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Gunung Kelud (Kelut)

Glossary of Kelud-ian Terms!

Mt. Kelud
Crater Lake
Chemical Composition
A Quick History Lesson
Cool Facts!

The key terminology from the web site can be found on this page! Here you’ll find more detail on most of the important terms associated with Gunung Kelud!

Gunung:  the Indonesian word for Mount (title) or mountain (noun).[i]

Composite volcano (or stratovolcano):  a type of volcano that contains alternating layers of regular lava flow and pyroclastic materials; see the link on the left for stratovolcanoes![ii]

Crater lake:  water builds up in the basin-like depression (crater) at the summit of a volcano; see the link on the left for crater lake![iii]

Lahar:  a flow of mud and debris from the eruption and overflow of a crater lake; see the link on the left for lahar![iv]

Pyroclastic flows:  As we know from Geology 1020, pyroclastic flows are explosive eruptions that blow ash and minerals into the air. The minerals are formed from early crystallization in the magma (Bowen’s reaction series). When this  mixture of ash and minerals settles, it makes a layer on the outer dome of the volcano, making a pyroclastic layer that is characteristic of stratovolcanoes!

Subduction zone:  As we learned in Geology 1020, a subduction zone occurs at either an ocean-ocean or ocean-continent convergent plate boundary. Whichever plate is less dense will subduct under the other. Eg, oceanic crust will subduct under continental crust because is much less dense. Crust subducts due to either the ‘cold slab’ or ‘hot arc’ phenomenon.

Silicic magma:  Magma that contains from 60-75% SiO2, is rich in silica and aluminum and has a relatively low temperature, making it much more viscous and explosive.

Basaltic magma:  Basaltic magmas only contain about 50% magma, are rich in magnesium and iron and have very high temperature, making them very fluid.

Convergent Plate Boundary:  Convergent plate boundaries occur when two plates collide together; this process occurs due to compressional forces that could be either exo- or endogenic.



[ii] Source: Plummer, et al. 2007. Physical Geology and the Environment, 2nd Canadian Edition. Boston: McGraw-Hill Ryerson.

[iii] Source: Bernard, A. 2000. Geochemistry of the crater lake of Kelud volcano, Indonesia. Retrieved January 20 2008, from Geobase (Elsevier Engineering Village).

[iv] Thouret, J.C. et al. 1998. Origin, characteristics, and behaviour of lahars following the 1990 eruption of Kelud volcano, eastern Java (Indonesia). Bull. Volcanol. 59, p. 460-480. Retrieved January 20 2008, from Geobase (Elsevier Engineering Village).

by Victoria Gauthier (0330250)
Geology 1020
January 2008