@article{SocquetValdesJaraetal.2017, author = {Socquet, Anne and Valdes, Jesus Pina and Jara, Jorge and Cotton, Fabrice Pierre and Walpersdorf, Andrea and Cotte, Nathalie and von Specht, Sebastian and Ortega-Culaciati, Francisco and Carrizo, Daniel and Norabuena, Edmundo}, title = {An 8month slow slip event triggers progressive nucleation of the 2014 Chile megathrust}, series = {Geophysical research letters}, volume = {44}, journal = {Geophysical research letters}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0094-8276}, doi = {10.1002/2017GL073023}, pages = {4046 -- 4053}, year = {2017}, abstract = {The mechanisms leading to large earthquakes are poorly understood and documented. Here we characterize the long-term precursory phase of the 1 April 2014 M(w)8.1 North Chile megathrust. We show that a group of coastal GPS stations accelerated westward 8months before the main shock, corresponding to a M(w)6.5 slow slip event on the subduction interface, 80\% of which was aseismic. Concurrent interface foreshocks underwent a diminution of their radiation at high frequency, as shown by the temporal evolution of Fourier spectra and residuals with respect to ground motions predicted by recent subduction models. Such ground motions change suggests that in response to the slow sliding of the subduction interface, seismic ruptures are progressively becoming smoother and/or slower. The gradual propagation of seismic ruptures beyond seismic asperities into surrounding metastable areas could explain these observations and might be the precursory mechanism eventually leading to the main shock.}, language = {en} } @article{JoziNajafabadiHaberlandLeBretonetal.2022, author = {Jozi Najafabadi, Azam and Haberland, Christian and Le Breton, Eline and Handy, Mark R. and Verwater, Vincent F. and Heit, Benjamin and Weber, Michael}, title = {Constraints on crustal structure in the vicinity of the adriatic indenter (European Alps) from Vp and Vp/Vs local earthquake tomography}, series = {Journal of geophysical research : Solid earth}, volume = {127}, journal = {Journal of geophysical research : Solid earth}, number = {2}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9313}, doi = {10.1029/2021JB023160}, pages = {22}, year = {2022}, abstract = {In this study, 3-D models of P-wave velocity (Vp) and P-wave and S-wave ratio (Vp/Vs) of the crust and upper mantle in the Eastern and eastern Southern Alps (northern Italy and southern Austria) were calculated using local earthquake tomography (LET). The data set includes high-quality arrival times from well-constrained hypocenters observed by the dense, temporary seismic networks of the AlpArray AASN and SWATH-D. The resolution of the LET was checked by synthetic tests and analysis of the model resolution matrix. The small inter-station spacing (average of similar to 15 km within the SWATH-D network) allowed us to image crustal structure at unprecedented resolution across a key part of the Alps. The derived P velocity model revealed a highly heterogeneous crustal structure in the target area. One of the main findings is that the lower crust is thickened, forming a bulge at 30-50 km depth just south of and beneath the Periadriatic Fault and the Tauern Window. This indicates that the lower crust decoupled both from its mantle substratum as well as from its upper crust. The Moho, taken to be the iso-velocity contour of Vp = 7.25 km/s, agrees with the Moho depth from previous studies in the European and Adriatic forelands. It is shallower on the Adriatic side than on the European side. This is interpreted to indicate that the European Plate is subducted beneath the Adriatic Plate in the Eastern and eastern Southern Alps.}, language = {en} } @phdthesis{Freisleben2023, author = {Freisleben, Roland}, title = {Deciphering the mechanisms of permanent forearc deformation based on marine terraces}, doi = {10.25932/publishup-61035}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-610359}, school = {Universit{\"a}t Potsdam}, pages = {xiv, 153}, year = {2023}, abstract = {The Andes reflect Cenozoic deformation and uplift along the South American margin in the context of regional shortening associated with the interaction between the subducting Nazca plate and the overriding continental South American plate. Simultaneously, multiple levels of uplifted marine terraces constitute laterally continuous geomorphic features related to the accumulation of permanent forearc deformation in the coastal realm. However, the mechanisms responsible for permanent coastal uplift and the persistency of current/decadal deformation patterns over millennial timescales are still not fully understood. This dissertation presents a continental-scale database of last interglacial terrace elevations and uplift rates along the South American coast that provides the basis for an analysis of a variety of mechanisms that are possibly responsible for the accumulation of permanent coastal uplift. Regional-scale