Plate tectonic chain reaction constrained from noise in the Cretaceous Quiet Zone

2020 ◽  
Author(s):  
Derya Gürer ◽  
Roi Granot ◽  
Douwe J.J. van Hinsbergen
Keyword(s):  
Subduction Zones ◽  
Kinematic Model ◽  
Plate Boundary ◽  
Western Mediterranean ◽  
Plate Motion ◽  
Plate Boundaries ◽  
Plate Tectonic ◽  
Test Bed ◽  
Chain Reaction ◽  
Tectonic Plates

<p>The relative motions of the tectonic plates show remarkable variation throughout Earth’s history. Major changes in relative motion between the tectonic plates are traditionally viewed as spatially and temporally isolated events linked to forces acting on plate boundaries (i.e., formation of same-dip double subduction zones, changes in the strength of the boundary), or thought to be associated with mantle dynamics. A Cretaceous global plate reorganization event has been postulated to have affected all major plates. The Cretaceous ‘swing’ in Africa-Eurasia relative plate motion provides an ideal test-bed for assessing the temporal and spatial evolution of both relative plate motions and surrounding geological markers. Here we show a novel plate kinematic model for the closure of the Tethys Ocean by implementing intra-Cretaceous Quiet Zone time markers and combine the results with the geological constraints found along the convergent plate boundary. Our results allow to assess the order, causes and consequences of geological events and unravel a chain of tectonic events that set off with the onset of horizontally-forced double subduction ~105 Myr ago, followed by a 40 Myr long period of acceleration of the Africa relative to Eurasia that peaked at 80 Myr ago (at rates four times as high as previously predicted). This acceleration, which was likely caused by the pull of two same-dip subduction zones was followed by a sharp decrease in plate velocity, when double subduction terminated with ophiolite obduction onto the African margin. These tectonic forces acted on the eastern half of the Africa-Eurasia plate boundary, which led to counterclockwise rotation of Africa and sparked new subduction zones in the western Mediterranean region. Our analysis identifies the Cretaceous double subduction episode between Africa and Eurasia as a link in the global plate tectonic chain reaction and provides a dynamic view on plate reorganizations.</p>

Using geodynamic modeling to test plate tectonic scenarios of the Mediterranean-Alpine area

2020 ◽  
Author(s):  
Boris Kaus ◽  
Eline Le Breton ◽  
Georg Reuber ◽  
Christian Schuler
Keyword(s):  
Subduction Zones ◽  
Thermal Structure ◽  
Shear Zones ◽  
Western Mediterranean ◽  
Plate Motion ◽  
Plate Tectonic ◽  
Test Plate ◽  
Alpine Area ◽  
Tectonic Reconstruction ◽  
The Mediterranean

<p>Using geological and geophysical data, it is possible to reconstruct the past motion of tectonic plates involved in the Alpine orogeny and propose possible scenarios for their geological evolution. However, those scenarios have not yet been tested for geodynamic consistency.</p><p>Here, we perform 3D thermomechanical geodynamic simulations of the Mediterranean-Alpine area starting with a plate tectonic reconstruction at 20 Ma based on the work of Le Breton et al. (2017). The models include viscoelastoplastic rheologies and a free surface, and thus simulate the spontaneous occurrence of shear zones as well as the development of topography. Whereas some aspects of the tectonic reconstruction are well constrained (i.e. past position of the plates and subduction-collision fronts), many details such as the dip and length of the subducted plates, their thermal structure as well as their rheology, are unknown. The models are run forward in time to see to which extent they are consistent with the kinematic reconstructions. Perhaps unsurprisingly, our initial modelling attempts show a wide variety of behavior, including slab break off events and slab rollbacks in the wrong directions. Yet, in all cases tested so far, the model evolution does not reproduce the present-day geological setting, with Adria frequently moving too far towards the east and breaking apart internally, frequently no Alpine chain forming and in some cases new subduction zones developing within the Western Mediterranean that swallow Sardinia and Corsica.</p><p>Reproducing geological scenarios with thermomechanical geodynamic modelling thus requires substantial additional work, both from the modelling side (testing the effect of uncertain parameters on the behaviour of plates and subduction zones), as well as from the plate reconstruction side (assessing which parameters are well constrained and need to be reproduced).  Nevertheless, interesting insights can already be obtained from our models, and in our presentation, we will highlight some of the links between interacting subducting plates and plate motion.</p><p>Le Breton E, Handy MR, Molli G, Ustaszewski K (2017) Post-20 Ma Motion of the Adriatic Plate: New Constraints From Surrounding Orogens and Implications for Crust-Mantle Decoupling. Tectonics 36:3135–3154. doi: 10.1002/2016TC004443</p><div> <div> <div> </div> </div> </div>

