A clastic dike is a seam of

sedimentary Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

material that fills an open fracture in and cuts across

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

strata or layering in other rock types. Clastic dikes form rapidly by fluidized injection (mobilization of pressurized pore fluids) or passively by water, wind, and gravity (sediment swept into open cracks).

Diagenesis Diagenesis () is the process that describes physical and chemical changes in sediments first caused by water-rock interactions, microbial activity, and compaction after their deposition. Increased pressure and temperature only start to play a ...

may play a role in the formation of some dikes. Clastic dikes are commonly vertical or near-vertical. Centimeter-scale widths are common, but thicknesses range from millimetres to metres. Length is usually many times width. Clastic dikes are found in sedimentary basin deposits worldwide. Formal geologic reports of clastic dikes began to emerge in the early 19th century.Cross, W., 1894, Intrusive sandstone dikes in granite, GSA Bulletin, 5, p. 225-230 Terms synonymous with clastic dike include: ''clastic intrusion, sandstone dike, fissure fill, soft-sediment deformation, fluid escape structure, seismite, injectite, liquefaction feature, neptunian dike (passive fissure fills), paleoseismic indicator, pseudo ice wedge cast, sedimentary insertion, sheeted clastic dike, synsedimentary filling, tension fracture, hydraulic injection dike'', and ''tempestite''.

Environments of formation

Clastic dike environments include: *Clastic dikes associated with

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s – :A large variety of dikes are found in the geologic record. However, clastic dikes are typically produced by seismic disturbance and liquefaction of high water content sediments. Examples of this type are many. Clastic dikes are paleoseismic indicators in certain geologic settings. Several qualitative, field-based systems have been developed to help distinguish seismites from soft sediment deformation features formed by non-seismic processes. :Results from analytical modeling of clastic dike injection in soft rocks indicate propagation occurred at a rate of approximately 4 to 65 m/s at driving pressures of 1–2 MPa. Emplacement duration (<2 s) is similar to the speed with which acoustic energy (pressure waves) moves through partially lithified sedimentary rock. *Clastic dikes associated with

debris flow Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally ...

s - :Sandstone dikes formed by downward injection are found along Black Dragon wash upstream of the famous petroglyphs area,

San Rafael Swell The San Rafael Swell is a large geologic feature located in south-central Utah, United States about west of Green River. The San Rafael Swell, measuring approximately , consists of a giant dome-shaped anticline of sandstone, shale, and limesto ...

, Utah. *Clastic dikes associated with

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

s – :Sandstone dikes with cataclastically deformed sand grains, sourced in the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...

White Rim Sandstone, are found within

Upheaval Dome Upheaval Dome is an enigmatic geological structure in San Juan County, Utah, United States, that has been variously interpreted as a meteorite impact structure or a salt dome. The structure lies southwest of the city of Moab, Utah, in the Islan ...

, Canyonlands National Park,

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, at Roberts Rift, and elsewhere. Commonly, the fill is composed of angular grains, evidence that the injected material was lithified prior to impact and was crushed during injection into fractures (preexisting or impact-formed). *Clastic dikes associated with

salt dome A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered usin ...

s – :Clastic dike swarms associated with salt dome diapirism are reported from the Dead Sea region. *Clastic dikes associated with

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

s – :Sand injection features are reported to have formed under heavy loads and confining pressures beneath grounding glacial ice. *Clastic dikes in resistant bedrock – :Though unusual, a significant number of reports describe sedimentary material intruding fractured crystalline bedrock, usually within fault zones. Some of the articles referenced here describe lithified clastic dikes. *Clastic dikes in storm deposits – :Cyclic stresses from large waves can cause wet sediments to fluidize, forming various types of soft sediment deformation features including clastic dikes.

Clastic dikes in the Columbia Basin

Tens of thousands of unusual clastic dikes (1 mm—350 cm wide, up to 50 m deep) penetrate sedimentary and bedrock units in the Columbia Basin of

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

and

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyomi ...

. Their origin remains in question. The dikes may be related to loading by outburst floods. Other evidence suggests they are sediment-filled desiccation cracks (

mudcrack Mudcracks (also known as mud cracks, desiccation cracks or cracked mud) are sedimentary structures formed as muddy sediment dries and contracts.Jackson, J.A., 1997, ''Glossary of Geology'' (4th ed.), American Geological Institute, Alexandria, VA, ...

s). Some have suggested the dikes are

ice wedge An ice wedge is a crack in the ground formed by a narrow or thin piece of ice that measures up to 3–4 meters in length at ground level and extends downwards into the ground up to several meters. During the winter months, the water in the gr ...

casts or features related to the melting of buried ice. Earthquake shaking and liquefaction is invoked by others to explain the dikes (i.e., sand blows). The silt-, sand-, and gravel-filled dikes in the Columbia Basin are primarily sourced in the

Touchet Formation The Touchet Formation or Touchet beds consist of large quantities of gravel and fine sediment which overlay almost a thousand meters (several thousand feet) of volcanic basalt of the Columbia River Basalt Group in south-central Washington (U.S. ...