mapping and analysis of multiple, late Pleistocene terrace levels in central Chile furthermore provide valuable insights regarding the persistency of current seismic asperities, the role of upper-plate faulting, and the impact of bathymetric ridges on permanent forearc deformation. The database of last interglacial terrace elevations reveals an almost continuous signal of background-uplift rates along the South American coast at ~0.22 mm/yr that is modified by various short- to long-wavelength changes. Spatial correlations with crustal faults and subducted bathymetric ridges suggest long-term deformation to be affected by these features, while the latitudinal variability of climate forcing factors has a profound impact on the generation and preservation of marine terraces. Systematic wavelength analyses and comparisons of the terrace-uplift rate signal with different tectonic parameters reveal short-wavelength deformation to result from crustal faulting, while intermediate- to long-wavelength deformation might indicate various extents of long-term seismotectonic segments on the megathrust, which are at least partially controlled by the subduction of bathymetric anomalies. The observed signal of background-uplift rate is likely accumulated by moderate earthquakes near the Moho, suggesting multiple, spatiotemporally distinct phases of uplift that manifest as a continuous uplift signal over millennial timescales. Various levels of late Pleistocene marine terraces in the 2015 M8.3 Illapel-earthquake area reveal a range of uplift rates between 0.1 and 0.6 mm/yr and indicate decreasing uplift rates since ~400 ka. These glacial-cycle uplift rates do not correlate with current or decadal estimates of coastal deformation suggesting seismic asperities not to be persistent features on the megathrust that control the accumulation of permanent forearc deformation over long timescales of 105 years. Trench-parallel, crustal normal faults modulate the characteristics of permanent forearc-deformation; upper-plate extension likely represents a second-order phenomenon resulting from subduction erosion and subsequent underplating that lead to regional tectonic uplift and local gravitational collapse of the forearc. In addition, variable activity with respect to the subduction of the Juan Fern{\´a}ndez Ridge can be detected in the upper plate over the course of multiple interglacial periods, emphasizing the role of bathymetric anomalies in causing local increases in terrace-uplift rate. This thesis therefore provides new insights into the current understanding of subduction-zone processes and the dynamics of coastal forearc deformation, whose different interacting forcing factors impact the topographic and geomorphic evolution of the western South American coast.}, language = {en} } @article{KonradSchmolkeO'BrienZack2011, author = {Konrad-Schmolke, Matthias and O'Brien, Patrick J. and Zack, Thomas}, title = {Fluid Migration above a Subducted Slab-Constraints on Amount, Pathways and Major Element Mobility from Partially Overprinted Eclogite-facies Rocks (Sesia Zone, Western Alps)}, series = {Journal of petrology}, volume = {52}, journal = {Journal of petrology}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-3530}, doi = {10.1093/petrology/egq087}, pages = {457 -- 486}, year = {2011}, abstract = {The Western Alpine Sesia-Lanzo Zone (SLZ) is a sliver of eclogite-facies continental crust exhumed from mantle depths in the hanging wall of a subducted oceanic slab. Eclogite-facies felsic and basic rocks sampled across the internal SLZ show different degrees of retrograde metamorphic overprint associated with fluid influx. The weakly deformed samples preserve relict eclogite-facies mineral assemblages that show partial fluid-induced compositional re-equilibration along grain boundaries, brittle fractures and other fluid pathways. Multiple fluid influx stages are indicated by replacement of primary omphacite by phengite, albitic plagioclase and epidote as well as partial re-equilibration and/or overgrowths in phengite and sodic amphibole, producing characteristic step-like compositional zoning patterns. The observed textures, together with the map-scale distribution of the samples, suggest open-system, pervasive and reactive fluid flux across large rock volumes above the subducted slab. Thermodynamic modelling indicates a minimum amount of fluid of 0 center dot 1-0 center dot 5 wt \% interacting with the wall-rocks. Phase relations and reaction textures indicate mobility of K, Ca, Fe and Mg, whereas Al is relatively immobile in these medium-temperature-high-pressure fluids. Furthermore, the thermodynamic models show that recycling of previously fractionated material, such as in the cores of garnet porphyroblasts, largely controls the compositional re-equilibration of the exhumed rock body.