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| ===Transpression and transtension=== | | ===Transpression and transtension=== |
− | Strain partitioning is common within [[transpression|transpressive]] and [[transtension|transtensive]] tectonic domains.<ref name=TyesTik /><ref name=FossenNorsk>Teyssier, Christian; Tikoff, Basil; Markley, Michelle (1995). "Oblique plate motion and continental tectonics". Geology 23 (5). doi:10.1130/0091-7613(1995)023<0447:OPMACT>2.3.CO;2.</ref> Both regimes involve a component of pure shear (transpression - compressive, transtension - extensive) and a component of simple shear.<ref name=Fossen /><ref name=TyesTik /><ref name=FossenNorsk /> Strain may be partitioned by the development of a [[strike slip fault]] or [[shear zone]] across the actively deforming region.<ref name=TyesTik /><ref name=FossenNorsk /> | + | Strain partitioning is common within [[transpression|transpressive]] and [[transtension|transtensive]] tectonic domains.<ref name=TyesTik />Teyssier, Christian; Tikoff, Basil; Markley, Michelle (1995). "Oblique plate motion and continental tectonics". Geology 23 (5). doi:10.1130/0091-7613(1995)023<0447:OPMACT>2.3.CO;2.<ref name=FossenNorsk></ref> Both regimes involve a component of pure shear (transpression - compressive, transtension - extensive) and a component of simple shear.<ref name=Fossen /><ref name=TyesTik /><ref name=FossenNorsk /> Strain may be partitioned by the development of a [[strike slip fault]] or [[shear zone]] across the actively deforming region.<ref name=TyesTik /><ref name=FossenNorsk /> |
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| ==== Example: Coast Mountains British Columbia ==== | | ==== Example: Coast Mountains British Columbia ==== |
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− | The [[Coast Mountains]] of British Columbia are interpreted as a transpressive orogen which formed during the [[Cretaceous]].<ref name=CPCTect>{{cite journal|last1=Chardon|first1=Dominique|last2=Andronicos|first2=Christopher|last3=Hollister|first3=Lincoln|title=Large-scale transpressive shear zone patterns and displacements within magmatic arcs: The Coast Plutonic Complex, British Columbia|journal=Tectonics|date=1999|volume=18|issue=2|pages=278–292}}</ref> Oblique subduction induced the development of several shear zones which strike parallel to the orogen.<ref name=CPCTect /> The presence of these shear zones suggest that strain is partitioned within the Coast Orogen which resulted in horizontal translation of terranes for several hundred kilometers parallel to the orogen.<ref name=CPCTect /> | + | The [[Coast Mountains]] of British Columbia are interpreted as a transpressive orogen which formed during the [[Cretaceous]].<ref name=CPCTect>Chardon, Dominique; Andronicos, Christopher; Hollister, Lincoln (1999). "Large-scale transpressive shear zone patterns and displacements within magmatic arcs: The Coast Plutonic Complex, British Columbia". Tectonics 18 (2): 278–292.</ref> Oblique subduction induced the development of several shear zones which strike parallel to the orogen.<ref name=CPCTect /> The presence of these shear zones suggest that strain is partitioned within the Coast Orogen which resulted in horizontal translation of terranes for several hundred kilometers parallel to the orogen.<ref name=CPCTect /> |
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| [[File:TranpTrans2.jpeg|600px|thumbnail|center|Block diagram illustrating the difference between homogeneous and partitioned strain within transpressive and transtensive tectonic regimes. The partitioning of strain occurs through the development of a strike slip or shear zone (shown with red arrows) across the actively deforming region (brown). Adaptation and modification from (Teyssier et al, 1995;<ref name=TyesTik>{{cite journal|last1=Teyssier|first1=Christian|last2=Tikoff|first2=Basil|last3=Markley|first3=Michelle|title=Oblique plate motion and continental tectonics|journal=Geology|date=1995|volume=23|issue=5|doi=10.1130/0091-7613(1995)023<0447:OPMACT>2.3.CO;2}}</ref> Fossen, 2012;<ref name=Fossen /> Jones and Tanner, 1995;<ref name=Jones&Tanner /> Sanderson and Marchini, 1984<ref name=Transpression />)]] | | [[File:TranpTrans2.jpeg|600px|thumbnail|center|Block diagram illustrating the difference between