A clastic dike is a seam of sedimentary material that fills a crack in and cuts across sedimentary strata or 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 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.
With phrasing typical of the early-century American geologist, Olaf P. Jenkins states, "It appears, then, that in every case fissures formed and then fragmental materials are dropped, washed, or pressed into them, from above, below, or from the sides. This action has taken place in open fissures; under water in fissures on the bed of the sea or other bodes of water; and also far below the surface of the earth in consolidated rocks. The filling from below has come about by pressure of some sort, in some cases undoubtedly hydrostatic."
Clastic dikes are found in sedimentary basin deposits worldwide. Formal geologic reports of clastic dikes began to emerge in the early 19th century.
Terms synonymous with clastic dike include: clastic intrusion, sandstone dike, fissure fill, soft-sediment deformation, fluid escape structure, seismite, injectite, liquefaction feature, neptunian dike, 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 earthquakes -
- An incredible variety of dikes is 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 flows -
- Sandstone dikes formed by downward injection are found along Black Dragon wash upstream of the famous petroglyphs area, San Rafael Swell, UT.
- Clastic dikes associated with impact craters -
- Sandstone dikes with cataclastically deformed sand grains, sourced in the Permian White Rim Sandstone, are found within Upheaval Dome, Canyonlands National Park, Utah, 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 domes -
- Clastic dike swarms associated with salt dome diapirism are reported from the Dead Sea region.
- Clastic dikes associated with glaciers -
- 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 Missoula flood deposits
Tens of thousands of unusual clastic dikes (1 mm—350 cm wide) in Pleistocene sediments of southeastern Washington may be related to loading by outburst floods. Other evidence suggests the dikes may be sediment-filled desiccation cracks. Cracks formed in flood-deposits Touchet Formation dried out, leaving deep, open cracks which subsequently filled with collapsed, windblown, or washed-in material over a long period of time. Some have suggested the dikes are fossil ice wedge casts or features related to the melting of buried ice. Cold-climate conditions (periglacial or nearly so) existed at the time of their formation. Earthquake shaking and liquefaction is invoked by others to explain the dikes (i.e., sand blows). The origin of the clastic dikes in the Columbia Basin is under debate.
Silt-, sand-, and gravel-filled dikes sourced in Touchet Beds (or Touchet-equivalent deposits of similar age and depositional history) intrude downward into older geologic units including the Pleistocene Clearwater Gravels in the Lewiston Basin, pre-late Wisconsin deposits in the Walla Walla Valley and Columbia Basin, Miocene—Pliocene Snipes Mountain Conglomerate at Granger, WA, Miocene—Pliocene Ringold Formation in the Pasco Basin, Miocene-Pliocene Ellensburg Formation at Ellensburg, WA (Craig's Hill), Miocene Columbia River Basalts at Gable Mountain, pre-late Wisconsin and basalt units in the Walla Walla Valley, Dalles Group in the Willow Creek Valley near Cecil, Oregon, and fine grained interbeds (Latah Fm-equivalent units) in Columbia River basalts in the Columbia Gorge below Wallula Gap.
Early reports describe the features in detail (Jenkins, 1925; Lupher, 1944; Brown and Brown, 1962; Newcomb, 1962). Additional details, data, and discussions are provided in later works (Alwin, 1970; Carson et al., 1978; Grolier and Bingham, 1978; Black, 1979; Cooley, 1996; Fecht et al., 1999; Spencer and Jaffee, 2002; Clement and Murray, 2007; Murray et al., 2007; Mayes et al., 2009).
