Crustal Buckling Research Articles

Large-scale topography of the north Tibetan ranges as a proxy for contrasted crustal-scale deformation modes

Forming the northern margin of the Cenozoic Himalayan–Tibetan orogen, the area surrounding the Qaidam Basin is a key region to study the mechanisms that govern the long-term evolution of intracontinental orogenic processes. Indeed, tectonic deformation in this region involves newly formed and inherited crustal and lithospheric structures, partition between horizontal and vertical movements, and a strong influence from external factors such as climate and erosion. This study proposes a description of the topography and crustal structure of the north Tibet ranges as an insight into their tectonic deformation characteristics. The topographic study includes the integrated analysis of regional topographic profiles, river profiles, slope maps and thermochronology data. The available geophysical, geological and structural data are used to draw regional, crustal-scale geological sections across northern Tibet to describe the regional crustal structure. We show that three deformation modes are expressed (block uplift, distributed shortening and crustal buckling) in structural compartments that involve either complete mountain ranges or some specific regions inside those ranges. We propose that a new crustal structure may develop parallel to the Altyn Tagh fault, connecting the eastern tip of the Qimen Tagh with the Haiyuan fault, across the Qaidam Basin. Supplementary material : Supplementary figures are available at https://doi.org/10.6084/m9.figshare.c.5841461 Thematic collection: This article is part of the Fold-and-thrust belts collection available at: https://www.lyellcollection.org/cc/fold-and-thrust-belts

Multiple-generation folding and non-coaxial strain of lava crusts

Viscoelastic strain in lava flows is commonly expressed as gravity-driven buckling of the lava crust. This surface folding process creates the well-known ropy pāhoehoe texture of basaltic lavas and the ogives and surface ridges of more compositionally evolved lava flows. Previous work has shown that surface fold wavelengths are proportional to the viscosity contrast between the lava crust and core, and to the thickness of the crust. Thus, fold analysis can be an important tool for understanding lava flow rheology. We analyze fold wavelength patterns of solidified natural lava flows from the Myvatn lava fields (Iceland), Piton de La Fournaise (La Reunion), and experimental lava flows from the Syracuse University Lava Project. In each case, lava flows exhibited two dominant wavelengths, consistent with multiple generations of coaxial folding. The ratio of the two dominant wavelengths for basalt (Iceland, La Reunion) is ~ 5:1 whereas the wavelength ratio for basaltic andesite (Syracuse) is ~ 3:1, suggesting a compositional control on deformation, as proposed by previous studies. Video analysis of incrementally folded Syracuse lava crusts reveals significant non-coaxial strain, which violates the assumptions of plane strain used in crustal buckling models. These results show that interpreting lava rheology from finite strain requires careful consideration of complex three-dimensional strain fields. Despite these complexities, the correlation between fold wavelength ratios and lava flow composition persists and may provide important insight into flow characterization.

Anomalous Streamflow and Groundwater-Level Changes Before the 1999 M7.6 Chi–Chi Earthquake in Taiwan: Possible Mechanisms

Streamflow recorded by a stream gauge located 4 km from the epicenter of the 1999 M7.6 Chi–Chi earthquake in central Taiwan showed a large and rapid anomalous increase of 124 m3/s starting 4 days before the earthquake. This increase was followed by a comparable co-seismic drop to below the background level for 8 months. In addition, groundwater-levels recorded at a well 1.5 km east of the seismogenic fault showed an anomalous rise 2 days before the earthquake, and then a unique 4-cm drop beginning 3 h before the earthquake. The anomalous streamflow increase is attributed to gravity-driven groundwater discharge into the creek through the openings of existing fractures in the steep creek banks crossed by the upstream Shueilikun fault zone, as a result of pre-earthquake crustal buckling. The continued tectonic movement and buckling, together with the downward flow of water in the crust, may have triggered the occurrence of some shallow slow-slip events in the Shueilikun and other nearby fault zones. When these events propagate down-dip to decollement, where the faults merges with the seismogenic Chelungpu fault, they may have triggered other slow-slip events propagating toward the asperity at the hypocenter and the Chelungpu fault. These events may then have caused the observed groundwater-level anomaly and helped to trigger the earthquake.

