geologic formation
Natural rock structure
A geologic formation is a distinct body of rock with consistent characteristics—composition, age, or structure—that distinguishes it from surrounding rock.
Geologists use formations as basic units for mapping and describing Earth's crust: The sandstone formation dates to the Jurassic period.
In casual use, the term often refers to any striking natural rock feature: We hiked past unusual rock formations.
- AppalachiansEastern U.S. mountain chain
- igneousFormed from cooled magma
- PaleozoicEarly complex-life epoch
- unconformityGap in rock sequence
- erosionGradual wearing away
rock cycle · strata · deposition · sedimentary · fault · fault line · Himalayas · anticline · Rockies · metamorphic · basalt · granite · Andes · tectonic plate · continental drift · fold · volcanism · lava flow
- groundwateraquifer, aquifers, water table, recharge, confined aquifer
geologic formationbuilt environment
Human-created physical surroundings
infrastructure · building · skyscraper · dam · quarry
geologic, geological, geologically, geology, geologist, formation, formations, formed, forming