scholarly journals Pattern of seismic deformation in the Western Mediterranean

1999 ◽  
Vol 42 (1) ◽  
Author(s):  
S. Pondrelli
Keyword(s):  
Moment Tensor ◽  
Plate Boundary ◽  
Eastern Alps ◽  
Western Mediterranean ◽  
Plate Motion ◽  
Moment Tensors ◽  
Motion Models ◽  
Strain Pattern ◽  
Seismological Data ◽  
Seismic Deformation

The seismic deformation of the Western Mediterranean was studied with the aim of defining the strain pattern that characterizes the Africa-Eurasia plate boundary in this area. Within different sections along the boundary the cumulative moment tensor was computed over 90 years of seismological data. The results were compared with NUVELlA plate motion model and geodetic data. A stable agreement was found along Northern Africa to Sicily, where only Africa and Eurasia plates are involved. In this zone it is evident that changes in the strike of the boundary correspond to variations in the prevailing geometry of deformation, tectonic features and in the percentage of seismic with respect to total expected deformation. The geometry of deformation of periadriatic sections (Central to Southern Apennines, Eastern Alps and the Eastern Adriatic area) agrees well with VLBI measurements and with regional geological features. Seismicity seems to account for low rates, from 3% to 31%, of total expected deformation. Only in the Sicily Strait, characterized by extensional to strike slip deformation, does the ratio reach a higher value (79%). If the amount of deformation deduced from seismicity seems low, because 90 years are probably not representative of the recurrence seismic cycle of the Western Mediterranean, the strain pattern we obtain from cumulative moment tensors is more representative of the kinematics of this area than global plate motion models and better identifies lower scale geodynamic features.

scholarly journals Current Plate Motions

1988 ◽  
Vol 129 ◽  
pp. 351-352
Author(s):  
Richard Gordon ◽  
Charles Demets ◽  
Seth Stein ◽  
Don Argus ◽  
Dale Woods
Keyword(s):  
Subduction Zones ◽  
Continental Drift ◽  
Geophysical Data ◽  
Plate Motion ◽  
Plate Boundaries ◽  
Transform Faults ◽  
Plate Motions ◽  
Motion Data ◽  
Motion Models ◽  
Self Consistent

The standard against which VLBI measurements of continental drift and plate motions are compared are self-consistent global models of “present-day” plate motions determined from geophysical data: marine magnetic anomalies at oceanic spreading centers, azimuths of transform faults, and orientations of earthquake slip vectors on transform faults and at subduction zones. Past global plate motion models have defined regions where the assumption that plates behave rigidly has apparently lead to systematic misfits, sometimes exceeding 10 mm/yr, of plate motion data. Here, we present some of the results from NUVEL-1, a new, self-consistent global model of present-day relative plate motions determined from a compilation and analysis of existing and new geophysical data. These data and new techniques have allowed us to eliminate nearly all statistically significant systematic misfits identified by earlier models, suggesting that the rigid-plate assumption is an excellent approximation when plate motions are averaged over several million years. Beside improving estimates of the motion on previously identified plate boundaries, we have also identified and determined motions on other boundaries whose subtle morphologies, lack of seismicity, and very slow (< 10 mm/yr) relative motions have made them difficult to detect. Here we focus on the application of VLBI measurements to help resolve plate tectonic problems and then briefly outline our results for Pacific-North America motion and plate motions in the Indian Ocean.

