This page lists 31 geological features that start with J, from “Joint” to “John Day Fossil Beds”. They include glaciers, canyons, caves, volcanoes, mountain ranges, and deep ocean trenches. Together they show how ice, water, heat, and moving plates shape the planet. Geologists, travelers, students, and curious readers use features like these to study Earth’s history, plan trips, and understand natural hazards.
Geological features are natural formations in the Earth’s crust that were built or carved by physical processes over long periods of time. The “Jurassic Coast” in England is a good example, since its cliffs hold about 185 million years of history and the Jurassic period itself is named after the nearby “Jura Mountains”.
Below you’ll find the table with the feature name, region, characteristics, and a short description for each entry.
Feature: The name of each geological feature, listed alphabetically so you can quickly find a specific one or browse the full list from start to finish.
Region: The country, area, or ocean where you can find the feature, which helps you place it on a map or plan a visit.
Characteristics: A short label for the main type or trait of the feature, so you can see at a glance whether it is a glacier, cave, or volcano.
Description: A brief explanation of what the feature is, how it formed, and what makes it notable, giving you useful context without technical detail.
Geological features
| Feature | Region | Characteristics |
|---|---|---|
| Joint | Worldwide | Rock fracture with no movement |
| Jökulhlaup | Iceland | Glacial outburst flood |
| Jökulsárlón | Iceland | Glacial lagoon with icebergs |
| Jökulsárgljúfur Canyon | Iceland | River-carved canyon |
| Jurassic Coast | England | Coastal cliffs with fossils |
| Jura Mountains | France, Switzerland | Folded limestone mountain range |
| Jungfrau | Switzerland | Alpine peak, glaciated |
| Jotunheimen | Norway | Alpine range with glaciers |
| Jostedalsbreen | Norway | Largest mainland European glacier |
| Jakobshavn Glacier | Greenland | Fast-moving outlet glacier |
| Jordan Rift Valley | Middle East | Continental rift valley |
| Juan de Fuca Plate | Pacific Northwest | Small oceanic tectonic plate |
| Juan de Fuca Ridge | Northeast Pacific | Seafloor spreading ridge |
| Japan Trench | Northwest Pacific | Deep subduction trench |
| Java Trench | Indian Ocean | Subduction trench |
| Japanese Alps | Japan | Rugged mountain ranges |
| Jan Mayen Fracture Zone | North Atlantic | Oceanic fracture zone |
| Jenolan Caves | Australia | Limestone cave system |
| Jeita Grotto | Lebanon | Limestone caves with river |
| Jewel Cave | South Dakota, USA | Long limestone cave with calcite crystals |
| Jacob’s Well | Texas, USA | Karst spring and underwater cave |
| Jackson Hole | Wyoming, USA | Glacier-carved valley beside fault |
| Jebel Hafeet | UAE, Oman | Folded limestone mountain |
| Jabal Shams | Oman | Highest peak with deep canyon |
| Jebel Barkal | Sudan | Sandstone butte |
| Jebel Marra | Sudan | Volcanic massif with crater lakes |
| Jorullo | Mexico | Cinder cone volcano |
| Jemez Volcanic Field | New Mexico, USA | Volcanic field with caldera |
| Jade Dragon Snow Mountain | China | Glaciated limestone massif |
| Joggins Fossil Cliffs | Nova Scotia, Canada | Coastal cliffs with fossils |
| John Day Fossil Beds | Oregon, USA | Layered volcanic ash badlands |
Descriptions
Joint
A crack in rock where the two sides have not slid past each other. Joints form as rock cools, dries, or is stressed, and they guide how rock weathers and how groundwater flows.
Jökulhlaup
A sudden, massive flood released when meltwater trapped under or behind a glacier breaks free. Often triggered by volcanic activity, these floods can carve canyons and carry huge amounts of ice and sediment.
Jökulsárlón
A deep lake at the edge of Breiðamerkurjökull glacier where icebergs break off and drift toward the sea. It has grown quickly as the glacier has retreated.
Jökulsárgljúfur Canyon
A long, steep-walled canyon cut by glacial floods and the Jökulsá á Fjöllum river. It is home to horseshoe-shaped Ásbyrgi and the powerful Dettifoss waterfall.
