Dakota Formation
E274880
The Dakota Formation is a widespread Cretaceous sedimentary rock unit in North America, noted for its sandstone deposits that record the advance of the Western Interior Seaway and preserve abundant plant and dinosaur fossils.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Dakota Formation canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T2509901 — 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: Dakota Formation Context triple: [Morrison Formation, underlies, Dakota Formation]
-
A.
Morrison Formation
The Morrison Formation is a vast Late Jurassic sedimentary rock formation in the western United States renowned for its exceptionally rich assemblage of dinosaur fossils, including iconic sauropods and theropods.
-
B.
Sundance Formation
The Sundance Formation is a Middle to Late Jurassic marine sedimentary rock unit in the western United States, known for its shallow sea deposits that underlie the dinosaur-rich Morrison Formation.
-
C.
Hell Creek Formation
The Hell Creek Formation is a famous Late Cretaceous rock unit in North America renowned for its exceptionally rich dinosaur fossils, including iconic specimens like Tyrannosaurus rex and Triceratops.
-
D.
Kayenta Formation
The Kayenta Formation is an Early Jurassic sandstone and siltstone rock unit on the Colorado Plateau, renowned for its distinctive red cliffs and important dinosaur fossil trackways.
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E.
Chinle Formation
The Chinle Formation is a Late Triassic geologic formation in the southwestern United States, renowned for its colorful badlands, rich fossil beds, and extensive petrified wood deposits.
- 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: Dakota Formation Target entity description: The Dakota Formation is a widespread Cretaceous sedimentary rock unit in North America, noted for its sandstone deposits that record the advance of the Western Interior Seaway and preserve abundant plant and dinosaur fossils.
-
A.
Morrison Formation
The Morrison Formation is a vast Late Jurassic sedimentary rock formation in the western United States renowned for its exceptionally rich assemblage of dinosaur fossils, including iconic sauropods and theropods.
-
B.
Sundance Formation
The Sundance Formation is a Middle to Late Jurassic marine sedimentary rock unit in the western United States, known for its shallow sea deposits that underlie the dinosaur-rich Morrison Formation.
-
C.
Hell Creek Formation
The Hell Creek Formation is a famous Late Cretaceous rock unit in North America renowned for its exceptionally rich dinosaur fossils, including iconic specimens like Tyrannosaurus rex and Triceratops.
-
D.
Kayenta Formation
The Kayenta Formation is an Early Jurassic sandstone and siltstone rock unit on the Colorado Plateau, renowned for its distinctive red cliffs and important dinosaur fossil trackways.
-
E.
Chinle Formation
The Chinle Formation is a Late Triassic geologic formation in the southwestern United States, renowned for its colorful badlands, rich fossil beds, and extensive petrified wood deposits.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
geologic formation
ⓘ
sedimentary rock unit ⓘ |
| age |
Early Late Cretaceous
ⓘ
Late Early Cretaceous ⓘ |
| color | typically yellowish to brown ⓘ |
| contains | coal beds in some areas ⓘ |
| containsFossilsOf |
dinosaurs
ⓘ
fish ⓘ invertebrates ⓘ plants ⓘ |
| containsResource |
groundwater
ⓘ
petroleum reservoirs ⓘ uranium deposits ⓘ |
| continent | North America ⓘ |
| country |
Canada
ⓘ
United States of America ⓘ
surface form:
United States
|
| depositionalEnvironment |
deltaic
ⓘ
fluvial ⓘ nearshore marine ⓘ |
| fossilType |
dinosaur tracks
ⓘ
leaf impressions ⓘ pollen and spores ⓘ |
| geologicPeriod | Cretaceous ⓘ |
| geologicProvince | Western Interior Basin ⓘ |
| hasMember |
Juniata Member
ⓘ
Mesa Verde equivalent units ⓘ Tererro Member ⓘ |
| lithology |
mudstone
ⓘ
sandstone ⓘ siltstone ⓘ |
| namedAfter | Dakota Territory ⓘ |
| notedFor |
abundant plant impressions
ⓘ
high-quality sandstone aquifers ⓘ important dinosaur tracksites ⓘ |
| overlies |
Kiowa Formation
ⓘ
Morrison Formation ⓘ |
| records | advance of the Western Interior Seaway ⓘ |
| region |
Colorado Plateau
ⓘ
Great Plains ⓘ Rocky Mountain region ⓘ |
| researchField |
paleontology
ⓘ
sedimentology ⓘ stratigraphy ⓘ |
| stratigraphicUnitOf | Western Interior Seaway margin ⓘ |
| thickness | varies from a few meters to over 200 meters ⓘ |
| underlies |
Benton Group
ⓘ
Graneros Shale ⓘ |
| usedAs | building stone in some regions ⓘ |
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: Dakota Formation Description of subject: The Dakota Formation is a widespread Cretaceous sedimentary rock unit in North America, noted for its sandstone deposits that record the advance of the Western Interior Seaway and preserve abundant plant and dinosaur fossils.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.