An analytical model concerning the possible initiation of subduction between the India and Africa plates, caused by the Morondova plume

2020 ◽  
Author(s):  
Bernhard Steinberger ◽  
Douwe van Hinsbergen
Keyword(s):  
Subduction Zones ◽  
Plate Tectonics ◽  
Eastern Mediterranean ◽  
Plate Boundary ◽  
Plate Motion ◽  
Mantle Flow ◽  
Plate Motions ◽  
Subduction Initiation ◽  
Euler Pole ◽  
Geodynamic Processes

&lt;p&gt;Identifying the geodynamic processes that trigger the formation of new subduction zones is key to understand what keeps the plate tectonic cycle going, and how plate tectonics once started. Here we discuss the possibility of plume-induced subduction initiation. Previously, our numerical modeling revealed that mantle upwelling and radial push induced by plume rise may trigger plate motion change, and plate divergence as much as 15-20 My prior to LIP eruption. Here we show that, depending on the geometry of plates, the distribution of cratonic keels and where the plume rises, it may also cause a plate rotation around a pole that is located close to the same plate boundary where the plume head impinges: If that occurs near one end of the plate boundary, an Euler pole of the rotation may form along that plate boundary, with extension on one side, and convergence on the other.&amp;#160; This concept is applied to the India-Africa plate boundary and the Morondova plume, which erupted around 90 Ma, but may have influenced plate motions as early as 105-110 Ma. If there is negligible friction, i.e. there is a pre-existing weak plate boundary, we estimate that the total amount of convergence generated in the northern part of the India-Africa plate boundary can exceed 100 km, which is widely thought to be sufficient to initiate forced, self-sustaining subduction. This may especially occur if the India continental craton acts like an &amp;#8220;anchor&amp;#8221; causing a comparatively southern location of the rotation pole of the India plate. Geology and paleomagnetism-based reconstructions of subduction initiation below ophiolites from Pakistan, through Oman, to the eastern Mediterranean reveal that E-W convergence around 105 Ma caused forced subduction initiation, and we tentatively postulate that this is triggered by Morondova plume head rise. Whether the timing of this convergence is appropriate to match observations on subduction initiation as early as 105 Ma depends on the timing of plume head arrival, which may predate eruption of the earliest volcanics. It also depends on whether a plume head already can exert substantial torque on the plate while it is still rising &amp;#8211; for example, if the plate is coupled to the induced mantle flow by a thick craton.&lt;/p&gt;

scholarly journals Tectonic tremor and deep slow slip on the Alpine Fault

2021 ◽  
Author(s):  
A Wech ◽  
C Boese ◽  
Timothy Stern ◽  
John Townend
Keyword(s):  
Lower Crust ◽  
Subduction Zones ◽  
Plate Boundary ◽  
P Wave ◽  
Plate Boundaries ◽  
Depth Range ◽  
Slow Slip ◽  
High Attenuation ◽  
Alpine Fault ◽  
Tectonic Tremor

Tectonic tremor is characterized by persistent, low-frequency seismic energy seen at major plate boundaries. Although predominantly associated with subduction zones, tremor also occurs along the deep extension of the strike-slip San Andreas Fault. Here we present the first observations of tectonic tremor along New Zealand's Alpine Fault, a major transform boundary that is late in its earthquake cycle. We report tectonic tremor that occurred on the central section of the Alpine Fault on 12days between March 2009 and October 2011. Tremor hypocenters concentrate in the lower crust at the downdip projection of the Alpine Fault; coincide with a zone of high P-wave attenuation (low Q p) and bright seismic reflections; occur in the 25-45km depth range, below the seismogenic zone; and may define the deep plate boundary structure extending through the lower crust and into the upper mantle. We infer this tremor to represent slow slip on the deep extent of the Alpine Fault in a fluid-rich region marked by high attenuation and reflectivity. These observations provide the first indication of present-day displacement on the lower crustal portion of the Australia-Pacific transform plate boundary. © Copyright 2012 by the American Geophysical Union.