Jurassic Coast
A stretch of the Dorset and East Devon coast where rock layers record about 185 million years of Earth’s history. It is known for fossils, sea stacks, and arches.
Jura Mountains
A curved range of limestone ridges and valleys north of the Alps. The Jurassic geological period takes its name from these mountains.
Jungfrau
A 4,158-meter peak in the Bernese Alps, partly covered by glaciers. It sits beside the Aletsch Glacier, the largest in the Alps.
Jotunheimen
A mountain region in southern Norway that holds the highest peaks in Northern Europe. Its jagged summits and valleys were shaped by ice.
Jostedalsbreen
An ice cap covering about 480 square kilometers, with many glacier arms that flow down into fjord valleys.
Jakobshavn Glacier
One of the fastest-flowing and most productive glaciers in the world, it sends huge numbers of icebergs into Disko Bay. It is closely studied for its role in sea-level rise.
Jordan Rift Valley
Part of the Great Rift Valley, this deep trough runs from the Sea of Galilee through the Dead Sea to the Gulf of Aqaba. It forms where two tectonic plates slide past each other.
Juan de Fuca Plate
A remnant oceanic plate sinking beneath North America at the Cascadia subduction zone. It is linked to the volcanoes of the Cascades and the risk of major earthquakes.
Juan de Fuca Ridge
An underwater ridge where new ocean crust forms as two plates pull apart. It hosts active hydrothermal vents.
Japan Trench
A deep ocean trench where the Pacific Plate dives beneath Japan. It is the source of major earthquakes, including the 2011 Tōhoku quake.
Java Trench
Also called the Sunda Trench, this is the deepest point in the Indian Ocean. It forms where the Indo-Australian Plate slides under the Sunda Plate.
Japanese Alps
Three high ranges on Honshu, the Northern, Central, and Southern Alps, with peaks above 3,000 meters. They were uplifted by plate collision and carved by past glaciers.
Jan Mayen Fracture Zone
A long seafloor fault that offsets the Mid-Atlantic Ridge near the volcanic island of Jan Mayen. It marks where sections of the ridge have shifted sideways.
Jenolan Caves
One of the oldest known open cave systems in the world, with large chambers and many cave formations in the Blue Mountains.
Jeita Grotto
Two linked limestone caves, with an underground river in the lower one. They are known for large stalactites and stalagmites.
Jewel Cave
One of the longest caves in the world, with many miles of passages lined with sparkling calcite crystals.
Jacob’s Well
A natural spring that feeds Cypress Creek through a vertical shaft in the limestone. The cave beneath it extends for a long way.
Jackson Hole
A broad mountain valley at the base of the Teton Range. It lies along the Teton Fault, which has lifted the mountains above the valley floor.
Jebel Hafeet
A rugged anticline of limestone rising from the desert plain near Al Ain. Its slopes contain fossils and ancient tombs.
Jabal Shams
The highest mountain in Oman, in the Al Hajar range. Nearby Wadi Ghul is often called the Grand Canyon of Arabia.
Jebel Barkal
A flat-topped sandstone outcrop rising about 100 meters from the desert near the Nile. It has long been regarded as a sacred site.
Jebel Marra
A volcanic mountain range in Darfur whose peak, Deriba Caldera, holds crater lakes. It forms a cooler, wetter area in the surrounding desert.
Jorullo
A volcano that rose from a farm field in 1759 and grew rapidly over several months. It is one of the best-recorded examples of a new volcano forming.
Jemez Volcanic Field
A large area of volcanic activity that includes the Valles Caldera. Hot springs and lava domes mark its past eruptions.
Jade Dragon Snow Mountain
A range of peaks in Yunnan, topped by 5,596-meter Shanzidou. It holds some of the southernmost glaciers in Eurasia.
Joggins Fossil Cliffs
Tall cliffs exposing Carboniferous rock layers, with fossilized trees and some of the earliest known reptile remains.
John Day Fossil Beds
Colorful hills of ancient volcanic ash and sediment. Fossils preserved here record about 50 million years of changes in life and climate.