The role of lateral lithospheric strength heterogeneities in orogenic plateau growth: Insights from 3‐D thermo‐mechanical modeling

AbstractPreexisting lateral variations in crustal thickness and lithospheric thermal state are documented for the formation of some orogenic plateaux. Here we use high‐resolution 3‐D thermo‐mechanical simulations to investigate the influence of preexisting lateral lithospheric strength heterogeneity on the growth of orogenic plateau. The modeling results illustrate an episodic scenario for plateau growth: (1) an early rapid growth stage, characterized by rapid surface uplift and intensive crustal buckling and thickening; (2) an outward spreading stage, characterized by significant lateral expansion of the plateau edges; and (3) a mature stage, characterized by the development of the intracrustal partial melting and subduction of the surrounding lithosphere under the plateau. Sensitivity analyses indicate that lateral variation in crustal thickness favors outward spreading of orogenic plateau, while lateral variation in geothermal gradient favors crustal buckling. The model in absence of lateral strength heterogeneity leads to progressive migration of orogenic belt. Our models show that the plateau's lower crust is largely coupled with underlying lithospheric mantle and does not flow into the surrounding lithospheres, casting doubt on the lower crust flow model. We suggest that the Himalayan‐Tibetan orogenic system can be best understood within the framework that the proto‐southern Asian margin was fairly weak prior to the India‐Asia collision to steer the formation of a large hot orogenic plateau there.

Self-affinities of landforms and folds in the Northeast Honshu Arc, Japan

A method to analyze self-affinities is introduced and applied to the large scale fold geometries of Quaternary and Tertiary sediments or geographical topographies in the inner belt of the Northeast Honshu Arc, Japan. Based on this analysis, their geometries are self-affine and can be differently scaled in different directions. We recognize a crossover from local to global altitude (vertical) variation of the geometries of folds and topographies. The characteristic length for the crossover of topographies (landforms) is about 25 km and is related to the half wavelength of the crustal buckling folds or possible maximum magnitude of inland earthquakes in the Northeast Honshu Arc. Moreover, self-affinity of the folds and topographies can be connected with the b-value in Gutenberg-Richter℉s law. We obtain two average Hurst exponents obtained from the self-affinities of folds in the Northeast Honshu Arc. This indicates that there are two possible seismic modes for the smaller and larger ranges in the focal regions in the Northeast Honshu Arc.

Lithospheric-scale structures from the perspective of analogue continental collision

Analogue models were employed to investigate continental collision addressing the roles of (1) a suture zone separating different crustal blocks, (2) mid-crustal weak layers and (3) mantle strengths. These models confirmed that low-amplitude lithospheric and crustal buckling is the primary response to shortening with a wavelength mainly controlled by the strong upper crust and/or lithospheric mantle. With increasing shortening, bivergent thrusts formed across the brittle layers (equivalent to upper crust) at inflection points of the buckles while ductile layers (lower crust and mantle) continued being folded. The resulting geometries displayed pop-ups and pop-downs above the boundaries (sutures) between blocks. Further shortening led to wider, thrust-bounded deformation zones (Σ-belts) in front of the stronger blocks identified as “effective indenters”. During shortening upward extrusion into Σ-belts allowed exhumation of deep material. Weak layers enhanced strain localisation. These modelling results have similarity in large-scale structures of modern orogens and are relevant to the understanding of natural collisional processes.

Stress induced by the Mio-Pliocene Alpine collision in northern France

Abstract In most rocks, tectonic stress induces crystalline deformation, such as mechanical twinning. The inverse analysis of calcite twinning allows reconstruction of both directions and values of the paleostress field. The Etchecopar inverse method using calcite twinning has been improved in this paper, lowering the uncertainties on the calculated stress values. Calcite was sampled in the foreland of the western Alps, along a SE-NW section from the Jura Mountains to the Isle of Wight. The calcite twinning inversion has identified the successive Cenozoic tectonic events, named “Pyrenean” compression, “Oligocene” extension and “Alpine” compression. The distribution of the Mio-Pliocene Alpine orogenic stress was specified. This stress field varies in terms of stress regime, directions and values. The horizontal principal stress trends E-W in southern France, WNW in the centre, and NW in the North, which can be attributed to the Alpine indenter phenomenon. The tectonic stress regime roughly corresponds to a pure compression in the Jura and rapidly evolves to the NW to a strike-slip state of stress, then beyond the Paris basin’s centre to a perpendicular extension. Unlike the Pyrenean or Appalachian foreland stress, the Alpine differential stress does not significantly decrease from the Jura front to the far field (30 to 25 MPa). Moreover, stress values vary from one area to another, low in the Burgundy high, fractured and uprising during this tectonic event, and high in Paris basin centre, poorly fractured and subsiding during this event. Three possible explanations are proposed : variation in crust thickness, crustal buckling during the Mio-Pliocene, and pre-existing fractures.

