Upwarped mountainsA broad arch of crust pushed up from below. The Black Hills are an example.
Core of older rockOlder igneous and metamorphic rock, laid bare in the middle.
Tilted sedimentary layersSedimentary layers tilt away from the middle on every side.
UpliftThe crust is pushed up from below.
Folded mountains 4
Folded mountainsRock layers squeezed into folds. The Appalachians are an example.
AnticlineAn upfold: the layers arch upward.
SynclineA downfold: the layers sag into a trough.
CompressionThe crust is squeezed from both sides.
Fault-block mountains 5
Fault-block mountainsBlocks of crust raised along faults. The Basin and Range has many.
Normal faultThe block above the break has slid down.
HorstA raised block, bounded by normal faults.
GrabenA block that has dropped between two normal faults.
TensionThe crust is stretched and pulled apart.
Volcanic mountains 4
Volcanic mountainsA mountain built up by eruptions. Mount Fuji is an example.
VentThe opening where magma reaches the surface.
Layers of lava and ashThe cone is built of alternating layers of lava and ash.
MagmaMelted rock that rises from deep in the crust.
How this list was compiled: Every name and statement checked on 2026-10-03 in two independent sources. (1) National Park Service, Tectonic Landforms and Mountain Building, https://www.nps.gov/subjects/geology/tectonic-landforms.htm , with its page on the Valley and Ridge Province: fault-block mountains and normal faults, fold mountains made of anticlines and synclines, the folded strata of the Appalachian Mountains made by compression, volcanic mountains. (2) US Geological Survey, What is a fault and what are the different types?, https://www.usgs.gov/faqs/what-a-fault-and-what-are-different-types : a normal fault, in which the block above the fault moves down, in response to extension, as in the Basin and Range; a horst and graben diagram, the graben a down-dropped block made by extension, or pulling, of the crust. (3) US Geological Survey, Volcanoes: Principal Types of Volcanoes, https://pubs.usgs.gov/gip/volc/types.html : a composite volcano built of alternating layers of lava flows and ash, its central vent, its conduit and the magma that rises through it; Mount Fuji. (4) Tarbuck and Lutgens, Earth Science (1988) and its study guides, read by full-text search on archive.org, https://archive.org/details/earthscience00tarb : four kinds of mountain (folded, volcanic, fault-block and upwarped); upwarped mountains, made by a broad arching of the crust, with older igneous and metamorphic rock exposed in the center where the upwarped sedimentary beds have worn away; the Black Hills and the Adirondacks; folded mountains such as the Appalachians. (5) A. Sills, Earth Science the Easy Way (2003), read on archive.org, https://archive.org/details/earthscienceeasy00alan : domed or upwarped mountains, formed by a broad arching of the crust that leaves a core of igneous and metamorphic rock; fault-block mountains formed by tensional stresses; folded and volcanic mountains; compressional forces. (6) Wikipedia: Mountain, Mountain formation, Dome (geology), Black Hills, Adirondack Mountains, Fold mountains, Anticline, Syncline, Fault block, Horst (geology), Graben, Fault (geology), Stratovolcano, https://en.wikipedia.org/wiki/Mountain . (7) Continental Rifts (1985), read on archive.org, https://archive.org/details/continentalrifts0000unse : mountains (horsts) and valleys (grabens) bounded by normal faults. Licence: own work
The drawing: Drawn for this site on 2026-10-03 from plain geometry. Own original drawing; nothing is traced or copied. Licence: own work
How it works
These upwarped mountains labeled diagrams cut through a broad arch of crust with older rock laid bare in the middle. Three more views show how folded, fault-block and volcanic mountains are built.
Read the full guide
Pushed up or squeezed
Upwarped mountains form where the crust is arched upward. The layers on each side tilt away from a core of older rock. Folded mountains form where compression bends the layers into anticlines, which arch up, and synclines, which sag.
Pulled apart or built up
Fault-block mountains form where tension breaks the crust along normal faults: a horst stands high and a graben drops. Volcanic mountains are built of layers of lava and ash around a vent fed by magma.
Dome mountains counts as an answer for upwarped mountains.
Questions and answers
What are upwarped mountains?
Upwarped mountains, also called dome mountains, form when a broad area of crust is arched upward. Erosion wears away the top of the arch and lays bare older rock in the middle. The Black Hills and the Adirondacks are examples.
What are the four types of mountains?
Earth science courses often name four: upwarped or dome mountains, folded mountains, fault-block mountains and volcanic mountains. Each view of this page cuts through one of them.
What is the difference between an anticline and a syncline?
Both are folds in layered rock. In an anticline the layers arch upward. In a syncline they sag downward into a trough. Folded mountains are made of anticlines and synclines side by side.
What is the difference between a horst and a graben?
A horst is a block of crust that stands high between normal faults. A graben is a block that has dropped between them. They form side by side where the crust is stretched.