- Richard J. Davies, R.J.; Huuse, M.; Hirst, P.; Cartwright, J.; Yang, Y., 2006, Giant clastic intrusions primed by silica diagenesis, Geology, 34, p. 917-920
- 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
- Darwin, C., 1833-1834, Geological observations on the volcanic islands and parts of South America visited during the voyage of the H.M.S. “Beagle” (2nd Edition), p. 438
- Hay, R., 1892, Sandstone dikes in northwestern Nebraska, GSA Bulletin, 3, p. 50-55
- Case, E.C.; 1895, On the mud and sand dikes of the White River Miocene, Ithaca, N.Y., American Geologist, 24, p. 248-254
- Cross, W., 1894, Intrusive sandstone dikes in granite, GSA Bulletin, 5, p. 225-230
- Crosby, W.O., 1897, Sandstone dikes accompanying the great fault of Ute Pass, Colorado, Essex Institute Bulletin, 27, p. 113-147
- Diller, J.S., 1890, Sandstone dikes, GSA Bulletin, 1, p. 411-442
- Newsom, J.F., 1903, Clastic dikes, Bulletin of the Geological Society of America, 14, p. 227-268
- Ransome, F.L., 1900, A peculiar clastic dike near Ouray, Colorado, and its associated deposit of silver ore, Transactions of the American Institute of Mineralogical Engineers, 30, p. 227-236
- Pavlow, A.P., 1896, On dikes of Oligocene sandstone in the Neocomian clasys fo the District of Altyr, in Russia, The Geological Magazine, New series, v. iii, p. 49-53
- Kirkby, J.W., 1860, On the occurrences of "sand pipes" in the magnesian limestones of Durham, The Geologist (London), p. 293-298, 329-336
- Prestwich, J., 1855, On the origin of the sand and gravel pipes in the chalk of the London Tertiary district, Quarterly(?) Journal of the Geological Society of London, v. ii, p. 64-84
- Mr. Strangeways, [dikes near Great Pulcovca near Saint Petersburg, Russia], 1821, Transaction of the Geological Society of London, v. V, p. 386, 407, 408 and Plates 25-28
- Cuvier & Brongniart, 1822 [sandstone pipes near Paris, France], Description geognostiques des Environs de Paris, p. 76, 134, 141
- Murchison, 1827, [quartz sandstone veins in grit near Kintradwell in Somersetshire], Transactions of the Geological Society of London, 2nd series, v. ii, p. 304
- Strickland, H.E., 1838, [calcareous sandstone dikes in Triassic shale at Ethie in Rossshire], Transactions of the Geological Society of London, v. V, 2nd series, p. 599-600
- Dana, J.D., 1838-1842, [wide sandstone dikes in bluffs near Astoria, OR observed during U.S. Navy/Charles Wilkes Exploring Expedition 1838-1842], Geology v. X, p. 654-656
- Buckland, 1839, Transactions of the British Association for 1839, p. 76
- Lyell, C., 1839, [sand pipes near Norwich, England], London and Edinburgh Philosophical Magazine, 3rd series, v. XV, p. 257
- Several more c. 1850 references to dikes in Newsom (1903)
- G. Neef, A clastic dike-sill assemblage in late Miocene (c. 6 Ma) strata, Annedale, Northern Wairarapa, New Zealand, New Zealand Journal of Geology & Geophysics, 1991, Vol. 34: 87—91 http://www.rsnz.org/publish/nzjgg/1991/11.php
- Peterson, C.D., 1997, Coseismic paleoliquefaction evidence in the central Cascadia margin, USA, Oregon Geology, 59, p. 51-74
- Audemard, F.A.; de Santis, F., 1991, Survey of liquefaction structures induced by recent moderate earthquakes, Bulletin of the International Association of Engineering Geology, 44, p. 5-16
- Ettensohn, F.R.; Rast, N.; Brett, C.E. (editors), Ancient Seismites, GSA Special Paper, 359
- Kevin G. Stewart, 2003, Paleoseismology http://www.unc.edu/~kgstewar/web_pages/paleoseismology.html
- Seilacher, A., 1969, Fault-graded beds interpreted as seismites, Sedimentology, 13, p. 15-159
- Mills, P.C., 1983, Genesis and diagnostic value of soft-sediment deformation structures – a review, Sedimentary Geology, 35, p. 83-104
