCenozoic
Present geological era
Quaternary · Holocene · Cambrian · Cambrian explosion · Paleozoic