Diamictite is a poorly or non-sorted conglomerate

Conglomerate (geology)

A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

 or breccia

Breccia

Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....

 with a wide range of clasts, up to 25% of them gravel sized (greater than 2 cm). Diamictites are composed of coarse, angular to well rounded sedimentary clastic fragments, or other type of fragments (igneous and metamorphic rocks) supported by a typically argillaceous (clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

 sized) matrix

Matrix (geology)

The matrix or groundmass of rock is the finer grained mass of material in which larger grains, crystals or clasts are embedded.The matrix of an igneous rock consists of finer grained, often microscopic, crystals in which larger crystals are embedded. This porphyritic texture is indicative of...

.

The term was coined in 1960 by Flint and others as a purely descriptive term for poorly sorted and laminated rocks, avoiding any reference to a particular origin.

Diamictites are often interpreted mistakenly as having a glacial or ice sheet origin only (see Snowball Earth

Snowball Earth

The Snowball Earth hypothesis posits that the Earth's surface became entirely or nearly entirely frozen at least once, some time earlier than 650 Ma . Proponents of the hypothesis argue that it best explains sedimentary deposits generally regarded as of glacial origin at tropical...

), while in fact they can be produced by a wide range of different geological mechanisms. Possible origins include:

• glacial origin
  • meltwater flow deposition
  • unsorted moraine
    Moraine
    A moraine is any glacially formed accumulation of unconsolidated glacial debris which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have...
    
     glacial till
    Till
    thumb|right|Closeup of glacial till. Note that the larger grains in the till are completely surrounded by the matrix of finer material , and this characteristic, known as matrix support, is diagnostic of till....
    
    
  • basal melt-out
  • ice rafted sediments deposited by melting icebergs or disintegrating ice sheets (dropstone
    Dropstone
    Dropstones are isolated fragments of rock found within finer-grained water-deposited sedimentary rocks. They range in size from small pebbles to boulders...
    
    s)
• volcanic
  Volcano
  2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
  
   origin
  • lahar
    Lahar
    A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...
    
    s
  • lahar mass flows entering the ocean
• marine
  Marine (ocean)
  Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
  
   origin
  • debris flow
    Debris flow
    A debris flow is a fast moving, liquefied landslide of unconsolidated, saturated debris that looks like flowing concrete. It is differentiated from a mudflow in terms of the viscosity and textural properties of the flow. Flows can carry material ranging in size from clay to boulders, and may...
    
    
  • turbiditic
    Turbidite
    Turbidite geological formations have their origins in turbidity current deposits, which are deposits from a form of underwater avalanche that are responsible for distributing vast amounts of clastic sediment into the deep ocean.-The ideal turbidite sequence:...
    
     olistostrome
    Olistostrome
    The term olistostrome is derived from olio - a dish of many ingredients or stew; a mixture of heterogeneous elements; hodgepodge. and stroma - a bed covering...
    
    s
  • mixing of sediments by submarine landslides
• tectonic
  Tectonics
  Tectonics is a field of study within geology concerned generally with the structures within the lithosphere of the Earth and particularly with the forces and movements that have operated in a region to create these structures.Tectonics is concerned with the orogenies and tectonic development of...
  
   origin
  • fault gouge
• erosion
  Erosion
  Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
  
  al origin
  • regolith
    Regolith
    Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...
    
    , in the form of a debris flow
    Debris flow
    A debris flow is a fast moving, liquefied landslide of unconsolidated, saturated debris that looks like flowing concrete. It is differentiated from a mudflow in terms of the viscosity and textural properties of the flow. Flows can carry material ranging in size from clay to boulders, and may...
    
    
  • other mass wasting
    Mass wasting
    Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. Types of mass wasting include creep, slides, flows, topples, and falls, each with its own characteristic features, and taking place...
    
     events
• extraterrestrial
  Meteorite
  A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
  
   origin
  • impact breccia

The most common origin of diamictites is deposition by submarine mass flows like turbidites and olistostromes in tectonically active areas.

Further reading

• Deynoux, M., et al. (Editors) (2004) Earth's Glacial Record, Cambridge University Press, pp. 34–39 ISBN 0-521-54803-9

External links

• Illustration of a Canadian diamictite