- Groshong, R.H., 1988, Low-temperature deformation mechanism and their interpretation, GSA Bulletin, 100, p. 1329-1360
- Allen, C.R., 1975, Geological criteria for evaluating seismicity, GSA Bulletin, 86, p. 1041-1057
- Guiraud and Plaziet, 1993
- Obermeier, S.F., 1996b, Use of liquefaction-induced features for paleoseismic analysis - an overview of how seismic liquefaction features can be distinguished from other features and how their regional distribution and properties of source sediment can be used to infer the location and strength of Holocene paleo-earthquakes, Engineering Geology, 44, p. 1-46
- Greb, S.F.; Ettensohn, F.R.; Obermeier, S.F., 2002, Developing a classification scheme for seismites, GSA North-central & Southeastern Section Annual Meeting Abstracts with Programs
- Wheeler, R.L., 2002, Distinguishing seismic from nonseismic soft-sediment structures: Criteria from seismic-hazard analysis, in Ettensohn, F.R.; Rast, N.; Brett, C.E. (editors), Ancient Seismites, GSA Special Paper, 359, p. 1-11
- Obermeier, S.F.; Olson, S.M.; Green, R.A., 2005, Field occurrences of liquefaction-induced features: a primer for engineering geologic analysis of paleoseismic shaking, Engineering Geology, 76, p. 209-234
- Montenat, C.; Barrier, P.; d'Estevou, P.O.; Hibsch, C., 2007, Seismites: An attempt at critical analysis and classification, Sedimentary Geology, 196, p. 5-30
- Levi, T.; Weinberger, R.; Eyal, Y., in press 2010, A coupled fluid-fracture approach to propagation of clastic dikes during earthquakes, Tectonophysics
- Mashchak, M.S.; Ezersky, V.A., 1980, Clastic dikes of the Kara Crater Pai Khoi, Lunar and Planetary Sciences, 11, p. 680-682
- Mashchak, M.S.; Ezersky, V.A., 1982, Clastic dikes in the impactites and allogenic breccias of the Kara astrobleme (northeast slope of the Pai-Khoi Range) (article in Russian), Lithology and Economic Minerals, 1, p. 130-136
- Sturkell, E.F.F.; Ormo, J., 1997, Impact-related clastic injections in the marine Ordovician Lockne impact structure, central Sweden, Sedimentology, 44, p. 793-804
- Huntoon, P.W., 2000, Upheaval Dome, Canyonlands, Utah: Strain indicators that reveal an impact origin, in Sprinkel, D.A.; Chidsey, T.C.; Anderson, P.B. (editors), Geology of Utah's Parks and Monuments, Utah Geological Association Publication, 28, p. 1-10, revised 2002: http://www.utahgeology.org/Topical_papers_2003_UGA28.htm
- Kenkmann, T., 2003, Dike formation, cataclastic flow, and rock fluidization during impact cratering: an example from the Upheaval Dome structure, Earth and Planetary Science Letters, 214, p. 43-58
- Huntoon, P.W.; Shoemaker, E.M., 1995, Roberts Rift, Canyonlands, Utah, A natural hydraulic fracture caused by comet or asteroid, Ground Water, 33, p. 561-569
- Wittmann, A.; Kenkamnn, T.; Schmitt, R.T.; Hecht, L.; Stöffler, D., 2004, Impact-related dike breccia lithologies in the ICDP drill core Yaxcopoil-1, Chicxulub impact structure, Mexico, Meteorics & Planetary Science, 39, p. 931-954
- Hudgins, J.A.; Spray, J.G., 2006, Lunar impact-fluidized dikes: Evidence from Apollo 17 Station 7, Taurus-Littrow Valley, Lunar and Planetary Science, 37, p. 1176
- Marco, S.; Weinberger, R.; Agnon, A., 2002, Radial clastic dykes formed by a salt diapir in the Dead Sea Rift, Israel, Terra Nova, 14, p. 288-294
- Levi et al., 2006, Earthquake-induced clastic dikes detected by anisotropy of magnetic susceptibility, Geology, 34, p. 69–72
- Kruger, F.C., 1938, A clastic dike of glacial origin, American Journal of Science, 5, p. 305-307
- Goldthwait, J.W.; Goldthwait, L.; Goldthwait, R.P., 1951, Geology of New Hampshire, Part 1: Surficial Geology, New Hampshire State Planning and Development Commission, 44 pgs.
