This page lists 39 geological features that start with N, running alphabetically from “Nappe” to “Norite”. They include mountains, volcanoes, faults, rock types, waterfalls, caves, and deltas from every part of the world. Some are ancient and hidden underground, while others are famous landmarks you can visit. People study them to understand earthquakes, find resources, plan travel, and learn how the planet has changed over time.
Geological features are the natural formations, structures, and materials that make up Earth’s surface and interior. They range from tiny mineral lumps to entire tectonic plates. The 1902 eruption of Mount Pelée in Martinique, which produced a “nuée ardente” that destroyed the town of Saint-Pierre, shows how powerful they can be.
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 structure, listed alphabetically so you can quickly find a specific item or browse the full range.
Region: Where each feature is found, from single countries to worldwide locations, which helps you plan a trip or compare places.
Characteristics: A short summary of what defines each feature, such as its shape, origin, or rock type, so you can grasp the basics at a glance.
Description: A brief explanation of how each feature forms, why it matters, and a notable fact or example to help you remember it.
Geological features
| Geological Feature | Region | Characteristics |
|---|---|---|
| Nappe | Alps, Himalayas, Scottish Highlands | Large sheet of rock moved far from its origin by thrust faulting |
| Natural Arch | Utah, USA; Worldwide | Rock opening formed by erosion |
| Natural Bridge | Virginia, USA; Worldwide | Arch carved by a flowing stream |
| Natural Levee | River floodplains worldwide | Raised bank built from deposited sediment |
| Nunatak | Greenland, Antarctica, Alaska | Rocky peak poking through ice |
| Neck (Volcanic Neck) | Colorado Plateau, Scotland, France | Hardened magma plug in an eroded volcano |
| Nuée Ardente | Volcanic regions, e.g. Martinique | Fast, glowing cloud of hot gas and ash |
| Névé | Alps, Himalayas, polar regions | Granular, partly compacted snow |
| Nickel-Iron Core | Earth’s center | Dense metallic interior |
| Niagara Escarpment | Ontario, New York, Michigan, Wisconsin | Long cliff of resistant dolostone |
| Niagara Falls | Ontario, Canada and New York, USA | Waterfall on an escarpment |
| Nile Delta | Egypt | Fan-shaped river delta |
| Niger Delta | Nigeria | Large, swampy river delta |
| Namib Desert Dunes | Namibia | Giant red sand dunes |
| Nazca Plate | Eastern Pacific, off South America | Oceanic tectonic plate |
| North American Plate | North America, western Atlantic | Large continental tectonic plate |
| Northern Rift (East African Rift) | East Africa | Spreading continental rift |
| Nyiragongo | Democratic Republic of the Congo | Stratovolcano with a lava lake |
| Nevado del Ruiz | Colombia | Ice-capped stratovolcano |
| Nevado Ojos del Salado | Chile and Argentina | Highest active volcano |
| Nevada Basin and Range | Nevada, USA | Parallel mountain ranges and valleys |
| Navajo Sandstone | Utah, Arizona, USA | Ancient wind-deposited sandstone |
| Nullarbor Plain | Southern Australia | Flat limestone plateau |
| Nahanni Karst | Northwest Territories, Canada | Cave and sinkhole landscape |
| Naica Crystal Cave | Chihuahua, Mexico | Cave of giant selenite crystals |
| Ngorongoro Crater | Tanzania | Large volcanic caldera |
| Nea Kameni | Santorini, Greece | Young volcanic island |
| Newfoundland Fault (Cabot Fault) | Newfoundland, Canada | Ancient strike-slip fault |
| New Madrid Seismic Zone | Missouri, Arkansas, Tennessee, USA | Intraplate earthquake zone |
| North Anatolian Fault | Turkey | Major strike-slip fault |
| Nankai Trough | Southern Japan | Subduction zone trench |
| Nazca Lines Plateau (Pampa) | Peru | Dry, stony desert plain |
| Neap Tide Flats (Tidal Flat) | Coastal regions worldwide | Muddy or sandy coastal area exposed at low tide |
| Nodule (Manganese Nodule) | Clarion-Clipperton Zone, Pacific Ocean floor | Metal-rich rounded rock on the seabed |
| Nodule (Chert and Flint) | Chalk and limestone formations worldwide | Hard, rounded mineral lumps |
| Normal Fault | Basin and Range, East African Rift | Fault where the hanging wall moves down |
| Nonconformity | Grand Canyon, USA; Worldwide | Sedimentary rocks sitting on older igneous or metamorphic rock |
| Nepheline Syenite | Ontario, Norway, Russia | Silica-poor igneous rock |
| Norite | Sudbury, Canada; South Africa | Dark igneous rock |
Descriptions
Nappe
A nappe is a huge slab of rock pushed many kilometers over other rock layers during mountain building. Nappes are common in the Alps and other collision zones.
Natural Arch
A natural arch is a rock span with an opening beneath it, carved by wind, water, or frost. Arches National Park in Utah holds more than 2,000 of them.
Natural Bridge
A natural bridge is a rock arch formed by a stream cutting through or beneath stone. Virginia’s Natural Bridge is about 215 feet high and was once crossed by a road.
Natural Levee
A natural levee is a low ridge along a river bank formed when floods drop coarse sediment. These ridges can slightly contain the river until they are breached.
Nunatak
A nunatak is an isolated mountain or ridge that sticks up through a glacier or ice sheet. The name comes from the Greenlandic word for lonely peak.