Model-inspired interpretation of seismic structures in the Central Alps: Crustal wedging and buckling at mature stage of collision

Research Article| July 01, 2002 Model-inspired interpretation of seismic structures in the Central Alps: Crustal wedging and buckling at mature stage of collision Jean-Pierre Burg; Jean-Pierre Burg 1Geologisches Institut, ETH-Zentrum and Universität Zürich, Sonneggstrasse 5, CH-8092 Zürich, Switzerland Search for other works by this author on: GSW Google Scholar Dimitrios Sokoutis; Dimitrios Sokoutis 2Department of Geology and Physical Geography, School of Geology, Aristotle University of Thessaloniki, 540 06 Thessaloniki, Greece Search for other works by this author on: GSW Google Scholar Marco Bonini Marco Bonini 3Consiglio Nazionale delle Ricerche, Istituto di Geoscienze e Georisorse, Sezione di Firenze, via G. La Pira 4, 50121 Firenze, Italy Search for other works by this author on: GSW Google Scholar Geology (2002) 30 (7): 643–646. https://doi.org/10.1130/0091-7613(2002)030<0643:MIIOSS>2.0.CO;2 Article history received: 13 Nov 2001 rev-recd: 28 Feb 2002 accepted: 03 Mar 2002 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jean-Pierre Burg, Dimitrios Sokoutis, Marco Bonini; Model-inspired interpretation of seismic structures in the Central Alps: Crustal wedging and buckling at mature stage of collision. Geology 2002;; 30 (7): 643–646. doi: https://doi.org/10.1130/0091-7613(2002)030<0643:MIIOSS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Analogue models of continental convergence inspire a new interpretation of the deep-seismic profile across the Central Alps, the classical collision belt of Western Europe. We conclude that active mountain-building processes involve wedging and crustal buckling and that seismic information does not reflect subduction-related orogeny, but documents recent crustal shortening. We also infer that present-day subduction of the delaminated European mantle lithosphere takes place below the northern side of the mountain belt. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Decoupled flexure in the South Pyrenean Foreland

Complex subsidence patterns during the mid‐late Eocene of the easternmost South Pyrenean foreland are well explained by a decoupled flexure model in which upper crustal buckling is accommodated by ductile flow in the mid‐lower crust while, simultaneously and independently, the lower lithosphere flexes above a ductile asthenosphere. The resulting predicted subsidence values agree with observation to well within the estimated uncertainties. The resulting lithospheric effective elastic thickness (EET) estimate (10±3 km) is low but similar to values obtained in the South Pyrenean foreland by other authors. The separate EET obtained for the upper crust (1.5±0.8 km) also agrees with tentative values given by other workers.

Crustal structure across the San Andreas Fault, southern California from teleseismic converted waves

Crustal structure along a 140 km long profile across the San Andreas Fault (SAF) in southern California was imaged by stacking teleseismic P– S converted phases recorded by a dense, short-period seismic array. The crust/mantle discontinuity (Moho) is visible as a continuous feature at a depth around 30 km but is offset 6 to 8 km beneath the SAF. A small Moho disruption can also be seen under the Eastern California Shear Zone (ECSZ). These results suggest that the SAF and ECSZ extend through the entire crust. The Moho upwarp under the San Gabriel Mountains indicates that the mountain ranges were lifted en masse as a result of crustal buckling under horizontal compression.

