This page lists 38 geological features that start with D, from “Dacite” to “Dynamic Metamorphism”. The list covers rocks, landforms, faults, rivers, deserts, and mountains found on every continent. People use them to understand how the land around us formed, to find famous places to visit, and to learn about the materials we mine and build with.
Geological features are the natural structures and formations that shape the Earth’s surface and the rocks beneath it. They range from tiny mineral coatings to huge mountain ranges. The Deccan Traps in India, for example, are a vast lava plateau that may have helped end the age of the dinosaurs.
Below you’ll find the table with the geological feature, region, characteristics, and description for each entry.
Geological Feature: The name of each formation, rock, or process, listed alphabetically so you can quickly find the one you want to learn about.
Region: The place or places where you can find each feature, from a single country to landscapes that appear around the world.
Characteristics: A short set of key traits, such as rock type, shape, or setting, that help you recognize and compare features at a glance.
Description: A plain-language summary of how each feature forms, why it matters, and a notable example, so you get the main story without technical jargon.
Geological features
| Geological Feature | Region | Characteristics |
|---|---|---|
| Dacite | Worldwide volcanic arcs | Volcanic rock, silica-rich, light-colored |
| Dalradian Supergroup | Scotland and Ireland | Metamorphosed sedimentary rock sequence |
| Danakil Depression | Ethiopia, Eritrea and Djibouti | Below sea level, volcanic, salt flats |
| Dead Sea | Israel, Jordan and the West Bank | Lowest land elevation, hypersaline lake |
| Death Valley | California and Nevada, USA | Desert basin, below sea level, extreme heat |
| Debris Flow | Mountain regions worldwide | Fast-moving mix of water, soil and rock |
| Deccan Traps | Western India | Flood basalt, layered lava plateau |
| Deep-Sea Trench | Ocean basins worldwide | Narrow, extremely deep, subduction zone |
| Deflation Basin | Dry plains and deserts | Wind-eroded hollow, low depression |
| Delta | Major river mouths worldwide | Sediment deposit, fan-shaped, fertile land |
| Dendritic Drainage | River systems worldwide | Tree-like branching, uniform bedrock |
| Desert Pavement | Arid regions, including the American Southwest | Tightly packed stones, flat surface |
| Desert Varnish | Deserts worldwide | Dark mineral coating, found on rock surfaces |
| Devils Tower | Wyoming, USA | Igneous butte, columnar jointing |
| Diamond Pipe | South Africa, Russia, Canada and Botswana | Volcanic conduit, kimberlite, diamond source |
| Diapir | Salt basins and mountain belts worldwide | Rising dome, buoyant rock or salt |
| Diatomite | Worldwide, including California and Nevada | Soft sedimentary rock, made of fossil algae |
| Dike | Volcanic and mountain regions worldwide | Vertical sheet of igneous rock, cuts across layers |
| Diorite | Worldwide, in continental mountain belts | Coarse-grained igneous rock, speckled appearance |
| Dip-Slip Fault | Tectonic boundaries worldwide | Vertical movement, normal or reverse |
| Dissolved Cave | Karst regions worldwide | Limestone, water-carved chambers |
| Divergent Boundary | Mid-ocean ridges and rift valleys | Plates pulling apart, new crust formation |
| Dolerite | Worldwide, including Tasmania and Scotland | Dark intrusive rock, medium-grained |
| Dolina | Karst regions of Slovenia, the Balkans and elsewhere | Bowl-shaped depression, limestone terrain |
| Dolomite | Dolomites in Italy and worldwide | Carbonate rock, calcium magnesium composition |
| Dolomites | Northern Italy | Jagged mountain range, pale limestone peaks |
| Dome Mountain | Worldwide, including the Black Hills and Henry Mountains | Uplifted rock layers, rounded shape |
| Doline | Karst landscapes worldwide | Funnel or bowl-shaped, collapse or dissolution |
| Downwarp | Continental interiors and basins | Sagging crust, broad basin |
| Drainage Basin | Every continent | River catchment area, watershed |
| Dreikanter | Deserts and cold, windy regions | Wind-shaped stone, three faces |
| Drumlin | Glaciated regions, including Ireland, Canada and New York | Streamlined hill, glacial deposit |
| Dry Valley | Chalk and limestone regions, and Antarctica | Valley without a river, ancient water erosion |
| Dune | Deserts and coastlines worldwide | Wind-blown sand ridge, shifting |
| Dune Field | Sahara, Namib and Arabian deserts | Large sand area, dunes, erg |
| Dust Bowl Region | Southern Great Plains, USA | Eroded farmland, wind erosion |
| Dyke Swarm | Canada, Scotland, Iceland and Africa | Parallel igneous sheets, radiating pattern |
| Dynamic Metamorphism | Fault zones and mountain belts | Intense pressure, rock deformation |
Descriptions
Dacite
A fine-grained volcanic rock between andesite and rhyolite in composition. It forms thick, sticky lava domes and was a major component of the 1980 Mount St. Helens eruption.
Dalradian Supergroup
A thick belt of folded and metamorphosed rocks stretching across the Scottish Highlands and northern Ireland. It records the ancient seafloor that existed before the Caledonian mountain-building event.