}, language = {en} } @article{SakiMiriOberhaensli2020, author = {Saki, Adel and Miri, Mirmohammad and Oberh{\"a}nsli, Roland}, title = {High temperature - low pressure metamorphism during subduction of Neo-Tethys beneath the Iranian plate}, series = {Mineralogy and petrology}, volume = {114}, journal = {Mineralogy and petrology}, number = {6}, publisher = {Springer}, address = {Wien [u.a.]}, issn = {0930-0708}, doi = {10.1007/s00710-020-00721-z}, pages = {539 -- 557}, year = {2020}, abstract = {Subduction of Neo-Tethys oceanic lithosphere beneath the Iranian plate during the Mesozoic formed several igneous bodies of ultramafic to intermediate and felsic composition. Intrusion of these magmas into a regional metamorphic sequence (the Sanandaj-Sirjan Zone) caused partial melting and formation of migmatites with meta-pelitic protoliths. The Alvand complex (west Iran) is a unique area comprising migmatites of both mafic and pelitic protoliths. In this area, the gabbroic rocks contain veins of leucosome at their contact with pyroxenite and olivine gabbro. These leucosomes are geochemically and mineralogically different from leucosomes of the meta-pelitic migmatites and clearly show properties of I-type granites. Microscopic observations and whole rock compositions of the mafic migmatite leucosomes show that migmatization occurred through partial melting of biotite, hornblende and plagioclase. Thermobarometric calculations indicate 800 degrees C and 3.7 kbar for partial melting, although phase diagram modeling demonstrates that the presence of water could decrease the solidus temperature by about 40 degrees C. Our results suggest an asthenospheric magma upwelling as the source of heat for partial melting of the gabbroic rock during subduction of Neo-Tethys oceanic crust under the western edge of the Iranian plate. The present study also reveals relationships between migmatization and formation of S- and I -type granites in the area.}, language = {en} } @phdthesis{Muldashev2017, author = {Muldashev, Iskander}, title = {Modeling of the great earthquake seismic cycles}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-398926}, school = {Universit{\"a}t Potsdam}, pages = {xii, 117}, year = {2017}, abstract = {The timing and location of the two largest earthquakes of the 21st century (Sumatra, 2004 and Tohoku 2011, events) greatly surprised the scientific community, indicating that the deformation processes that precede and follow great megathrust earthquakes remain enigmatic. During these phases before and after the earthquake a combination of multi-scale complex processes are acting simultaneously: Stresses built up by long-term tectonic motions are modified by sudden jerky deformations during earthquakes, before being restored by multiple ensuing relaxation processes. This thesis details a cross-scale thermomechanical model developed with the aim of simulating the entire subduction process from earthquake (1 minute) to million years' time scale, excluding only rupture propagation. The model employs elasticity, non-linear transient viscous rheology, and rate-and-state friction. It generates spontaneous earthquake sequences, and, by using an adaptive time-step algorithm, recreates the deformation process as observed naturally over single and multiple seismic cycles. The model is thoroughly tested by comparing results to those from known high- resolution solutions of generic modeling setups widely used in modeling of rupture propagation. It is demonstrated, that while not modeling rupture propagation explicitly, the modeling procedure correctly recognizes the appearance of instability (earthquake) and correctly simulates the cumulative slip at a fault during great earthquake by means of a quasi-dynamic approximation. A set of 2D models is used to study the effects of non-linear transient rheology on the postseismic processes following great earthquakes. Our models predict that the viscosity in the mantle wedge drops by 3 to 4 orders of magnitude during a great earthquake with magnitude above 9. This drop in viscosity results in spatial scales and timings of the relaxation processes following the earthquakes that are significantly different to previous estimates. These models replicate centuries long seismic cycles exhibited by the greatest earthquakes (like the Great Chile 1960 Earthquake) and are consistent with the major features of postseismic surface displacements recorded after the Great Tohoku Earthquake. The 2D models are also applied to study key factors controlling maximum magnitudes of earthquakes in subduction zones. Even though methods of instrumentally observing earthquakes at subduction zones have rapidly improved in recent decades, the characteristic recurrence interval of giant earthquakes (Mw>8.5) is much larger than the currently available observational record and therefore the necessary conditions for giant earthquakes are not clear. Statistical studies have recognized the importance of the slab shape and its surface roughness, state of the strain of the upper plate and thickness of sediments