The Demise of Sverdrup Basin: Late Cretaceous-Paleogene Sequence Stratigraphy and Forward Modeling

ABSTRACT Five third-order stratigraphic sequences comprising Upper Cretaceous-Paleogene successions on Ellesmere and Axel Heiberg islands (Kanguk Formation and Eureka Sound Group) record fundamental changes in the mechanisms of subsidence and the ultimate demise of Sverdrup Basin. Sequence I (Cenomanian-Maastrichtian) represents a continuation of typical Sverdrup sedimentation patterns (delta and associated facies), and long-lived, thermally controlled subsidence where sedimentation rates averaged 3 cm/ky. Relative fall of base level at the end of the Cretaceous resulted in n basinwide sub-Paleocene unconformity, below which some or all Maastrichtian strata were removed. This event coincided with changes in sea-floor spreading in Canada Basin and northern Labrador Sea, and rejuvenation of volc nism along the northern basin margin. Foredeep-like subsidence and sedimentation began in the Paleogene. Subsidence was caused by compression and crustal buckling associated with shortening between Greenland and Arctic North America rather than by tectonically emplaced vertical loads. Accordingly, Sequences 2 to 4 (Paleocene-Middle Eocene) record significant increases in subsidence and sedimentation rates in the basin. Deposition in the preorogenic Sverdrup Basin culminated with Sequence 4 (Late Paleocene-Middle Eocene), the basin being filled to sea level. Basin size, and sedimentation rates that averaged 15 cm/ky but sometimes were as high as 20-40 cm/ky, were greatest during deposition of Sequences 3 and 4. Syntectonic conglomerate appears locally in Early Eocene fault-b unded basins (Sequence 4--Otto Fiord and Emma Fiord). Nevertheless, the preorogenic basin survived as a subsiding entity until Middle Eocene time, despite the local deformation. Increased shortening and crustal failure during Middle Eocene time eventually fragmented the Sverdrup Basin into narrow, syntectonic intermontane basins (Sequence 5), marking its demise.

Periodic instabilities during compression or extension of the lithosphere 1. Deformation modes from an analytical perturbation method

We argue that the plastic rheology of the lithosphere, rather than its “recoverable” elastic properties, is responsible for the systematic development of periodic instabilities during compression or extension. We use a linear perturbation model with analytical solutions to calculate the instability modes for various rheologies. The growth of such periodic instabilities is enhanced by the highly nonlinear stress‐strain rheologies encountered in the brittle layers of the lithosphere. On the contrary, ductile layers, deforming according to high temperature creep flow laws, tend to inhibit these instabilities. For oceanic domains, we assume that the only brittle layer is the upper part of the lithosphere. In compression, the only valid instability is a buckling whose wavelength is around 4 times the thickness of the brittle layer. Calculated wavelengths and growth rates are consistent with observations available for the Indian Ocean. For continental domains, a reasonable assumption is the existence of two plastic layers, one in the upper crust, the other in the upper mantle, for Moho temperatures between 450°C and 600°C. In compression and extension, two instabilities develop a long wavelength instability involving the whole lithosphere (coupling mode) and a short wavelength instability involving the crust and controlled by the upper brittle layer (intrinsic crustal mode). In compression, the coupling mode is a whole‐lithosphere buckling, with a wavelength about 4 times the thickness of the active lithosphere (the two plastic layers plus the intermediate ductile layer). In extension, the coupling mode is a boudinage of opposite phase in the two plastic layers and a folding of the intermediate ductile layer. The intrinsic crustal mode is a crustal buckling in compression, crustal boudinage in extension. Neither deflects the Moho. The intrinsic crustal mode is favored by an increase in thermal gradient and by a decrease in strength of the ductile lower crust.

Instability of a Layer on a Half Space

Unstable deformations of an elastic or elastoplastic layer on an elastic or elastoplastic half space, are studied under compressive forces. Various combinations of material properties are considered, e.g., an elastic layer on an elastoplastic half space, elastoplastic layer on an elastic half space, etc. Both the flow and the total deformation plasticity models are used and the corresponding results compared. The results seem to have relevance to the problem of folding of geological formations and crustal buckling under tectonic stresses.

