Geological Features
A world may be primarily composed of a single geological feature, or may be composed of many interconnected ones, each defining a new and unique region. Below you will find a list of common geological features roughly grouped by how they are formed or where you are likely to find them. If you are building a particular region, for example a coastal area, looking through that particular section will provide you with ideas you may wish to incorporate.
AEOLIAN
- Dry lake: a basin formerly containing a body of water
- Dunes: hills composed of loose sand
COASTAL
- Anchialine pool: a landlocked pool of water with a subterranean connection to the ocean
- Archipelago: a group of islands
- Atoll: a ring-shaped reef of coral
- Barrier island: an island formed by tidal action adjacent to a mainland coast
- Bay: a recessed body of water connected to a larger lake or ocean
- Beach: an area of loose sand or stone adjacent to a body of water
- Channel: a narrow and long body of water
- Cape: an area of land extending into a body of water
- Coastal cliff: a steep rock face rising from a body of water to the landmass above
- Coral reef: Growth and deposit of coral skeleton
- Cove: a small sheltered bay
- Estuary: an area of brackish area connected to the ocean in which rivers flow into
- Fjord: a narrow inlet with cliff sides
- Gulf: a large inlet
- Inlet: an area of water that projects into a landmass
- Island: an area of land surrounded by water
- Islet: a small island
- Isthmus: a narrow strip of land connecting two larger landmasses
- Lagoon: a shallow body of water separated from a sea or ocean by barrier islands or reefs
- Peninsula: an area of land bordered on three sides by water
- River delta: a deposition of silt at the mouth of a river
- Salt marsh: an area of brackish or saltwater that is regularly flooded
- Sea cave: a cave located along the coastline
- Shoal: a debris-covered landform that rises from the seabed to the near surface
- Shore: the area of land adjacent to a body of water
- Sound: a long, wide body of water connecting two larger bodies of water
- Straight: a narrow strip of water that connects to larger bodies of water
- Tidal marsh: a marsh created by tidal forces
- Tide pool: a pool of saltwater separated from the sea during low tide
- Volcanic island: an island formed by volcanic activity
SPELAEAN
- Aquifer: a body of permeable rock that contains groundwater
- Cave: a large underground chamber
- Cenote: a natural well or sinkhole
- Chamber: a large open space underground
- Chandelier: a cluster of ceiling crystals or other outgrowth
- Column: a vertical structure formed by the union of a stalagmite and a stalactite
- Dogtooth spar: large crystals that form near seasonal pools
- Flowstone: rock deposited from flowing water
- Frostwork: needle-like growths of crystal
- Grotto: an especially picturesque cavern
- Pit cave: a cave or cave system primarily composed of vertical shafts
- Ribbon stalactite: a stalactite resembling a ‘ribbon’ hanging from the ceiling
- Stalagmite: a mound or column that rises from a cave floor
- Stalactite: a tapering structure that hangs from a caves ceiling
- Subterranean river: an river or potion of river that resides underground
- Subterranean waterfall: an underground waterfall
- Underground lake: an underground lake
- Vertical shaft: a column of open space extending downwards
CRYOGENIC & GLACIAL
- Crevasse: a fissure or deep crack in an ice sheet
- Frost heave: an upwards swelling of soil caused by freezing ice under the ground
- Glacier: a slow moving mass or river of ice
- Ice sheet: a permanent layer of ice covering a landmass
- Ice shelf: a floating sheet of ice formed when an ice sheet or glacier flows onto the ocean surface
- Iceberg: a free floating mass of ice
- Permafrost plateau: a low, oval frost heave
- Pingo: a mound of ice covered in dirt
- Snow bridge: A layer of snow that covers a crevasse, rendering it unseen to navigators
- Subglacial lake: a body of water residing underneath a frozen glacier
- Subglacial river: a river of water running underneath a glacier
EROSION
- Badlands: an area of dry eroded land with little vegetation
- Box canyon: a short, narrow canyon enclosed on three sides
- Butte: an isolated hill with steep sides, usually smaller than a mesa
- Canyon: a deep gorge between cliffs
- Cliff: a steep rock face
- Gulch: a V-shaped valley
- Hoodoo: a thin spire of rock rising vertically from the landscape
- Mesa: an isolated flat topped hill with steep sides, larger than a butte but smaller than a plateau
- Plateau: an large, flat, elevated region of land
- Ravine: a gorge between cliffs similar to a canyon but smaller
- Scarp: a steep cliff or slope
- Valley: a low area between hills or mountains
MOUNTAINOUS
- Avalanche chute: a corridor where an avalanche has moved through
- Cirque: a bowl-shaped valley high on a mountain
- Couloir: a steep gorge in a mountainside
- Inselberg: a single mountain with no others nearby
- Mountain: a large rocky outcropping protruding from the earth
- Mountain range: a string of mountains
- Needle: a tall, thin, spire of rock
- Pass: a low point in a ridge which allows passage from one side to the other.
- Peak: any point which is higher than the surrounding points, may or may not be the mountain summit
- Ridge: a continuous elevated crest
- Spire: a tall and narrow rock formation
- Summit: the highest peak of a mountain
- Talus: collection of boulders at a base of a cliff
- Tarn: a small mountain lake
SUB-OCEANIC
- Abyssal plain: a flat area on the ocean floor
- Brine pool: an underwater pool or lake on the seafloor composed of high salt content
- Continental shelf: a relatively shallow submerged area of continent
- Hydrothermal vent (deep sea vent): a fissure on the seabed or chimney structure rising from it that releases geothermally heated water and minerals
- Mid-ocean ridge: an underwater mountain system
- Oceanic basin: a large underwater basin
- Oceanic plateau: a flat region that rises above the level of the surrounding seabed
- Oceanic ridge: an underwater mountain system
- Oceanic trench: a long and narrow depression in the seabed
- Seamount: an underwater mountain that does not reach the surface
- Submarine canyon: a steep valley in the seabed
- Submarine volcano: An underwater volcano which does not reach the surface
VOLCANIC
- Caldera: a large depression formed after the evacuation of an underlying magma chamber
- Crater lake: a lake formed in a volcanic crater or caldera
- Dormant volcano: a volcano which is temporarily inactive
- Extinct volcano: a volcano which will never be active again
- Geyser: a hot spring which intermittently boils the water within, sending a column of super-heated liquid and steam into the air
- Hot springs: a spring of naturally hot water
- Lava: term used for magma once it has reached the surface
- Magma: super-heated liquid rock
- Magma chamber: a pool of liquid rock underneath the earth
- Vent: an opening at the earth’s surface
- Volcano: a large vent through which lava is emitted
‘You know the fjords in Norway? I got a prize for creating those, you know.’
Slartibartfast, Hitchhiker’s Guide to the Galaxy