(or the Touchet-equivalent Willamette Silt) and intrude downward into older geologic units, including: *

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

hillslope colluvium with developed

caliche Caliche () is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions ...

horizons in the Umatilla Basin near

Alderdale, Washington Alderdale is an extinct town in Klickitat County, in the U.S. state of Washington. The GNIS The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural feature ...

landslide deposits along Hwy 14 in the Columbia Gorge (Umatilla Basin) * Pleistocene Clearwater Gravels in the Lewiston Basin * "Pre-late

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

" outburst flood and flood-related deposits (includes the "ancient cataclysmic flood deposits" of Allen et al., 2009) in the Walla Walla Valley/

Pasco Basin Pasco may refer to: People * Pasco (name) Places Australia * Pasco Island Group, Tasmania: ** Middle Pasco Islands ** North Pasco Island ** South Pasco Island Argentina * Pasco (Buenos Aires Metro), a station Peru * Cerro de Pasco, ...

Cooley, S.W.; Pidduck, B.K.; Pogue, K.R., 1995, Mechanism and timing of emplacement of clastic dikes in the Touchet Beds of the Walla Walla Valley, Geological Society of America Cordilleran Section Abstracts with Programs, 28, p. 57Cooley, S.W., 1996, Timing and emplacement of clastic dikes..., BA Thesis, Whitman CollegePogue, K.R., 1998, Earthquake-generated(?) structures in Missoula flood slackwater sediments (Touchet Beds) of southeastern Washington, Geological Society of America Abstracts with Programs, 30, p. A398 and Columbia Gorge * Post-basalt basin fill sediments (Dalles Group, etc.) exposed in tributary stream valleys downstream of

Wallula Gap Wallula Gap () is a large water gap of the Columbia River in the northwest United States in southeast Washington. It cuts through the Horse Heaven Hills basalt anticlines in the Columbia River Basin, just south of the confluence of the Wall ...

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Granger, Washington Granger is a city in Yakima County, Washington, United States. The population was 3,624 at the 2020 census. Although it was classified as a town in 2000, it has since been reclassified as a city. History Granger was founded in 1902 and named a ...

* Miocene-Pliocene

Ringold Formation The Ringold Formation is a geologic formation in Eastern Washington, United States. The formation consists of sediment laid down by the Columbia River following the flood basalt eruptions of the Columbia River Basalt Group, and reaches up to thi ...

in the Pasco Basin * Miocene-Pliocene Ellensburg Formation at Craig's Hill near

Ellensburg, Washington Ellensburg is a city in and the county seat of Kittitas County, Washington, United States. It is located just east of the Cascade Range near the junction of Interstate 90 and Interstate 82. The population was 18,666 at the 2020 census. and was ...

(outside Missoula flood track) * Miocene-Pliocene Ellensburg Formation at Foster Coulee (WDFW Foster Ck Wildlife Area) near Bridgeport, Washington * Miocene

Columbia River Basalt The Columbia River Basalt Group is the youngest, smallest and one of the best-preserved continental large igneous province, flood basalt province on Earth, covering over mainly eastern Oregon and Washington (state), Washington, western Idaho, a ...

(CRB) in the

Walla Walla Valley The Walla Walla River is a tributary of the Columbia River, joining the Columbia just above Wallula Gap in southeastern Washington in the United States. The river flows through Umatilla County, Oregon, and Walla Walla County, Washington. Its drai ...

and Pasco Basin at Gable Mountain * Latah Formation (interbeds in CRBs) west of

Finley, Washington Finley is a census-designated place (CDP) in Benton County, Washington, United States. The population was 6,012 at the 2010 United States Census, 2010 census. It is located to the southeast of the larger city of Kennewick, Washington, Kennewick. H ...

along Hwy 397 and elsewhere In 1925, Olaf P. Jenkins described the clastic dikes of eastern Washington state as follows:Jenkins, O.P., 1925, Clastic dikes of Eastern Washington and their geologic significance, American Journal of Science, 5th series, v. X, No. 57, p. 234-246

References

External links

Sandstone dikes photo gallery
{{DEFAULTSORT:Clastic Dike Sedimentary rocks Dikes (geology)