Investigating the plate kinematics of continental blocks and their role on the deformation experienced along the Iberia-Eurasia plate boundary using deformable plate tectonic models

2021 ◽  
Author(s):  
Michael King ◽  
Kim Welford ◽  
Patricia Cadenas ◽  
Julie Tugend
Keyword(s):  
Plate Boundary ◽  
Magnetic Anomalies ◽  
Collective Impact ◽  
Plate Tectonic ◽  
Alpine Orogeny ◽  
Tectonic Plates ◽  
Plate Models ◽  
Plate Reconstructions ◽  
Kinematic Models ◽  
Plate Kinematics

&lt;p&gt;The kinematics of the Iberian plate during Mesozoic extension and subsequent Alpine compression and their implications on the partitioning of strain experienced across the Iberia-Europe plate boundary continue to be a subject of scientific interest, and debate. To date, the majority of plate tectonic models only consider the motion of rigid tectonic plates. In addition, the lack of consideration for the kinematics of intra-continental domains and intervening continental blocks in-between has led to numerous discrepancies between rigid plate kinematic models of Iberia, based mainly on tight-fit reconstruction of M-series magnetic anomalies, and their ability to reconcile geological and geophysical observations. To address these discrepancies, deformable plate tectonic models constrained by previous plate reconstructions, geological, and geophysical studies are built using the GPlates software to study the evolution of deformation experienced along the Iberia-Eurasia plate boundary from the Triassic to present day. These deformable plate models consider the kinematics of small intra-continental blocks such as the Landes High and Ebro Block situated between large tectonic plates, their interplay with pre-existing structural trends, and the collective impact of these phenomena on the deformation experienced during Mesozoic rifting and Alpine compressional re-activation along the Iberia-European plate boundary. Preliminary results suggest that the independent kinematics of the Landes High played a key role on the distribution of oblique extension between different rift arms and resultant deformation within the Bay of Biscay. Within the Pyrenean realm, deformation experienced prior to and during the Alpine Orogeny was more largely controlled by the interplay between the Ebro Block kinematics and rift segmentation induced by the orientation of inherited trends.&lt;/p&gt;

Emergence of plate tectonic during the Archean: insights from 3D numerical modelling.

2021 ◽  
Author(s):  
Andrea Piccolo ◽  
Boris Kaus ◽  
Richard White ◽  
Nicolas Arndt ◽  
Nicolas Riel
Keyword(s):  
Phase Transitions ◽  
Subduction Zones ◽  
Plate Tectonics ◽  
Large Scale ◽  
Potential Temperature ◽  
Secular Change ◽  
Plate Boundaries ◽  
Plate Tectonic ◽  
Subduction Initiation ◽  
The Earth

