%0 Journal Article %1 Cook:2008 %A Cook, Kristen L. %A Royden, Leigh H. %D 2008 %I AGU %J J. Geophys. Res. %K 0545 8110 8159 9320 Asia; Computational Continental Geographic Geophysics: Location: Modeling Rheology: Tectonophysics: Tibet; and crust crustal flow; general; lithosphere; tectonics: %N B8 %T The role of crustal strength variations in shaping orogenic plateaus, with application to Tibet %U http://dx.doi.org/10.1029/2007JB005457 %V 113 %X The Tibetan Plateau is the type example of a large orogenic plateau formed as a result of continent-continent collision. The morphology of the plateau and its margins suggests that preexisting variations in crustal strength have influenced the growth of the plateau. We have developed a three-dimensional numerical model of deformation in a viscous crust in order to investigate the effects of lateral heterogeneities on plateau growth. The model includes a two layer crust and allows for lateral variation of viscosity in both the upper and lower layers. Model results indicate that crustal strength variations have a dramatic effect on the morphology and dynamics of a developing plateau. A region of strong crust is characterized by a very steep plateau margin that propagates extremely slowly, does not accommodate significant shortening strain, and is subparallel to local upper and lower crustal velocities. A weak crustal region develops a gently sloping margin; uplift propagates rapidly across the weak zone, and crustal material within the plateau is diverted toward the low-strength region. With a relatively simple distribution of strength variations, corresponding to strong Tarim and Sichuan Basin crust and a weak southeastern corner, our model produces a plateau with many similarities to the Tibetan Plateau, including the overall morphology, rotation around the eastern syntaxis, and E&\#8211;W extension. Analysis of model results suggests that E&\#8211;W extension of the central plateau may be related to the rapid eastward flow of crustal material into a weak zone in the SE corner without significant change in plateau elevation. %@ 0148-0227

@article{Cook:2008, abstract = {The Tibetan Plateau is the type example of a large orogenic plateau formed as a result of continent-continent collision. The morphology of the plateau and its margins suggests that preexisting variations in crustal strength have influenced the growth of the plateau. We have developed a three-dimensional numerical model of deformation in a viscous crust in order to investigate the effects of lateral heterogeneities on plateau growth. The model includes a two layer crust and allows for lateral variation of viscosity in both the upper and lower layers. Model results indicate that crustal strength variations have a dramatic effect on the morphology and dynamics of a developing plateau. A region of strong crust is characterized by a very steep plateau margin that propagates extremely slowly, does not accommodate significant shortening strain, and is subparallel to local upper and lower crustal velocities. A weak crustal region develops a gently sloping margin; uplift propagates rapidly across the weak zone, and crustal material within the plateau is diverted toward the low-strength region. With a relatively simple distribution of strength variations, corresponding to strong Tarim and Sichuan Basin crust and a weak southeastern corner, our model produces a plateau with many similarities to the Tibetan Plateau, including the overall morphology, rotation around the eastern syntaxis, and E\&{\#}8211;W extension. Analysis of model results suggests that E\&{\#}8211;W extension of the central plateau may be related to the rapid eastward flow of crustal material into a weak zone in the SE corner without significant change in plateau elevation.}, added-at = {2010-08-12T23:06:12.000+0200}, author = {Cook, Kristen L. and Royden, Leigh H.}, bdsk-url-1 = {http://dx.doi.org/10.1029/2007JB005457}, biburl = {https://www.bibsonomy.org/bibtex/26998c6b8b70ceb060944803af9a29e2d/jkmacc}, date-added = {2010-04-03 11:57:04 -0600}, date-modified = {2010-04-03 11:57:04 -0600}, do = {10.1029/2007JB005457}, interhash = {90e524b5196f28b8dedbf012ad12e3bd}, intrahash = {6998c6b8b70ceb060944803af9a29e2d}, isbn = {0148-0227}, journal = {J. Geophys. Res.}, keywords = {0545 8110 8159 9320 Asia; Computational Continental Geographic Geophysics: Location: Modeling Rheology: Tectonophysics: Tibet; and crust crustal flow; general; lithosphere; tectonics:}, month = {08}, number = {B8}, publisher = {AGU}, sp = {B08407}, timestamp = {2010-08-12T23:06:15.000+0200}, title = {The role of crustal strength variations in shaping orogenic plateaus, with application to Tibet}, ty = {JOUR}, url = {http://dx.doi.org/10.1029/2007JB005457}, volume = 113, year = 2008 }