Neck (Volcanic Neck)
A volcanic neck is the solidified magma left in a volcano’s vent after the softer cone has eroded away. Shiprock in New Mexico is a famous example.
Nuée Ardente
A nuée ardente is a pyroclastic flow of superheated gas and volcanic debris that races down a volcano’s slope. The 1902 Mount Pelée eruption produced one that destroyed Saint-Pierre.
Névé
Névé is snow that has survived a summer and begun turning into glacier ice. It sits between fresh snow and solid glacial ice.
Nickel-Iron Core
Earth’s core is made mostly of iron and nickel. Its liquid outer part generates the magnetic field, while the inner part is solid.
Niagara Escarpment
The Niagara Escarpment is a ridge of hard rock arching around the Great Lakes region. Niagara Falls spills over it, and it extends for roughly 450 miles.
Niagara Falls
Niagara Falls is a group of waterfalls on the Niagara River that formed as glaciers retreated about 12,000 years ago. The falls have slowly eroded upstream ever since.
Nile Delta
The Nile Delta is a triangle of fertile land where the Nile River splits and meets the Mediterranean Sea. It is built from thousands of years of river silt.
Niger Delta
The Niger Delta is one of the biggest river deltas in the world, with mangroves and a maze of channels. It also holds major oil and gas reserves.
Namib Desert Dunes
The Namib Desert has some of the tallest dunes on Earth, with several near Sossusvlei topping 1,000 feet. Their orange color comes from iron-rich sand.
Nazca Plate
The Nazca Plate is a section of ocean crust that slides beneath South America. This subduction drives earthquakes and builds the Andes volcanoes.
North American Plate
The North American Plate carries most of North America and part of the Atlantic floor. It borders the Pacific Plate along the San Andreas Fault system.
Northern Rift (East African Rift)
Part of the East African Rift near Ethiopia, where Africa is slowly splitting apart. It features volcanoes, hot springs, and deep valleys.
Nyiragongo
Nyiragongo is a volcano with one of the world’s largest lava lakes in its crater. Its very fluid lava can drain quickly and flow fast down the slopes.
Nevado del Ruiz
Nevado del Ruiz is an active Andean volcano covered by glaciers. Its 1985 eruption melted ice into mudflows that buried the town of Armero.
Nevado Ojos del Salado
Nevado Ojos del Salado rises about 22,615 feet in the Andes and is the tallest volcano on Earth. It sits in one of the driest regions in the world.
Nevada Basin and Range
Nevada sits in the Basin and Range Province, where the crust has stretched and cracked. This produced dozens of north-south mountain ridges separated by flat valleys.
Navajo Sandstone
Navajo Sandstone is a thick layer of cross-bedded sandstone formed from Jurassic desert dunes. It forms the cliffs of Zion National Park.
Nullarbor Plain
The Nullarbor Plain is a huge, treeless limestone expanse along Australia’s southern coast. It contains many caves and sinkholes beneath the surface.
Nahanni Karst
The Nahanni region has some of the most developed northern karst terrain in the world. Its canyons, tufa mounds, and caves are protected in Nahanni National Park.
Naica Crystal Cave
Naica’s Cave of the Crystals holds gypsum beams up to about 36 feet long. The cave is extremely hot and humid, and exploring it requires special gear.
Ngorongoro Crater
Ngorongoro is a collapsed volcano whose floor, roughly 100 square miles wide, hosts abundant wildlife. It is among the biggest unbroken calderas in the world.
Nea Kameni
Nea Kameni is a small island that rose in the flooded Santorini caldera. It has grown through eruptions since 1707 and still shows volcanic activity.
Newfoundland Fault (Cabot Fault)
The Cabot Fault is an old fault running through Atlantic Canada, tied to the collision of ancient continents. It shaped the landscape and rock belts of the region.
New Madrid Seismic Zone
The New Madrid Seismic Zone produced several powerful earthquakes in 1811 and 1812. It lies far from any plate boundary, which makes it unusual.
North Anatolian Fault
The North Anatolian Fault stretches for about 750 miles across northern Turkey. A series of large earthquakes has moved westward along it since 1939.
Nankai Trough
The Nankai Trough is an undersea trench where the Philippine Sea Plate dives beneath Japan. It has produced repeated large earthquakes and tsunamis.
Nazca Lines Plateau (Pampa)
The Nazca Pampa is a flat, arid plain whose dark surface stones cover pale ground. Its stable, dry climate helped preserve ancient geoglyphs.
Neap Tide Flats (Tidal Flat)
Tidal flats are broad intertidal areas of sand and mud revealed as water recedes. They are rich habitats for birds and shellfish.
Nodule (Manganese Nodule)
Manganese nodules are potato-sized lumps on the deep sea floor that build up slowly around a core. They contain manganese, nickel, copper, and cobalt.
Nodule (Chert and Flint)
Flint and chert nodules are irregular lumps of silica found inside chalk and limestone. Early humans used them to make tools.
Normal Fault
A normal fault forms when the crust is stretched and one block slips downward relative to the other. These faults commonly create valleys and steep mountain fronts.
Nonconformity
A nonconformity is a gap in the geologic record where sedimentary layers rest on eroded crystalline rock. It marks a long period of uplift and erosion.
Nepheline Syenite
Nepheline syenite is a coarse-grained rock rich in feldspar-like minerals but low in quartz. It is used in glass and ceramics.
Norite
Norite is a coarse-grained rock in the gabbro family, made mostly of plagioclase and orthopyroxene. It is often associated with layered intrusions.