Volcano Cinder Cone — free printable diagram

What a cinder cone volcano diagram shows

A cinder cone is the smallest and simplest of the main volcano types. It is not built from lava flows at all, but from loose fragments — cinders, scoria and ash — thrown out of a single vent by gassy eruptions and falling back around it. The result is a small, strikingly steep and symmetrical cone with a bowl-shaped crater at the top.

Shape

Small, steep, symmetrical cone

Built from

Loose fragments — cinders, scoria and ash

Collective name for the fragments

Tephra

Eruption style

Gas-driven, explosive but small and often short-lived

Lava type

Usually basaltic

Crater

A bowl-shaped hollow at the summit

Size

The smallest of the main volcano types

Often found

On the flanks of larger volcanoes, or in clusters

• The building material is the whole point of this diagram. Fragments of frothy, gas-filled lava are blasted out, cool in the air and land around the vent, so the cone is a pile of loose rubble rather than a stack of solidified flows.
• Loose material can only pile so steeply before it slides, which is what sets both the cone's steep angle and its limited height. The slope is steeper than a shield volcano's but the volcano is far smaller.
• Many cinder cones are built in a single eruptive episode lasting weeks to a few years, and then never erupt again — unlike a composite volcano, which is constructed over many eruptions.
• Lava can still escape, but it usually leaks from the base of the cone rather than overflowing the crater, because the loose walls are too weak to hold a column of molten rock.
• The three types are best compared together: cinder cone — fragments, small, very steep; composite — layers of lava and ash, large and steep; shield — runny lava, very broad and gentle.
• Because they are made of unconsolidated material, cinder cones erode comparatively quickly, which is why old ones are far less distinct than old lava structures.