• 13 structures
  • Checked October 2026

Convergent-Margin Orogen Diagram

A mountain belt cut through twice: at a subduction margin, then where two continents collide.

Convergent-Margin Orogen Diagram

Name Date

Tap any structure to read, rename or leave it out

1 2 3 4 5 6 7 8 9 10 11 12 13
More options

Write the name of each numbered structure.Answer key

  1. Trench
  2. Volcanic arc
  3. Accretionary wedge
  4. Forearc basin
  5. Subducting plate
  6. Overriding plate
  7. Plutons
  8. Suture
  9. Crustal root
  10. Fold-and-thrust belt
  11. Thrust faults
  12. Accreted terrane
  13. Metamorphic rocks

Drawn for this site on 2026-10-03 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a structure is answered.

Next step Next: one volcano cut in half

All 13 structures on the diagram

Show the list

Subduction margin 7

  1. Trench The deepest part of the sea floor. It forms where one plate bends down under another.
  2. Volcanic arc A belt of volcanoes above a subduction zone, on the overriding plate.
  3. Accretionary wedge Sediment scraped off the sinking plate and piled against the other plate.
  4. Forearc basin The low area between the accretionary wedge and the volcanic arc. Sediment collects in it.
  5. Subducting plate The plate that sinks beneath the other one.
  6. Overriding plate The plate that stays on top. The volcanic arc forms on it.
  7. Plutons Bodies of igneous rock that formed deep under the volcanic arc.

Collision 6

  1. Suture The zone where two landmasses have been joined.
  2. Crustal root Thick crust under the mountains. High mountains stand over thicker crust.
  3. Fold-and-thrust belt Rock layers folded and stacked along thrust faults. It lies at the edge of a mountain belt.
  4. Thrust faults Faults where the rock above is pushed up and over.
  5. Accreted terrane A block of crust that formed elsewhere. It was attached to the edge of the continent.
  6. Metamorphic rocks Rock changed by heat and pressure deep in the mountain belt.

How this list was compiled: Every name and definition checked on 2026-10-03 in two independent sources. (1) National Park Service, geology pages on convergent plate boundaries: Subduction Zones https://www.nps.gov/subjects/geology/plate-tectonics-subduction-zones.htm , Collisional Mountain Ranges https://www.nps.gov/subjects/geology/plate-tectonics-collisional-mountain-ranges.htm , Accreted Terranes https://www.nps.gov/subjects/geology/plate-tectonics-accreted-terranes.htm , and the NPS Glossary of Geologic Terms: subducting and overriding plate, accretionary wedge (accretionary prism in the glossary), forearc basin, volcanic arc, pluton and magmatic arc, suture, accreted terrane, crustal root, thrust fault, foreland fold-and-thrust belts, deep metamorphic rocks. (2) US Geological Survey, This Dynamic Earth, Understanding plate motions, https://pubs.usgs.gov/gip/dynamic/understanding.html : trenches, the subducting plate. (3) Wikipedia: Accretionary wedge, Forearc, Volcanic arc, Fold and thrust belt, Suture (geology), Continental collision, Orogeny, Foreland basin (https://en.wikipedia.org/wiki/Orogeny and the linked articles): trench, accretionary wedge or prism, forearc basin, volcanic arc and the plutonic rocks under it, subducting and overriding plate, suture, terranes, crustal root, thrust faults, fold and thrust belt, metamorphosed rocks of orogenic belts. 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

This convergent-margin orogen diagram cuts through a mountain belt twice: where an ocean plate sinks under a continent, and where two continents collide. Read the thirteen names, tap a structure for one line about it, then quiz yourself.

Read the full guide

The subduction margin

The subducting plate bends down at the trench and slides under the overriding plate. Sediment scraped off it piles up as the accretionary wedge. The forearc basin is the low area between the wedge and the volcanic arc, and plutons are the igneous bodies deep under the arc.

The collision

When an ocean closes, two continents collide and the crust thickens into a crustal root. The suture is the zone where the landmasses are joined, and an accreted terrane is a block attached along it. At the edge, layers are folded and stacked along thrust faults.

  • An orogen is a mountain belt. Orogeny is the event that builds it.

Questions and answers

What is a convergent-margin orogen?

An orogen is a mountain belt. A convergent-margin orogen is one built where two plates move toward each other: at a subduction zone, where one plate sinks beneath the other, or where two continents collide.

Where can I label the diagram of a convergent-margin orogen?

Here. Both cross-sections are this site's own drawings, and the names come from public geology sources. Press Quiz me to find each structure, or print the drawing blank and write the names in.

What is an accretionary wedge?

An accretionary wedge, or accretionary prism, is a wedge-shaped body of deformed rock. It is made of sediment scraped off the subducting plate and piled against the overriding plate beside the trench.

What is a suture in geology?

A suture is the zone where two continental landmasses, or two terranes, have been joined along a major fault zone. Suture zones mark the boundaries between different terranes.

More quizzes

Show 8 more

Browse Science Quizzes