Danakil Depression
One of the hottest and lowest places on Earth, sitting where three tectonic plates pull apart. It features salt plains, acidic hot springs and the active Erta Ale lava lake.
Dead Sea
A salt lake sitting about 430 meters below sea level, the lowest dry land on Earth. Its water is so salty that swimmers float effortlessly, and sinkholes regularly open along its shores.
Death Valley
A long, narrow basin containing the lowest point in North America at 282 feet below sea level. It holds the record for the hottest air temperature ever reliably measured on Earth.
Debris Flow
A rapid slurry of mud, rocks and water that races down steep slopes after heavy rain or snowmelt. It can travel at high speed and carry boulders far from their source.
Deccan Traps
A huge series of ancient lava flows covering much of western India. It formed around 66 million years ago, and its eruptions may have contributed to the extinction of the dinosaurs.
Deep-Sea Trench
A long, steep-sided canyon on the ocean floor formed where one tectonic plate slides beneath another. These are the deepest parts of the oceans, reaching more than 36,000 feet.
Deflation Basin
A shallow depression carved out when wind removes loose sand and silt from the ground. Some are only a few feet deep, while others stretch for miles.
Delta
A landform created where a river slows and drops its sediment as it enters a sea or lake. The Nile, Mississippi and Ganges deltas are famous examples.
Dendritic Drainage
A river pattern in which streams branch out like the limbs of a tree. It usually forms where the underlying rock erodes evenly in all directions.
Desert Pavement
A surface of closely fitted pebbles and rocks left behind when wind and water carry off finer material. It forms a natural armor that protects the soil below.
Desert Varnish
A thin, dark coating of manganese and iron minerals that builds up on exposed desert rocks over thousands of years. Ancient peoples often carved petroglyphs into it.
Devils Tower
A towering rock formation rising about 867 feet above the surrounding land. It formed from cooled magma, which cracked into tall, multi-sided columns.
Diamond Pipe
A carrot-shaped vertical vein of kimberlite rock that carries diamonds up from deep within the Earth. Its explosive eruptions bring the gems to the surface.
Diapir
A mass of lighter material, such as salt or magma, that pushes upward through denser overlying rock. Over time it can create domes and fold the layers above it.
Diatomite
A lightweight, chalky rock formed from the silica shells of microscopic algae called diatoms. It is widely used in filters and as a mild abrasive.
Dike
A wall-like sheet of rock formed when magma fills a crack and hardens, cutting through existing rock layers. Some stand out as natural walls after the surrounding rock erodes away.
Diorite
An intrusive igneous rock with a salt-and-pepper look, made mostly of light and dark minerals. Ancient civilizations used it for statues and tools.
Dip-Slip Fault
A fault in which the rock on either side moves up or down along the fault plane. Normal and reverse faults are the two main types.
Dissolved Cave
A cavern formed when slightly acidic groundwater slowly dissolves soluble rock such as limestone. Many contain stalactites and stalagmites.
Divergent Boundary
A place where two tectonic plates move away from each other. Magma rises to fill the gap, creating new crust, as seen along the Mid-Atlantic Ridge.
Dolerite
A dark, medium-grained igneous rock, chemically similar to basalt, that often forms sills and dikes. Its hardness makes it popular for road stone and building.
Dolina
Another name for a sinkhole or karst depression, formed where limestone dissolves or a cave roof collapses. The word comes from a Slavic term for valley.
Dolomite
A sedimentary rock and mineral made of calcium magnesium carbonate. It forms the pale, jagged peaks of the Italian Dolomites, a UNESCO World Heritage Site.
Dolomites
A mountain range in the Italian Alps known for sheer, pale rock towers that glow pink at sunset. The mountains began as ancient coral reefs in a tropical sea.
Dome Mountain
A rounded mountain formed when rising magma or salt pushes up the layers of rock above it. The Henry Mountains in Utah are a classic example.
Doline
A closed depression in the ground, formed when soluble rock dissolves or an underground cave collapses. Dolines often collect water and form small ponds.
Downwarp
A broad area where the Earth’s crust has bent downward, often forming a basin. Sediments collect in these low areas over millions of years.
Drainage Basin
The total land area from which rainfall and streams flow into a single river or lake. The Amazon basin is the largest in the world.
Dreikanter
A rock polished and shaped into three flat faces by wind-blown sand. The name is German for “three-edged.”
Drumlin
A smooth, oval hill shaped like an upside-down spoon, made of glacial sediment. Drumlins often occur in large groups called swarms.
Dry Valley
A valley carved by water but now lacking a surface stream. The McMurdo Dry Valleys of Antarctica are among the driest places on Earth.
Dune
A mound or ridge of sand shaped by the wind. Dunes can migrate over time and come in many forms, including crescent-shaped barchans and long linear dunes.
Dune Field
A broad area covered by many sand dunes, also called an erg. The Rub’ al Khali in Arabia is among the largest in the world.
Dust Bowl Region
A region where drought and poor farming practices stripped away topsoil in the 1930s. Massive dust storms blew the soil across much of North America.
Dyke Swarm
A large group of dikes that formed together from the same magma source. Some span hundreds of miles, including the Mackenzie dike swarm in Canada.
Dynamic Metamorphism
A type of rock change driven by powerful mechanical stress rather than heat. It crushes and shears rock along fault lines, producing rocks such as mylonite.