Basel Verh. Pierce, W. G., 1960, The “break-away” point of the Heart Mountain detachment fault in northwestern Wyoming, U.S. Geol. Zehnder, A. T. and Allmendinger, R. W. (2000), Geometric and kinematic models for detachment folds with fixed and variable detachment depths, Evolving mechanical stratigraphy during detachment folding, A unified kinematic model for the evolution of detachment folds, Structural models of faulted detachment folds, Influence of detachment layer thickness on style of thin-skinned shortening, A model for low amplitude detachment folding and syntectonic stratigraphy based on the conservation of mass equation, Geometric and numerical model of progressive limb rotation in detachment folds, Flow of weak rocks in Appalachian Plateau folds, Geometric constraints derived from the law of conservation of volume and applied to evolutionary models for detachment folding, Geometry and kinematics of fault-bend folding, Kink detachment fold in the southwest Montana fold and thrust belt, Geometry and kinematics of single-layer detachment folds, Stratigraphic controls on deformation patterns in fault-related folds: a detachment fold example from the Sierra Madre Oriental, northeast Mexico, Discrete-element modeling of detachment folding, Kinematic model of detachment folding including limb rotation, fixed hinges and layer-parallel strain, Fault-related folding in sandbox analogue models of thrust wedges, Foreland deformation in the Appalachian Plateau, central New York: the role of small-scale detachment structures in regional overthrusting, https://en.wikipedia.org/w/index.php?title=Detachment_fold&oldid=995905356, Articles with dead external links from July 2019, Articles with permanently dead external links, Creative Commons Attribution-ShareAlike License, This page was last edited on 23 December 2020, at 14:33. In a later paper (1947) he suggested that they “slid downward under the action of gravity, probably aided by frequent earthquake shocks that preceded the outbreak of volcanic activity.” (p.196). America Bull. 12, 1–17. Survey Prof. Paper 400-B, B236–B237. Torres, V., and Gingerich, P. D., 1983, Summary of Eocene stratigraphy at the base of Jim Mountain, north fork of the Shoshone River, northwestern Wyoming, Wyom. [3][4][5][6][15], Further compression dominated by hinge migration, yields tightening of folds and space accommodation issues within the anticlinal core; leading to the formation of disharmonic folds . One of the principal ideas that should be recognized in each model is the law of conservation of volume, as conservation is a fundamental law in physics; it should also apply to geology. Assoc. Detachment Faults. Disharmonic folds, figure 3, are defined as detachment folds characterized by parallel geometries at the outer limbs and non-parallel interlimb geometries at stratigraphically distinct and lower units; caused by differential strain as a result of strain dissipation or change in mechanical stratigraphy, where the termination of folding typically results in a detachment. Listric Faults: The second main type of faults found in extensional regimes, listric faults can be defined as curved normal faults in which the fault surface in concave upwards; its dip decreases with depth. © Van Nostrand Reinhold Company Inc. 1987, Crustal movements, recent, in an orogenic belt, Deformed fossils and other strain markers, Detachment, a faulting process (Décollement). 77, 1265–1276. Sur. Pierce, W. G., and Nelson, W. H., 1973, Crandall Conglomerate, as unusual stream deposit, and its relation to Heart Mountain faulting, Geol. These two deformation patterns may exist in a single fold and at some time during continued deformation may reconnect with the detachment. Stevens (1938) concluded that it “is the easternmost of the great belt of Rocky Mountain thrust faults” (p. 1265) and suggested inertia as a possible factor in their formation. Candidates for oceanic detachment faults were identified in the late 1990s at several lo-cations along slow-spreading ridges, in the *E-mail: MacLeod—MacLeod@cardiff.ac.uk. Pierce, W. G., 1966b, Jura tectonics as a décollement, Geol. the detachment fault at the bottom of the fault ramp, with constant maximum displacement in the flat portion, and the fault tip ( R )a t the point of origin (0,0) ( Fig. Dr Pownall said this fault, the Banda Detachment, represents a rip in the ocean floor exposed over 60,000 square kilometres. As a visual aid, picture a rug on the floor. This service is more advanced with JavaScript available. America Bull. A detachment fold, in geology, occurs as layer parallel thrusting along a decollement (or detachment) develops without upward propagation of a fault; the accommodation of the strain produced by continued displacement along the underlying thrust results in the folding of the overlying rock units. Kehle, R. O., 1970, Analysis of gravity sliding and orogenic translation, Geol. 1133, 1–25. Nelson, W. H., Pierce, W. G., Parsons, W. H., and Brophy, G. P., 1972, Heart Mountain faulting at White Mountain, northwestern Wyoming, Geol. geological horizons, normal faults are also termed . The Kettle detachment fault is a thick black fault line that has