Eoarchean Era
E229220
The Eoarchean Era is an ancient division of Earth's early history marked by the formation of the first stable continental crust and some of the oldest known rocks and possible signs of early life.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Eoarchean Era canonical | 3 |
| Eoarchean | 1 |
| Eoarchean System | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1966306 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Eoarchean Era Context triple: [Precambrian Supereon, contains, Eoarchean Era]
-
A.
Paleoarchean Era
The Paleoarchean Era is an early division of Earth's geologic history marked by the stabilization of the first continental crust and the emergence of some of the oldest known life forms.
-
B.
Archean Eon
The Archean Eon is an ancient geological eon of Earth's history, spanning from about 4.0 to 2.5 billion years ago, characterized by the formation of the first stable continental crust and the earliest known life.
-
C.
Precambrian Supereon
The Precambrian Supereon is the vast span of Earth's early history before the Phanerozoic, encompassing the Hadean, Archean, and Proterozoic eons during which the planet formed, life first appeared, and early continents and atmospheres developed.
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D.
Hadean Eon
The Hadean Eon is the earliest interval of Earth's history, marked by planetary formation, intense bombardment, and a largely molten surface before the emergence of stable crust and oceans.
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E.
Paleoproterozoic Era
The Paleoproterozoic Era was an early division of Earth's history marked by the stabilization of continental cratons, widespread banded iron formations, and the Great Oxidation Event that significantly increased atmospheric oxygen.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Eoarchean Era Target entity description: The Eoarchean Era is an ancient division of Earth's early history marked by the formation of the first stable continental crust and some of the oldest known rocks and possible signs of early life.
-
A.
Paleoarchean Era
The Paleoarchean Era is an early division of Earth's geologic history marked by the stabilization of the first continental crust and the emergence of some of the oldest known life forms.
-
B.
Archean Eon
The Archean Eon is an ancient geological eon of Earth's history, spanning from about 4.0 to 2.5 billion years ago, characterized by the formation of the first stable continental crust and the earliest known life.
-
C.
Precambrian Supereon
The Precambrian Supereon is the vast span of Earth's early history before the Phanerozoic, encompassing the Hadean, Archean, and Proterozoic eons during which the planet formed, life first appeared, and early continents and atmospheres developed.
-
D.
Hadean Eon
The Hadean Eon is the earliest interval of Earth's history, marked by planetary formation, intense bombardment, and a largely molten surface before the emergence of stable crust and oceans.
-
E.
Paleoproterozoic Era
The Paleoproterozoic Era was an early division of Earth's history marked by the stabilization of continental cratons, widespread banded iron formations, and the Great Oxidation Event that significantly increased atmospheric oxygen.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
geological era
ⓘ
subdivision of the Archean Eon ⓘ |
| atmosphere |
anoxic atmosphere
ⓘ
very low free oxygen levels ⓘ |
| boundaryType |
Global Standard Stratigraphic Age boundary
ⓘ
linked to:
Global Boundary Stratotype Section and Point
|
| characterizedBy |
formation of early cratons
ⓘ
formation of first stable continental crust ⓘ high heat flow from Earth’s interior ⓘ intense meteorite bombardment tail end ⓘ oldest well-preserved rocks ⓘ possible earliest evidence of life ⓘ |
| chronostratigraphicUnit |
Eoarchean System
ⓘ
linked to:
Eoarchean Era
|
| climate | likely hot surface conditions ⓘ |
| contains |
some of Earth’s oldest known rocks
ⓘ
some of Earth’s oldest known zircons ⓘ |
| definedBy | absolute age boundaries rather than stratotype section ⓘ |
| endTime |
3600 million years ago
ⓘ
about 3.6 billion years ago ⓘ |
| etymology |
from Archean referring to ancient
ⓘ
from Greek eos meaning dawn ⓘ |
| follows | Hadean Eon ⓘ |
| geochronologicUnit |
Eoarchean
ⓘ
linked to:
Eoarchean Era
|
| hasRockRecord |
Acasta Gneiss Complex
ⓘ
Isua Greenstone Belt ⓘ Nuvvuagittuq Greenstone Belt ⓘ old rocks in Northwest Canada ⓘ old rocks in Western Australia ⓘ old rocks in Western Greenland ⓘ |
| importance |
constrains timing of origin of life
ⓘ
informs models of early Earth thermal evolution ⓘ records earliest preserved continental crust ⓘ |
| lowerBoundaryAge | 4000 Ma ⓘ |
| nameMeaning | dawn Archean ⓘ |
| oceanState | early hydrosphere already present ⓘ |
| partOf | Archean Eon ⓘ |
| positionInGeologicTimescale |
earliest era of the Archean Eon
ⓘ
second major eonothem of Earth history after the Hadean ⓘ |
| possibleEvidenceOf |
early biogenic carbon isotopic signatures
ⓘ
early microbial life ⓘ early photosynthetic activity ⓘ |
| precedes | Paleoarchean Era ⓘ |
| rank | era ⓘ |
| startTime |
4000 million years ago
ⓘ
about 4.0 billion years ago ⓘ |
| tectonics |
dominated by small protocontinents
ⓘ
early form of plate tectonics debated ⓘ |
| upperBoundaryAge | 3600 Ma ⓘ |
| usedIn |
International Commission on Stratigraphy timescale
ⓘ
linked to:
International Chronostratigraphic Chart
|
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Eoarchean Era Description of subject: The Eoarchean Era is an ancient division of Earth's early history marked by the formation of the first stable continental crust and some of the oldest known rocks and possible signs of early life.
Referenced by (5)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Eoarchean Era
linked to: Eoarchean Era