- Amark, M., 1986, Clastic dikes formed beneath an active glacier, Geologiska Föreningens i Stockholm Förhandlingar, 108, p. 13–20
- Dreimanis, A., 1992, Downward injected till wedges and upward injected till dikes, Sveriges Geologiska Undersökning, 4, p. 91-96
- Larsen, E.; Mangerud, J., 1992, Subglacially formed clastic dikes, Sveriges Geologisha Undersdhning, 81, p. 163-170
- Boulton, G.S.; Caban, P., 1995, Groundwater flow beneath ice sheets: Part II — Its impact on glacier tectonic structures and moraine formation, Quaternary Science Reviews, 14, p. 563-587
- Dreimanis, A,; Rappol, M., 1997, Late Wisconsinan sub-glacial clastic intrusive sheets along the Lake Erie bluffs, at Bradtville, Ontario, Canada, Sedimentary Geology, 111, p. 225-248
- Wicander, R.; Wood, G.D.; Dreimanis, A.; Rappol, M., 1997, Late Wisconsin sub-glacial intrusive sheets along Lake Eerie bluffs, at Bradtville, Ontario, Canada, Sedimentary Geology, 111, p. 225-248
- Van Der Meer, J.J.M.; Kjaer, K.H.; Kruger, J., 1999, Subglacial water-escape structures and till structures, Slettjokull, Iceland, Journal of Quaternary Research, 14, p. 191-205
- Rijsdijk, K.F.; Owen, G.; Warren, W.P.; McCarroll, D.; van der Meer, J.J.M., 1999, Clastic dykes in over-consolidated tills: Evidence for subglacial hydrofracturing at Killiney Bay, eastern Ireland, Sedimentary Geology, 129, p. 111-126
- Le Heron, D.P.; Etienne, J.L., 2005, A complex subglacial clastic dyke swarm, Solheimajokull, southern Iceland, Sedimentary Geology, 181, p. 25-37
- Gozdzik, J.; Van Loon, A.J., 2007, The origin of a giant downward directed clastic dyke in a kame (Belchatow mine, central Poland), Sedimentary Geology, 193, p. 71-79
- Crossen, K., 2009, Is till the only evidence of ice advance? What 15 year of post-surge retreat have revealed beneath Bering Glacier, Alaska, GSA Abstracts with Programs, Abstract #247-8
- Van Der Meer, J.J.M.; Kruger, J.; Rabassa, J.; Kilfeather, A.A., 2009, Under pressure: Clastic dykes in glacial settings, Quaternary Science Reviews, 28, p. 708-720
- Cross, W., 1894, Intrusive sandstone dikes in granite, GSA Bulletin, 5, p. 225-230
- Birman, J.H., 1952, Pleistocene clastic dikes in weathered granite-gneiss, Rhode Island, American Journal of Science, 250, p. 721-734
- Vitanage, P.W., 1954, Sandstone dikes in the South Platte Area, Colorado, Journal of Geology, 62, p. 493-500
- Harms, J.C., 1965, Sandstone dikes in relation to Laramide faults and stress distribution in the southern Front Range, Colorado, GSA Bulletin, 76
- Niell, A.W.; Leckey, E.H.; Pogue, K.R., 1997, Pleistocene dikes in Tertiary rocks - downward emplacement of Touchet Bed clastic dikes into co-seismic features, south-central Washington, GSA Abstracts with Programs, 29, p. 55
- Beacom, L.E.; Anderson, T.B.; Holdsworth, R.E., 1999, Using basement-hosted clastic dykes as syn-rift palaeostress indicators; an example from the basal Stoer Group, northwest Scotland, Geological Magazine, 136, p. 301-310