filling the trenches. In this thesis we attempt to explain these observations and to identify key controlling parameters. We test a set of 2D models representing great earthquake seismic cycles at known subduction zones with various known geometries, megathrust friction coefficients, and convergence rates implemented. We found that low-angle subduction (large effect) and thick sediments in the subduction channel (smaller effect) are the fundamental necessary conditions for generating giant earthquakes, while the change of subduction velocity from 10 to 3.5 cm/yr has a lower effect. Modeling results also suggest that having thick sediments in the subduction channel causes low static friction, resulting in neutral or slightly compressive deformation in the overriding plate for low-angle subduction zones. These modeling results agree well with observations for the largest earthquakes. The model predicts the largest possible earthquakes for subduction zones of given dipping angles. The predicted maximum magnitudes exactly threshold magnitudes of all known giant earthquakes of 20th and 21st centuries. The clear limitation of most of the models developed in the thesis is their 2D nature. Development of 3D models with comparable resolution and complexity will require significant advances in numerical techniques. Nevertheless, we conducted a series of low-resolution 3D models to study the interaction between two large asperities at a subduction interface separated by an aseismic gap of varying width. The novelty of the model is that it considers behavior of the asperities during multiple seismic cycles. As expected, models show that an aseismic gap with a narrow width could not prevent rupture propagation from one asperity to another, and that rupture always crosses the entire model. When the gap becomes too wide, asperities do not interact anymore and rupture independently. However, an interesting mode of interaction was observed in the model with an intermediate width of the aseismic gap: In this model the asperities began to stably rupture in anti-phase following multiple seismic cycles. These 3D modeling results, while insightful, must be considered preliminary because of the limitations in resolution. The technique developed in this thesis for cross-scale modeling of seismic cycles can be used to study the effects of multiple seismic cycles on the long-term deformation of the upper plate. The technique can be also extended to the case of continental transform faults and for the advanced 3D modeling of specific subduction zones. This will require further development of numerical techniques and adaptation of the existing advanced highly scalable parallel codes like LAMEM and ASPECT.}, language = {en} } @phdthesis{Martin2005, author = {Martin, Sebastian}, title = {Subduction zone wave guides : deciphering slab structure using intraslab seismicity at the Chile-Peru subduction zone}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-5820}, school = {Universit{\"a}t Potsdam}, year = {2005}, abstract = {Subduction zones are regions of intense earthquake activity up to great depth. Sources are located inside the subducting lithosphere and, as a consequence, seismic radiation from subduction zone earthquakes is strongly affected by the interior slab structure. The wave field of these intraslab events observed in the forearc region is profoundly influenced by a seismically slow layer atop the slab surface. This several kilometer thick low-velocity channel (wave guide) causes the entrapment of seismic energy producing strong guided wave phases that appear in P onsets in certain regions of the forearc. Observations at the Chile-Peru subduction zone presented here, as well as observations at several other circum-pacific subduction zones show such signals. Guided wave analysis contributes details of immense value regarding the processes near the slab surface, such as layering of subducted lithosphere, source locations of intraslab seismicity and most of all, range and manner of mineralogical phase transitions. Seismological data stem from intermediate depth events (depth range 70 km - 300 km) recorded in northern Chile near 21 Grad S during the collaborative research initiative " Deformation Processes in the Andes" (SFB 267). A subset of stations - all located within a slab-parallel transect close to 69 Grad W - show low-frequency first arrivals (2 Hz), sometimes followed by a second high-frequency phase. We employ 2-dimensional finite-difference simulations of complete P-SV wave propagation to explore the parameter space of subduction zone wave guides and explain the observations. Key processes underlying the guided wave propagation are studied: Two distinct mechanisms of decoupling of trapped energy from the wave guide are analyzed - a prerequisite to observe the phases at stations located at large distances from the wave guide (up to 100 km). Variations of guided wave effects perpendicular to the