Givetian–Frasnian boundary
E540927
The Givetian–Frasnian boundary marks the internationally recognized stratigraphic transition between the Middle and Late Devonian periods, defined by specific fossil and sedimentary changes in the geologic record.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Frasnian stage | 1 |
| Givetian–Frasnian boundary canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T5631651 — 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: Givetian–Frasnian boundary Context triple: [Middle Devonian, endBoundary, Givetian–Frasnian boundary]
-
A.
Emsian–Eifelian boundary
The Emsian–Eifelian boundary marks the internationally recognized transition between the Early and Middle Devonian periods in the geologic timescale.
-
B.
Furongian
Furongian is the late epoch of the Cambrian Period, marking the final stage of early Paleozoic marine life diversification before the Ordovician.
-
C.
Kellwasser horizons
The Kellwasser horizons are distinctive black shale layers in Late Devonian marine sediments that mark one of the major extinction pulses during the Late Devonian mass extinction.
-
D.
Hettangian stage
The Hettangian stage is the earliest age of the Jurassic Period, marking the beginning of the Mesozoic era’s Jurassic system in the geologic time scale.
-
E.
Lochkovian Epoch
The Lochkovian Epoch is the earliest subdivision of the Devonian Period, marking a time of significant diversification in early fish and terrestrial ecosystems.
- 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: Givetian–Frasnian boundary Target entity description: The Givetian–Frasnian boundary marks the internationally recognized stratigraphic transition between the Middle and Late Devonian periods, defined by specific fossil and sedimentary changes in the geologic record.
-
A.
Emsian–Eifelian boundary
The Emsian–Eifelian boundary marks the internationally recognized transition between the Early and Middle Devonian periods in the geologic timescale.
-
B.
Furongian
Furongian is the late epoch of the Cambrian Period, marking the final stage of early Paleozoic marine life diversification before the Ordovician.
-
C.
Kellwasser horizons
The Kellwasser horizons are distinctive black shale layers in Late Devonian marine sediments that mark one of the major extinction pulses during the Late Devonian mass extinction.
-
D.
Hettangian stage
The Hettangian stage is the earliest age of the Jurassic Period, marking the beginning of the Mesozoic era’s Jurassic system in the geologic time scale.
-
E.
Lochkovian Epoch
The Lochkovian Epoch is the earliest subdivision of the Devonian Period, marking a time of significant diversification in early fish and terrestrial ecosystems.
- F. None of above. chosen
Statements (30)
| Predicate | Object |
|---|---|
| instanceOf |
Devonian boundary
ⓘ
chronostratigraphic boundary ⓘ stage boundary ⓘ |
| appliesTo | Devonian marine sedimentary successions ⓘ |
| belongsTo | Phanerozoic Eonothem NERFINISHED ⓘ |
| characterizedBy |
changes in marine faunas
ⓘ
changes in reef ecosystems ⓘ lithostratigraphic changes ⓘ |
| correspondsTo | transition from Middle to Late Devonian time ⓘ |
| definedBy |
biostratigraphic criteria
ⓘ
conodont biozones ⓘ fossil assemblage changes ⓘ sedimentary changes ⓘ |
| follows | Givetian Stage NERFINISHED ⓘ |
| hasRank | stage boundary within the Devonian ⓘ |
| hasStratigraphicSignificance | global correlation of Devonian stages ⓘ |
| isDefinedAt | specific stratotype section ⓘ |
| isReferenceFor | correlation of Middle and Late Devonian strata ⓘ |
| isWithin |
Devonian Period
NERFINISHED
ⓘ
Paleozoic Era NERFINISHED ⓘ |
| marksTransitionBetween |
Late Devonian
NERFINISHED
ⓘ
Middle Devonian NERFINISHED ⓘ |
| partOf | Devonian System NERFINISHED ⓘ |
| precedes | Frasnian Stage NERFINISHED ⓘ |
| recognizedAs | international stratotype boundary ⓘ |
| recognizedBy | International Commission on Stratigraphy NERFINISHED ⓘ |
| separates |
Frasnian Stage
NERFINISHED
ⓘ
Givetian Stage NERFINISHED ⓘ |
| usedIn |
global chronostratigraphic scale
ⓘ
global geologic time scale ⓘ |
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: Givetian–Frasnian boundary Description of subject: The Givetian–Frasnian boundary marks the internationally recognized stratigraphic transition between the Middle and Late Devonian periods, defined by specific fossil and sedimentary changes in the geologic record.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Frasnian stage