&lt;p&gt;In the plate tectonic convection regime, the external lid is subdivided into discrete plates that move independently. Although it is known that the system of plates is mainly dominated by slab-pull forces, it is not yet clear how, when and why plate tectonics became the dominant geodynamic process in our planet. It could have started during the Meso-Archean (3.0-2.9 Ga). However, it is difficult to conceive a subduction driven system at the high mantle potential temperatures (&lt;strong&gt;Tp&lt;/strong&gt;) that are thought to have existed around that time, because &lt;strong&gt;Tp&lt;/strong&gt; controls the thickness and the strength of the compositional lithosphere making subduction unlikely. In recent years, however, a credible solution to the problem of subduction initiation during the Archean has been advanced, invoking a plume-induced subduction mechanism[1] that seems able to generate plate-tectonic like behaviour to first order. However, it has not yet been demonstrated how these tectonic processes interact with each other, and whether they are able to eventually propagate to larger scale subduction zones.&lt;/p&gt;&lt;p&gt;The Archean Eon was characterized by a high &lt;strong&gt;Tp&lt;/strong&gt;[2]&lt;strong&gt;, &lt;/strong&gt;which generates weaker plates, and a thick and chemically buoyant lithosphere. In these conditions, slab pull forces are inefficient, and most likely unable to be transmitted within the plate. Therefore, plume-related proto-plate tectonic cells may not have been able to interact with each other or showed a different interaction as a function of mantle potential temperature and composition of the lithosphere. Moreover, due to secular change of &lt;strong&gt;Tp, &lt;/strong&gt;the dynamics may change with time. In order to understand the complex interaction between these tectonic seeds it is necessary to undertake large scale 3D numerical simulations, incorporating the most relevant phase transitions and able to handle complex constitutive rheological model.&lt;/p&gt;&lt;p&gt;Here, we investigate the effects of the composition and &lt;strong&gt;Tp &lt;/strong&gt;independently to understand the potential implications of the interaction of plume-induced subduction initiation. We employ a finite difference visco-elasto-plastic thermal petrological code using a large-scale domain (10000 x 10000 x 1000 km along x, y and z directions) and incorporating the most relevant petrological phase transitions. We prescribed two oceanic plateaus bounded by subduction zones and we let the negative buoyancy and plume-push forces evolve spontaneously. The paramount question that we aim to answer is whether these configurations allow the generation of stable plate boundaries. The models will also investigate whether the presence of continental terrain helps to generate plate-like features and whether the processes are strong enough to generate new continental terrains&amp;#160;&lt;span&gt;or assemble them &lt;/span&gt;&lt;/p&gt;&lt;p&gt;.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;[1]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; T. V. Gerya, R. J. Stern, M. Baes, S. V. Sobolev, and S. A. Whattam, &amp;#8220;Plate tectonics on the Earth triggered by plume-induced subduction initiation,&amp;#8221; Nature, vol. 527, no. 7577, pp. 221&amp;#8211;225, 2015.&lt;/p&gt;&lt;p&gt;[2]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; C. T. Herzberg, K. C. Condie, and J. Korenaga, &amp;#8220;Thermal history of the Earth and its petrological expression,&amp;#8221; Earth Planet. Sci. Lett., vol. 292, no. 1&amp;#8211;2, pp. 79&amp;#8211;88, 2010.&lt;/p&gt;&lt;p&gt;[3]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; R. M. Palin, M. Santosh, W. Cao, S.-S. Li, D. Hern&amp;#225;ndez-Uribe, and A. Parsons, &amp;#8220;Secular metamorphic change and the onset of plate tectonics,&amp;#8221; Earth-Science Rev., p. 103172, 2020.&lt;/p&gt;

Plate tectonic modelling: review and perspectives

2018 ◽  
Vol 156 (2) ◽  
pp. 208-241 ◽  
Author(s):  
CHRISTIAN VÉRARD
Keyword(s):  
Plate Boundaries ◽  
Dual Control ◽  
Plate Tectonic ◽  
Joint Effort ◽  
Tectonic Plate ◽  
Deep Time ◽  
Tectonic Plates ◽  
Control Approach ◽  
New Frontier ◽  
Tectonic Boundaries

AbstractSince the 1970s, numerous global plate tectonic models have been proposed to reconstruct the Earth's evolution through deep time. The reconstructions have proven immensely useful for the scientific community. However, we are now at a time when plate tectonic models must take a new step forward. There are two types of reconstructions: those using a ‘single control’ approach and those with a ‘dual control’ approach. Models using the ‘single control’ approach compile quantitative and/or semi-quantitative data from the present-day world and transfer them to the chosen time slices back in time. The reconstructions focus therefore on the position of tectonic elements but may ignore (partially or entirely) tectonic plates and in particular closed tectonic plate boundaries. For the readers, continents seem to float on the Earth's surface. Hence, the resulting maps look closer to what Alfred Wegener did in the early twentieth century and confuse many people, particularly the general public. With the ‘dual control’ approach, not only are data from the present-day world transferred back to the chosen time slices, but closed plate tectonic boundaries are defined iteratively from one reconstruction to the next. Thus, reconstructions benefit from the wealth of the plate tectonic theory. They are physically coherent and are suited to the new frontier of global reconstruction: the coupling of plate tectonic models with other global models. A joint effort of the whole community of geosciences will surely be necessary to develop the next generation of plate tectonic models.

scholarly journals Phanerozoic paleogeographic, plate tectonic and paleoclimatic reconstructions

1992 ◽  
Vol 6 ◽  
pp. 263-263 ◽  
Author(s):  
Christopher R. Scotese
Keyword(s):  
General Circulation ◽  
Subduction Zones ◽  
Coastal Upwelling ◽  
Hot Spot ◽  
Circulation Model ◽  
Time Interval ◽  
Plate Boundaries ◽  
Plate Tectonic ◽  
Prevailing Wind Direction ◽  
Event Stratigraphy