strike of the subduction zone are investigated, such as the influence of phases traveling in the fast slab. Further, the merits and limits of guided wave analysis are assessed. Frequency spectra of the guided wave onsets prove to be a robust quantity that captures guided wave characteristics at subduction zones including higher mode excitation. They facilitate the inference of wave guide structure and source positioning: The peak frequency of the guided wave fundamental mode is associated with a certain combination of layer width and velocity contrast. The excitation strength of the guided wave fundamental mode and higher modes is associated with source position and orientation relative to the low-velocity layer. The guided wave signals at the Chile-Peru subduction zone are caused by energy that leaks from the subduction zone wave guide. On the one hand, the bend shape of the slab allows for leakage at a depth of 100 km. On the other, equalization of velocities between the wave guide and the host rocks causes further energy leakage at the contact zone between continental and oceanic crust (70 km depth). Guided waves bearing information on deep slab structure can therefore be recorded at specific regions in the forearc. These regions are determined based on slab geometry, and their locations coincide with the observations. A number of strong constraints on the structure of the Chile-Peru slab are inferred: The deep wave guide for intraslab events is formed by a layer of 2 km average width that remains seismically slow (7 percent velocity reduction compared to surrounding mantle). This low-velocity layer at the top of the Chile-Peru slab is imaged from a depth of 100 km down to at least 160 km. Intermediate depth events causing the observed phases are located inside the layer or directly beneath it in the slab mantle. The layer is interpreted as partially eclogized lower oceanic crust persisting to depth beyond the volcanic arc.}, subject = {Anden}, language = {en} } @article{OhuchiNishiharaKawazoeetal.2012, author = {Ohuchi, Tomohiro and Nishihara, Yu and Kawazoe, Takaaki and Spengler, Dirk and Shiraishi, Rei and Suzuki, Akio and Kikegawa, Takumi and Ohtani, Eiji}, title = {Superplasticity in hydrous melt-bearing dunite Implications for shear localization in Earth's upper mantle}, series = {Earth \& planetary science letters}, volume = {335}, journal = {Earth \& planetary science letters}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2012.04.032}, pages = {59 -- 71}, year = {2012}, abstract = {Deformation experiments on hydrous melt-bearing dunite (olivine+4 vol\% orthopyroxene+4 vol\% clinopyroxene with less than 2.5 vol\% of the melt phase) were conducted at pressures of 1.3-5.7 GPa and temperatures of 1270-1490 K in order to explore the effect of intergranular fluids on the plastic flow of olivine in Earth's upper mantle. The strain rate was proportional to steady-state creep strength to the 2.1 power, and the creep strength markedly increased with increase in grain size. Developments of the crystallographic preferred orientation of olivine and flattening of olivine grains were hardly observed even after 33-55\% shortening of the samples. These observations show that grain boundary sliding (GBS) dominated the deformation of olivine (i.e., superplasticity). The creep strength of hydrous melt-bearing dunite was 2-5 times lower than that of melt-free dunite. The dependence of creep rate on melt fraction is known to be expressed empirically as (epsilon) over dot(phi) = (epsilon) over dot(0) exp(alpha phi), where alpha is a constant and phi is the melt fraction. The experimentally obtained value of alpha was in the range of 150-230, corresponding to 5-7 times the reported values for the olivine-basalt system at 0.3 GPa (i.e., creep strength of dunite was efficiently reduced by the hydrous melt). Superplasticity is the dominant creep mechanism of olivine in fluid-bearing fine-grained peridotites under low-temperature and high-stress conditions (i.e., peridotite shear zones in the upper mantle). Superplasticity induced by geological fluids would play an important role in the shear localization (and thus initiation of subduction) in the upper mantle.}, language = {en} } @article{KonradSchmolkeBabistHandyetal.2006, author = {Konrad-Schmolke, Matthias and Babist, Jochen and Handy, Mark R. and O'brien, Patrick J.