- Haluszczak, A., 2007, Dike-filled extensional structures in Cenozoic deposits of the Kleszczow Graben (Central Poland), Sedimentary Geology, 193, p. 81-92
- Monroe, J.N., 1950, Origin of the clastic dikes in the Rockwall area, Texas, Field & Laboratory, 18
- Chown and Gobeil, 1990, Clastic dykes of the Chibougamau Formation: distribution and origin, Canadian Journal of Earth Sciences, v.27, p. 1111-1114
- Dalrymple, R.W., 1979, Wave-induced liquefaction: A modern example from the Bay of Fundy, Sedimentology, 26, p. 835-844
- Alfaro, P.; Soria, M., 1998, Soft-sediment deformation structures induced by cyclic stress of storm waves in tempestites (Miocene, Guadalquivir Basin, Spain), Terra Nova, 10, p. 145-150
- Martel, A.T.; Gibling, M.R., 1993, Clastic dykes of the Devono-Carboniferous Horton Bluff Fm, Nova Scotia: Storm-related structures in shallow lakes, Sedimentary Geology, 87, p. 103-119
- Olson, S.M., 2007, Downward penetrating clastic dikes as indicators of tsunamis? GSA Southeastern Section Abstracts with Programs, 39, p. 25 (#14-5)
- Carson, R.J.; Pogue, K.R., 1996, Flood Basalts and Glacier Floods: Roadside geology of parts of Walla Walla, Franklin, and Columbia Counties, WA, Washington State Division of Geology and Earth Resources Information Circular 90
- Lupher, R.L., 1944, Clastic dikes of the Columbia Basin Region, Washington and Idaho, Geological Society of America Bulletin, 55, p. 1431-1462
- Othberg et al., 2003
- Garwood and Bush, 2005
- Webster et al., 1982, Late Cenozoic gravels in Hells Canyon and the Lewiston Basin, Washington and Oregon, in Bonnichsen and Breckenridge (editors), Cenozoic Geology of Idaho, Idaho Bureau of Mines and Geology Bulletin 26
- Spencer, P.K.; Jaffee, M.A., 2002, Pre-late Wisconsinan glacial outburst floods in southeastern Washington: The indirect record, Washington Geology, 30, p. 9-16
- Campbell, N.P., 1977, Geology of the Snipes Mountain area, Yakima County, Washington, Washington State Division of Geology & Earth Resources Open File Report, 77-8, 3 maps, 1:24,000 scale
- Smith, G.A.; Bjornstad, B.N.; Fecht, K.R., 1989, Neogene terrestrial sedimentation on and adjacent to the Columbia Plateau; Washington, Oregon, and Idaho, in Reidel, S.P.; Hooper, P.R. (editors), GSA Special Paper, 239, p. 187-198
- Reidel et al., 1994
- Brown, D.J.; Brown, R.E., 1962, Touchet clastic dikes in the Ringold Fm, Hanford Operations Report, HW-SA-2851, p. 1-11
- Mabry, J.J., 2000, Field Trip Guidebook to the Natural History of Kittitas County, Central Washington University, 74 pgs.
- Williams, M., 1991, Stratigraphic column of Craig's Hill, unpublished illustration, Central Washington University
- Fecht, K.R.; Bjornstad, B.N.; Horton, D.G.; Last, G.V.; Reidel, S.P. Lindsey, K.A., 1998, Clastic injection dikes of the Pasco Basin and vicinity, Bechtel Hanford Inc Report, BHI-01-01103
- 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. 57
- Cooley, S.W., 1996, Timing and emplacement of clastic dikes..., BA Thesis, Whitman College
- Pogue, 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