In 1913, in the concluding remarks to his two volume compendium, Principles of Stratigraphy, Amadeus Grabau wrote, “When the science of Stratigraphy has developed so that its basis is no longer purely or chiefly paleontological, and when the sciences of Lithogenisis and Orogenesis … are given their due share in the comprehensive investigation of the history of the earth, then we may hope that Paleogeography, the youthful daughter science of Stratigraphy will have attained unto that stature that will make it the crowning attraction to the student of earth history.” It has taken nearly 80 years for Grabau's vision to be realized. The fruits of the plate tectonic revolution combined with our new understanding of global eustasy and event stratigraphy, make it now possible to map the changing geography of the earth's surface with unparalleled detail and accuracy.In this poster session, we present 28 paleogeographic maps illustrating the changing configuration of mountains, land, shallow seas, and deep ocean basins during the Phanerozoic. The plate boundaries (spreading ridges, subduction zones, and transform faults) that were active during each time interval are also shown. For the Mesozoic and Cenozoic these plate boundaries are based on a synthesis of linear magnetic anomaly data and fracture zone locations compiled by PALEOMAP Project (International Lithosphere Program). The Mesozoic and Cenozoic orientation of the continents relative to the Earth's axis of rotation has been determined using a combination of paleomagnetic data and hot spot tracks. The location of Paleozoic plate boundaries, though speculative, is based evidence of past subduction and inferred sea floor spreading. The relative longitudinal positions of the continents and the width of the intervening Paleozoic oceans have been adjusted to best explain changing biogeographic and paleoclimatic patterns.The land, sea and mountain distributions portrayed on these 28 paleogeographic reconstructions have been used as input for a series of computer simulations of paleoclimate. The paleoclimatic model, which was developed by C.R. Scotese and M. I. Ross, uses the latitudinal distribution of land and sea, as well as the orientation of ancient mountain belts to predict the distr ibution of high and low pressure cells, prevailing wind direction, relative wetness/dryness, as well as zones of coastal upwelling. This model, which takes a simple parametric approach, makes predictions which are similar to the more robust General Circulation Model (GCM), but requires far less computer resources.

scholarly journals Oblique rifting: the rule, not the exception

2018 ◽  
Author(s):  
Sascha Brune ◽  
Simon E. Willliams ◽  
R. Dietmar Müller
Keyword(s):  
Gulf Of California ◽  
Plate Boundary ◽  
Strain Analysis ◽  
Dominant Mode ◽  
Plate Boundaries ◽  
Tectonic Plates ◽  
Relative Extension ◽  
Reconstruction Software ◽  
Oblique Rifting ◽  
Extension Direction

Abstract. Movements of tectonic plates often induce oblique deformation at divergent plate boundaries. This is in striking contrast with traditional conceptual models of rifting and rifted margin formation, which often assume 2D deformation where the rift velocity is oriented perpendicular to the plate boundary. Here we quantify the validity of this assumption by analysing the kinematics of major continent-scale rift systems in a global plate tectonic reconstruction from the onset of Pangea breakup until present-day. We evaluate rift obliquity by joint examination of relative extension velocity and local rift trend using the script-based plate reconstruction software pyGPlates. Our results show that the global mean rift obliquity amounts to 34° with a standard deviation of 24°, using the convention that the angle of obliquity is spanned by extension direction and rift trend normal. We find that more than ~ 70 % of all rift segments exceeded an obliquity of 20° demonstrating that oblique rifting should be considered the rule, not the exception. In many cases, rift obliquity and extension velocity increase during rift evolution (e.g. Australia-Antarctica, Gulf of California, South Atlantic, India-Antarctica), which suggests an underlying geodynamic correlation via obliquity-dependent rift strength. Oblique rifting produces 3D stress and strain fields that cannot be accounted for in simplified 2D plane strain analysis. We therefore highlight the importance of 3D approaches in modelling, surveying, and interpretation of most rift segments on Earth where oblique rifting is the dominant mode of deformation.

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