Seismic structure of the Transverse Ranges, California

Research Article| October 01, 1977 Seismic structure of the Transverse Ranges, California DAVID HADLEY; DAVID HADLEY 1Seismological Laboratory, California Institute of Technology, Pasadena, California 91125 Search for other works by this author on: GSW Google Scholar HIROO KANAMORI HIROO KANAMORI 1Seismological Laboratory, California Institute of Technology, Pasadena, California 91125 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1977) 88 (10): 1469–1478. https://doi.org/10.1130/0016-7606(1977)88<1469:SSOTTR>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation DAVID HADLEY, HIROO KANAMORI; Seismic structure of the Transverse Ranges, California. GSA Bulletin 1977;; 88 (10): 1469–1478. doi: https://doi.org/10.1130/0016-7606(1977)88<1469:SSOTTR>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Travel-time data obtained from both natural and artificial events occurring in southern California indicate a major, lateral crustal transition within the Transverse Range Province. The eastern crust is very similar to the adjacent Mojave region, where a crustal velocity of 6.2 km/sec is typically observed. The western ranges are dominated by an extensive 6.7 km/sec layer. Pn velocity beneath the western Mojave, Transverse Ranges, and northern Peninsular Ranges is 7.8 km/sec. The crustal thickness of these provinces is 30 to 35 km. The Transverse Ranges do not have a distinct crustal root. Unlike other provinces within southern California, the Transverse Ranges are underlain at a depth of 40 km by a refractor with a P-velocity of 8.3 km/sec. P-delays from a vertically incident, well-recorded teleseism suggest that this velocity anomaly extends to a depth of 100 km. These data indicate that this high-velocity, ridge-like structure is coincident with much of the areal extent of the geomorphic Transverse Ranges and is not offset by the San Andreas fault. Four hypotheses are advanced to explain the continuity of this feature across the plate boundary: (1) dynamic phase change; (2) a coincidental alignment of crust or mantle anomalies; (3) the litho-sphere is restricted to the crust; (4) the plate boundary at depth is displaced from the San Andreas fault at the surface. Within the context of the last model, we suggest the plate boundary at depth is at the eastern end of the velocity anomaly, in the vicinity of the active Helendale-Lenwood-Camprock faults. The regionally observed 7.8 km/sec layer is suggested as a zone of decoupling necessary to accommodate the horizontal shear that must result from the divergence of the crust and upper mantle plate boundaries. The geomorphic Transverse Ranges are viewed as crustal buckling caused by the enhanced coupling between the crust and upper mantle which is suggested by the locally thin, 7.8 km/sec layer. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Compression of floating elastic and viscous plates affected by gravity, a basis for discussing crustal buckling

The theory of buckling of floating elastic and viscous plates affected simultaneously by gravity and lateral compression is reviewed. The theoretical equations are verified by experiments with elastic rubber plates and viscous resin plates (viscosity 10 8–10 9 poises) floating on mercury or a solution of potassium-iodide. The assumption occasionally expressed by earth scientists that crustal buckling of geosynclinal dimensions is physically impossible is strongly supported by experiments and theory. Taking the known rheological properties of crustal rocks into account, one finds that troughs wide enough to function as geosynclines cannot possibly form by crustal buckling in response to lateral compression. There are at least two ways of showing the fallacy of the buckling model of geosynclinal formations: 1. (1) Introduction of the maximum strength of silicate rocks (4.10 9 dynes/cm 2) and the thickness of the crust (say 30 km) into buckling equations yields a maximum wavelength of 90 km, or 45 km as the maximum width of the troughs. This is too narrow to represent geosynclines. Consideration of the viscosity of the subcrust yields much shorter buckles. 2. (2) There is a certain relationship between the rate of buckling and the rate of uniform compressive strain in a surface layer under lateral compression. Low compressive stress and large layer thickness render the uniform shortening and thickening of the layer more important than the buckling. Thus controlled by the ultimate strength of a rock, there is a maximum thickness which a surface layer cannot exceed without completely masking the buckling by uniform compression. On this basis, the maximum thickness of a granite layer capable of buckling is a little above 1 km and the consequent length of the resulting buckles is less than 15 km. The conclusion is therefore that whereas lateral compression certainly may generate small and moderate buckling folds of layered rocks within a geosyncline, the crust as a whole is not capable of responding to lateral stress by buckling of geosynclinal dimensions.