stratigraphic unit
C1098
concept
A stratigraphic unit is a volume of rock or sediment defined and distinguished from adjacent material by its recognizable and mappable physical, chemical, or paleontological characteristics and its position in the geological record.
All labels observed (62)
| Label | Occurrences |
|---|---|
| stratigraphic unit canonical | 65 |
| sedimentary rock unit | 59 |
| chronostratigraphic unit | 30 |
| geologic group | 23 |
| rock unit | 12 |
| lithostratigraphic unit | 9 |
| sedimentary rock formation | 9 |
| geologic supergroup | 7 |
| lithostratigraphic group | 6 |
| sedimentary rock sequence | 6 |
| carbonate rock unit | 5 |
| tectonostratigraphic unit | 5 |
| Cretaceous stratigraphic unit | 4 |
| fossil-bearing stratigraphic unit | 4 |
| chronostratigraphic boundary | 3 |
| geologic unit | 3 |
| geological group | 3 |
| member (stratigraphy) | 3 |
| metamorphic rock sequence | 3 |
| coal-bearing formation | 2 |
| geological layer | 2 |
| igneous rock unit | 2 |
| subdivision of the Devonian Period | 2 |
| tectonostratigraphic zone | 2 |
| Devonian stratigraphic unit | 1 |
| Mesozoic stratigraphic unit | 1 |
| Ordovician stratigraphic unit | 1 |
| Permian rock unit | 1 |
| Permian stratigraphic unit | 1 |
| Pleistocene stratigraphic unit | 1 |
| Precambrian rock unit | 1 |
| Proterozoic rock unit | 1 |
| Silurian stratigraphic unit | 1 |
| Triassic rock unit | 1 |
| Triassic stratigraphic unit | 1 |
| ammonite zone | 1 |
| biostratigraphic subdivision | 1 |
| biostratigraphic zone | 1 |
| coal-bearing stratigraphic unit | 1 |
| crystalline limestone | 1 |
| epoch of the Quaternary Period | 1 |
| formal chronostratigraphic unit | 1 |
| fossil-based correlation unit | 1 |
| fossiliferous stratigraphic unit | 1 |
| geologic member | 1 |
| geologic series | 1 |
| geological horizon | 1 |
| limestone unit | 1 |
| mass extinction boundary | 1 |
| metamorphosed sedimentary rock sequence | 1 |
| rock sequence | 1 |
| rock succession | 1 |
| sedimentary rock succession | 1 |
| sedimentary sequence | 1 |
| stratigraphic group | 1 |
| stratigraphic level | 1 |
| stratigraphic sequence | 1 |
| stratigraphic subdivision | 1 |
| stratigraphic subgroup | 1 |
| stratigraphic succession | 1 |
| stratigraphic supergroup | 1 |
| subsurface geological unit | 1 |
Description generation (CDg)
The one-sentence description above was generated by prompting gpt-5.1 with the class name and this instruction.
Instruction
generate a one-sentence description for a given conceptual class. # Response Format Return only the sentence: "Description: [one-sentence description of the conceptional class]"
Input
Class: stratigraphic unit
Generated description
A stratigraphic unit is a volume of rock or sediment defined and distinguished from adjacent material by its recognizable and mappable physical, chemical, or paleontological characteristics and its position in the geological record.
Instances (241)
| Instance | Via concept surface |
|---|---|
| Niobrara Chalk | sedimentary rock unit |
| Cretaceous–Paleogene boundary | chronostratigraphic boundary |
|
Wealden Group of southern England
surface form:
Wealden Group
|
geologic group |
| Wealden Supergroup | geologic supergroup |
| Wessex Formation | sedimentary rock unit |
| Newark Supergroup | geologic supergroup |
| Bunter Sandstone | sedimentary rock unit |
| Keuper | lithostratigraphic unit |
| Paleocene | chronostratigraphic unit |
| Tiaojishan Formation | fossil-bearing stratigraphic unit |
| Yixian Formation | fossil-bearing stratigraphic unit |
|
Carnian age
surface form:
Carnian
|
chronostratigraphic unit |
| Anisian | chronostratigraphic unit |
| Jamesoni Zone | biostratigraphic zone |
| Ibex Zone | biostratigraphic subdivision |
| Davoei Zone | — |
| Margaritatus Zone | — |
| Spinatum Zone | chronostratigraphic unit |
| Holocene Baltic Sea stages | stratigraphic subdivision |
| Southern England Chalk Formation | Cretaceous stratigraphic unit |
| Hell Creek Formation | sedimentary rock unit |
| Shinarump Conglomerate | sedimentary rock unit |
| Shinarump Member | — |
| Monitor Butte Member | — |
| Sonsela Member | — |
| Owl Rock Member | — |
| Rock Point Member | — |
| Ediacara Member | — |
|
Nama Group, Namibia
surface form:
Nama Group
|
geologic group |
| Karoo Supergroup sediments | sedimentary rock sequence |
| Wenlock Epoch | chronostratigraphic unit |
| Absaroka Volcanic Supergroup | geologic unit |
| Hematite Ridge | sedimentary rock unit |
| Murray formation | sedimentary rock unit |
| Gaskiers Formation | rock unit |
| Borden Group | geologic group |
| Mississippian Series | geologic series |
| Salem Limestone | sedimentary rock unit |
| Tertiary System | chronostratigraphic unit |
| St. Louis Limestone | carbonate rock unit |
| Tuwaiq Mountain Limestone Formation | carbonate rock unit |
| Weald Clay | sedimentary rock unit |
| Hutchinson Salt Member deposits | subsurface geological unit |
| Rhyacian System | chronostratigraphic unit |
| Huronian Supergroup | geologic supergroup |
| Gowganda Formation | sedimentary rock unit |
| Gondwana Group | geologic group |
| Newark Basin volcanic sequence | igneous rock unit |
| Carbondale Formation | — |
| Spraberry Formation | — |