homogeneous and partitioned strain within transpressive and transtensive tectonic regimes. The partitioning of strain occurs through the development of a strike slip or shear zone (shown with red arrows) across the actively deforming region (brown). Adaptation and modification from (Teyssier et al, 1995;<ref name=TyesTik>{{cite journal|last1=Teyssier|first1=Christian|last2=Tikoff|first2=Basil|last3=Markley|first3=Michelle|title=Oblique plate motion and continental tectonics|journal=Geology|date=1995|volume=23|issue=5|doi=10.1130/0091-7613(1995)023<0447:OPMACT>2.3.CO;2}}</ref> Fossen, 2012;<ref name=Fossen /> Jones and Tanner, 1995;<ref name=Jones&Tanner /> Sanderson and Marchini, 1984<ref name=Transpression />)]] |
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| ===Strain factorization=== | | ===Strain factorization=== |
− | Strain factorization is a mathematical approach to quantify and characterize the variation of strain components in terms of the intensity and distribution that produces the finite strain throughout a deformed region.<ref name=Transpression>{{cite journal|last1=Sanderson|first1=David|last2=Marchini|first2=W.R.D.|title=Transpression|journal=Journal of Structural Geology|date=1984|volume=6|issue=5|pages=449–458}}</ref><ref name=RamsayHuber1 /><ref name=RamsayHuber2 /><ref name=Evans&Dunne>{{cite journal|last1=Evans|first1=Mark|last2=Dunne|first2=William|title=Strain factorization and partitioning in the North Mountain thrust sheet, central Appalachians, U.S.A.|journal=Journal of Structural Geology|date=1991|volume=13|issue=1|pages=21–35}}</ref> This effort is achieved through matrix multiplication.<ref name=RamsayHuber1>{{cite book|last1=Ramsay|first1=John|last2=Huber|first2=Martin|title=The Techniques of Modern Structural Geology Volume 1: Strain Analysis|date=1983|publisher=Academic Press|location=London|isbn=0-12-576901-6}}</ref><ref name=RamsayHuber2>{{cite book|last1=Ramsay|first1=John|last2=Huber|first2=Martin|title=The Techniques of Modern Structural Geology Volume 2: Folds and Fractures|date=1987|publisher=Academic Press|location=London|isbn=0-12-576902-4}}</ref> Refer to the figure below to conceptually visualize what is obtained through strain factorization. | + | Strain factorization is a mathematical approach to quantify and characterize the variation of strain components in terms of the intensity and distribution that produces the finite strain throughout a deformed region.<ref name=Transpression>Sanderson, David; Marchini, W.R.D. (1984). "Transpression". Journal of Structural Geology 6 (5): 449–458.</ref><ref name=RamsayHuber1 /><ref name=RamsayHuber2 /><ref name=Evans&Dunne>{{cite journal|last1=Evans|first1=Mark|last2=Dunne|first2=William|title=Strain factorization and partitioning in the North Mountain thrust sheet, central Appalachians, U.S.A.|journal=Journal of Structural Geology|date=1991|volume=13|issue=1|pages=21–35}}</ref> This effort is achieved through matrix multiplication.<ref name=RamsayHuber1>Ramsay, John; Huber, Martin (1983). The Techniques of Modern Structural Geology Volume 1: Strain Analysis. London: Academic Press. ISBN 0-12-576901-6.</ref><ref name=RamsayHuber2>{{cite book|last1=Ramsay|first1=John|last2=Huber|first2=Martin|title=The Techniques of Modern Structural Geology Volume 2: Folds and Fractures|date=1987|publisher=Academic Press|location=London|isbn=0-12-576902-4}}</ref> Refer to the figure below to conceptually visualize what is obtained through strain factorization. |
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| [[File:SpFactor3.jpeg|600px|thumbnail|center|Conceptual illustration of strain factorization. This highlights how the order of superposition of pure and simple shear components produce differing geometries, as matrix multiplication is non-communicative. Adaptation and modifications from Ramsay and Huber, 1983;<ref name=RamsayHuber1 /> Ramsay and Huber, 1987<ref name=RamsayHuber2 />]] | | [[File:SpFactor3.jpeg|600px|thumbnail|center|Conceptual illustration of strain factorization. This highlights how the order of superposition of pure and simple shear components produce differing geometries, as matrix multiplication is non-communicative. Adaptation and modifications from Ramsay and Huber, 1983;<ref name=RamsayHuber1 /> Ramsay and Huber, 1987<ref name=RamsayHuber2 />]] |