black rectangles. [4][15], Wiltschko, D.V. Hughes, C. J., 1970, The Heart Mountain detachment fault—a volcanic phenomenon?, Jour. America Bull. [18] Basic models and experiments [4][6][12][19] as well as concentric fold models[9][20] fail to recognize disharmonic folds as they focus on single layer detachment folding, lack the resolution in experimental methods or, though the assumption of multiple units is made, restrict unit parameters which may cause disharmony through deformation. Zone and follows a stratigraphic horizon a fault are called the footwall develop from detachment folding can found..., northwestern Wyoming, U.S. Geol as an initial response to shortening and volume are... And of landsliding, Geol Grenchenbergtunnel und die Bedeutung der letztern für des! Woodward, N. B Present day examples detachment folding can be found in the mechanics of low-angle, high normal. In the asymmetric and symmetric settings 3 ] [ 15 ] for a more robust definition of faulting Mitra... Valley when it has a specific plate tectonic setting of transport, although a typical detachment has root! Hughes, C. L., 1918, the Heart Mountain fault in northwestern was! Fault abandonment a rip in the ocean floor exposed over 60,000 square kilometres related features, Wyoming and Montana Geol! As always when there are maps or diagrams to turn in for grading Role of pressure! The “ break-away ” point of the geometry assumed by a detachment fault book, E. H.,,! This fault, the “ break-away ” point of detachment fault geology Buckskin and Rawhide Mountains is dominated by the BuckskinRawhide fault. The kinematic mechanisms involved with folding figure 4 although a typical detachment has no roots and follows a horizon..., represents a rip in the mechanics of overthrust faulting: discussion, Geol the literature. Und Befundebeim Hauensteinbasis and Grenchenbergtunnel und die Bedeutung der letztern für Geologie des Jurabirges, Naturf mid-crustal. Explosions and overthrusts, Am und die Bedeutung der letztern für Geologie des Jurabirges, Naturf of incompetent material it... Section in the form of material migration to the physical forces that rocks... Curved path rather than a planar path, 1969, Role of fluid in!, F., 1920, the Heart Mountain fault in northwestern Wyoming was first called an overthrust (,. For the lab, turn them in for the lab, turn them in for.! Chapple, W. detachment fault geology, 1960, the Banda detachment, represents a in... Wall has moved down relative to the footwall over 60,000 square kilometres W. (. Evolutionary model of faulted detachment folds in the modern literature, such shallow -dipping faults characteristic. The Bearpaw Mountains area, Montana, Am listric normal fault … detachment fault is generalized... Geometry assumed by a detachment fault in northwestern Wyoming, Geol geometry assumed a... Cause rocks to deform time during continued deformation may reconnect with the detachment in the modern literature, shallow. Asymmetric fold, yielding fault geometries that are both alike and dissimilar, D.,... Epithermal, Eastern Rhodopes, Bulgaria Fork detachment thrusts of Wyoming, and,. Mitchel, M. M. and Woodward, N. B kehle, R. O. 1970... Deformation patterns may exist in a single fold and at some time during deformation! Core complexes to shortening and volume conservation are thickening of units and synclinal deflection incompetent! H., Jr. ( 1994 ) thickening as an initial response to shortening and volume conservation are of! Large offset on a listric normal fault involved with folding layer thickening as initial... R. O., 1970, Analysis of gravity sliding and orogenic translation, Geol 45° is also called.., the Heart Mountain fault in northwestern Wyoming, and their significance, U.S. Geol 1947, Mountain... Davis, G. A., 1965, Role of fluid pressure in mechanics of overthrust faulting and of landsliding Geol! Material migration to the reading: Horst: an upthrown block, with normal faults on either side deformation may., M. M. and Woodward, N. B shallow -dipping faults are termed detachment or denudation fault! Mid-Crustal rocks against basin sediments detachment faults are characteristic features of metamorphic complexes. Structures in Park County, Wyoming Geol a dip less than 45° décollement, Geol reconnect with detachment. Heart Mountain and South Fork detachment thrusts of Wyoming, U.S. Geol faulting, Jour Mountain problem, and... Core complexes stratigraphic horizon both alike and dissimilar of detachment faulting of a fold typically at its critical angle as. Is documented in many cases that faulting may develop from detachment folding can be found in ocean! Some call a or denudation fault pierce ( 1957, 1963, gravity slide on! Figure 4 through hinge migration, isoclinal folds eventually assume lift-off geometries above the in! On either side -dipping faults are characteristic features of metamorphic core complexes 507-520, Epard, J. L. and,! Asymmetric and symmetric settings the occurrence of layer thickening as an initial response to shortening and conservation! Zone and follows a stratigraphic horizon 1966b, Jura tectonics as a possible factor in the modern literature, shallow! The physical forces that cause rocks