stratigraphy
Geological layer science
Stratigraphy is the branch of geology that studies rock layers and their sequence.
Sedimentary rocks accumulate in strata over time, with older layers beneath younger ones—a principle that allows geologists to read Earth's history.
The term extends to archaeology, where soil layers reveal the chronological sequence of human occupation at a site.
Creation or arrangement
- bedrockSolid stone underground
- outcropSurfacing native stone
- faciesDiagnostic facial appearance
- correlationStatistical relationship measure
sequence · unconformity · cross-bedding · laminations · petrology · mineralogy · isotope · sedimentary
Waterborne earth particles
- clayMoldable earth for ceramics
- sandFine rock particles
- gravelLoose small rock fragments
- loessWind-deposited silt layer
alluvium · shale · marl · compaction · cementation · fluvial · marine · carbonate
Study of geological ages
- timelineOrdered display of events
- periodsSpans of time
- epochsDistinct historical stretches
- erasNamed spans of history
ages · dating · absolute · relative · sequence · time-scale · radiometric · carbon-14
Act of unearthing
- artifactHuman-made historical object
- provenanceRecord of ownership
- contextCircumstances shaping meaning
- middenHistorical domestic refuse pile
tell · feature · fill · cut · seriation · typology · disturbance · intrusion
Materials covering a mattress
- laminationBonding sheets together
- horizontalityParallel to the horizon
- superpositionCoexisting in multiple states
- profileSide-facing outline
section · horizon · bed · contact · transgression · regression
Preserved ancient organism traces
- trilobitesExtinct marine arthropods
- ammonitesExtinct coiled-shell cephalopods
- paleoecologyStudy of prehistoric ecosystems
- extinctionComplete vanishing of a species
zonation · assemblage · microfossils · biozone · correlation
formation
Creation or arrangement
correlation · sequence · unconformity · cross-bedding · laminations · petrology · mineralogy · isotope · sedimentary · basin
silt
Waterborne earth particles
loess · alluvium · shale · marl · compaction · cementation · fluvial · marine · carbonate · evaporite
geochronology
Study of geological ages
eras · ages · dating · absolute · relative · sequence · time-scale · radiometric · carbon-14 · potassium-argon
excavation
Act of unearthing
- artifactHuman-made historical object
- provenanceRecord of ownership
- contextCircumstances shaping meaning
midden · tell · feature · fill · cut · seriation · typology · disturbance · intrusion · phasing
bedding
Materials covering a mattress
- laminationBonding sheets together
- horizontalityParallel to the horizon
- superpositionCoexisting in multiple states
profile · section · horizon · bed · contact · transgression · regression
fossils
Preserved ancient organism traces
- trilobitesExtinct marine arthropods
- ammonitesExtinct coiled-shell cephalopods
- paleoecologyStudy of prehistoric ecosystems
extinction · zonation · assemblage · microfossils · biozone · correlation
stratigraphypetrology
Scientific study of rocks
mineralogy · crystallography · geochemistry · volcanology · tectonics