}, title = {The physico-chemical properties of a subducted slab from garnet zonation patterns (Sesia Zone, Western Alps)}, series = {Journal of petrology}, volume = {47}, journal = {Journal of petrology}, number = {11}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0022-3530}, doi = {10.1093/petrology/egl039}, pages = {2123 -- 2148}, year = {2006}, abstract = {Garnets in continentally derived high-pressure (HP) rocks of the Sesia Zone (Western Alps) exhibit three different chemical zonation patterns, depending on sample locality. Comparison of observed garnet zonation patterns with thermodynamically modelled patterns shows that the different patterns are caused by differences in the water content of the subducted protoliths during prograde metamorphism. Zonation patterns of garnets in water-saturated host rocks show typical prograde chemical zonations with steadily increasing pyrope content and increasing XMg, together with bell-shaped spessartine patterns. In contrast, garnets in water-undersaturated rocks have more complex zonation patterns with a characteristic decrease in pyrope and XMg between core and inner rim. In some cases, garnets show an abrupt compositional change in core-to-rim profiles, possibly due to water-undersaturation prior to HP metamorphism. Garnets from both water-saturated and water-undersaturated rocks show signs of intervening growth interruptions and core resorption. This growth interruption results from bulk-rock depletion caused by fractional garnet crystallization. The water content during burial influences significantly the physical properties of the subducted rocks. Due to enhanced garnet crystallization, water-undersaturated rocks, i.e. those lacking a free fluid phase, become denser than their water-saturated equivalents, facilitating the subduction of continental material. Although water-bearing phases such as phengite and epidote are stable up to eclogite-facies conditions in these rocks, dehydration reactions during subduction are lacking in water-undersaturated rocks up to the transition to the eclogite facies, due to the thermodynamic stability of such hydrous phases at high P-T conditions. Our calculations show that garnet zonation patterns strongly depend on the mineral parageneses stable during garnet growth and that certain co-genetic mineral assemblages cause distinct garnet zonation patterns. This observation enables interpretation of complex garnet growth zonation patterns in terms of garnet-forming reactions and water content during HP metamorphism, as well determination of detailed P-T paths.}, language = {en} } @phdthesis{Barrionuevo2020, author = {Barrionuevo, Mat{\´i}as}, title = {The role of the upper plate in the Andean tectonic evolution (33-36°S): insights from structural geology and numerical modeling}, doi = {10.25932/publishup-51590}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515909}, school = {Universit{\"a}t Potsdam}, pages = {148, S2}, year = {2020}, abstract = {Los Andes Centrales del Sur (33-36°S) son un gran laboratorio para el estudio de los procesos de deformaci{\´o}n orog{\´e}nica, donde las condiciones de borde, como la geometr{\´i}a de la placa subductada, imponen un importante control sobre la deformaci{\´o}n andina. Por otro lado, la Placa Sudamericana presenta una serie de heterogeneidades que tambi{\´e}n imparten un control sobre el modo de deformaci{\´o}n. El objetivo de esta tesis es probar el control de este {\´u}ltimo factor sobre la construcci{\´o}n del sistema orog{\´e}nico andino. A partir de la integraci{\´o}n de la informaci{\´o}n superficial y de subsuelo en el {\´a}rea sur (34°-36°S), se estudi{\´o} la evoluci{\´o}n de la deformaci{\´o}n andina sobre el segmento de subducci{\´o}n normal. Se desarroll{\´o} un modelo estructural que eval{\´u}a el estado de esfuerzos desde el Mioceno hasta la actualidad, el rol de estructuras previas y su influencia en la migraci{\´o}n de fluidos. Con estos datos y publicaciones previas de la zona norte del {\´a}rea de estudio (33°-34ºS), se realiz{\´o} un modelado num{\´e}rico geodin{\´a}mico para probar la hip{\´o}tesis del papel de las heterogeneidades de la placa superior en la evoluci{\´o}n andina. Se utilizaron dos c{\´o}digos (LAPEX-2D y ASPECT) basados en elementos finitos/diferencias finitas, que simulan el comportamiento de materiales con reolog{\´i}as elastoviscopl{\´a}sticas bajo deformaci{\´o}n. Los resultados del modelado sugieren que la deformaci{\´o}n contraccional de la placa superior est{\´a} significativamente controlada por la resistencia de la lit{\´o}sfera, que est{\´a} definida por la composici{\´o}n de la corteza superior e inferior y por la proporci{\´o}n del manto litosf{\´e}rico, que a su vez est{\´a} definida por eventos tect{\´o}nicos previos. Estos eventos previos tambi{\´e}n definieron la composici{\´o}n de la corteza y su geometr{\´i}a, que es otro factor que controla la localizaci{\´o}n de la deformaci{\´o}n. Con una composici{\´o}n de corteza inferior m{\´a}s f{\´e}lsica, la deformaci{\´o}n sigue un modo de cizalla pura mientras que las composiciones m{\´a}s m{\´a}ficas provocan un modo de deformaci{\´o}n tipo cizalla simple. Por otro lado, observamos que el espesor inicial de la lit{\´o}sfera controla la localizaci{\´o}n de la deformaci{\´o}n, donde zonas con lit{\´o}sfera m{\´a}s fina es propensa a concentrar la deformaci{\´o}n. Un l{\´i}mite lit{\´o}sfera-asten{\´o}sfera asim{\´e}trico, como resultado del flujo de la cu{\~n}a mant{\´e}lica tiende a generar despegues vergentes al E.}, language = {en} }