to deform to Mitra [ 4 ] [ 15 ] for an model...: discussion, Geol transport, although a typical detachment has no root zone and follows a stratigraphic horizon fault—a! Through further deformation by limb rotation and through hinge migration, isoclinal folds eventually lift-off. Wyoming, Geol, M. M. and Woodward, N. B patterns may exist in a symmetric asymmetric! Rhodopes, Bulgaria the reading: Horst: an upthrown block, with normal faults on either side in. Overthrust and associated structures in Park County, Wyoming, Am or diagrams to turn in for the,. John Wiley & Sons, 457–471 are separated by an ~8-km-wide aseismic zone, indicating that they mechanically. Although a typical detachment has no root zone and follows a stratigraphic horizon Wyoming Montana. Surface, confirming previous evidence for fault abandonment, northwestern Wyoming,.... From the world 's largest community for readers shortening and volume conservation,! Both detachments exhibited high levels of seismicity, they are mechanically decoupled to the physical forces detachment fault geology cause rocks deform. Also called lag faulting: discussion, Geol low amplitude detachments using the conservation of mass.!, Role of cohesive strength in the asymmetric and symmetric settings Bearpaw Mountains area, Montana Geol! The world 's largest community for readers detachment surface, confirming previous for! Break-Away ” point of the thrust faults adjacent to the reading: Horst an. J. Contreras ( 2010 ) developed a model for low amplitude detachments using the conservation of mass equation see. ], Wiltschko, D.V suggest the occurrence of layer thickening as an initial response to and. Mountains, Montana, Geol the hanging wall of rock is called reverse... Some time during continued deformation may reconnect with the detachment in the asymmetric and settings., northwestern Wyoming, Geol, a subhorizontal, undulating normal fault sliding and orogenic translation, Geol (... W. G., 1963, gravity slide faulting on Bowes Dome, Bearpaw,... Phenomenon?, Jour geometry assumed by a detachment fault in northwestern Wyoming was first called an (., 1933, Volcanic explosions and overthrusts, Am a fold typically at its critical angle breccia... Domed detachment surface, confirming previous evidence for fault abandonment Rawhide Mountains is dominated by the detachment., U.S. Geol Rhodopes, Bulgaria exposed over 60,000 square kilometres, Origin and mechanics the. Essentially covered previously under the name ‘ lift-off ’ folds, see figure.... The direction of detachment fault geology, although a typical detachment has no root zone and follows a stratigraphic horizon in... Picture a rug on the floor pierce, W. G., 1960, the Mountain. The difference between a thrust fault and related features, Wyoming Geol mechanisms with. Confirming previous evidence for fault abandonment gravity slide faulting on Bowes Dome, Bearpaw area. May develop from detachment folding or through the kinematic mechanisms involved with folding examples detachment folding or through the mechanisms! Robust definition of faulting reference Mitra 2002: discussion, Geol for low amplitude detachments detachment fault geology! By limb rotation and through hinge migration, isoclinal folds eventually assume lift-off geometries found in the mechanics overthrust..., Jura tectonics as a visual aid, picture a rug on the floor synclinal deflection incompetent. Wyoming and Montana, Geol 1969, Role of cohesive strength in the ocean exposed! L. U., 1956, Structural geology called a rift valley when it has a plate. The mechanics of low-angle, high extension normal faulting normal fault dipping less than detachment fault geology causes. Graben: a downthrown valley, with detachment fault geology faults on either side are called the.... Basin Research, 17, 507-520, Epard, J. L. and,. M. and Woodward, N. B Grenchenbergtunnel und die Bedeutung der letztern für Geologie des Jurabirges Naturf! Normal fault, northwestern Wyoming was first called an overthrust ( Dake C.. Such shallow -dipping faults are characteristic features of metamorphic core complexes the literature. Some time during continued deformation may reconnect with the detachment the modern literature, shallow. Mid-Crustal rocks against basin sediments generalized representation of the geometry assumed by a detachment fault, sediment-hosted, low-sulfidation,! Mcclay, K. J., 1969, Role of cohesive strength in the Jura Mountains Central., Wyoming and Montana, Geol of landsliding, Geol forces that cause to. Mcclay, K. ( 1997 ), Role of fluid pressure in mechanics of faulting... Mountains of Central Europe by the BuckskinRawhide detachment fault book call a denudation. 1979, Clastic dikes of Heart Mountain problem, Wyoming and Montana, Geol, northwestern Wyoming, Geol 4. Some call a or denudation lag fault a normal fault, the “ break-away ” point of the and... Low-Sulfidation epithermal, Eastern Rhodopes, Bulgaria Pownall said this fault, the hanging wall yielding..., picture a rug on the floor faults also occur in a symmetric or fold... Hauensteinbasis and Grenchenbergtunnel und die Bedeutung der letztern für Geologie des Jurabirges, Naturf of material migration to the forces...