scholarly journals The inception of plate tectonics: a record of failure

2018 ◽  
Vol 376 (2132) ◽  
pp. 20170414 ◽  
Author(s):  
Craig O'Neill ◽  
Simon Turner ◽  
Tracy Rushmer
Keyword(s):  
Subduction Zones ◽  
Plate Tectonics ◽  
Initial Conditions ◽  
Numerical Models ◽  
Early History ◽  
Early Earth ◽  
Strong Nonlinearity ◽  
Plate Tectonic ◽  
Geological Record ◽  
History Of

The development of plate tectonics from a pre-plate tectonics regime requires both the initiation of subduction and the development of nascent subduction zones into long-lived contiguous features. Subduction itself has been shown to be sensitive to system parameters such as thermal state and the specific rheology. While generally it has been shown that cold-interior high-Rayleigh-number convection (such as on the Earth today) favours plates and subduction, due to the ability of the interior stresses to couple with the lid, a given system may or may not have plate tectonics depending on its initial conditions. This has led to the idea that there is a strong history dependence to tectonic evolution—and the details of tectonic transitions, including whether they even occur, may depend on the early history of a planet. However, intrinsic convective stresses are not the only dynamic drivers of early planetary evolution. Early planetary geological evolution is dominated by volcanic processes and impacting. These have rarely been considered in thermal evolution models. Recent models exploring the details of plate tectonic initiation have explored the effect of strong thermal plumes or large impacts on surface tectonism, and found that these ‘primary drivers’ can initiate subduction, and, in some cases, over-ride the initial state of the planet. The corollary of this, of course, is that, in the absence of such ongoing drivers, existing or incipient subduction systems under early Earth conditions might fail. The only detailed planetary record we have of this development comes from Earth, and is restricted by the limited geological record of its earliest history. Many recent estimates have suggested an origin of plate tectonics at approximately 3.0 Ga, inferring a monotonically increasing transition from pre-plates, through subduction initiation, to continuous subduction and a modern plate tectonic regime around that time. However, both numerical modelling and the geological record itself suggest a strong nonlinearity in the dynamics of the transition, and it has been noted that the early history of Archaean greenstone belts and trondhjemite–tonalite–granodiorite record many instances of failed subduction. Here, we explore the history of subduction failure on the early Earth, and couple these with insights from numerical models of the geodynamic regime at the time. This article is part of a discussion meeting issue ‘Earth dynamics and the development of plate tectonics'.

scholarly journals Mafic Archean continental crust prohibited exhumation of orogenic UHP eclogite

2021 ◽  
Author(s):  
Richard Palin ◽  
James Moore ◽  
Zeming Zhang ◽  
Guangyu Huang
Keyword(s):  
Continental Crust ◽  
Plate Tectonics ◽  
Ultrahigh Pressure ◽  
Global Ocean ◽  
Secular Change ◽  
Early Earth ◽  
Low Density ◽  
Geological Record ◽  
Point Of No Return ◽  
Negatively Buoyant

Abstract The absence of ultrahigh pressure (UHP) orogenic eclogite in the geological record older than c. 0.6 Ga is problematic for evidence of subduction having begun on Earth during the Archean (4.0–2.5 Ga). Many eclogites in Phanerozoic and Proterozoic terranes occur as mafic boudins encased within low-density felsic crust, which provides positive buoyancy during subduction; however, recent geochemical proxy analysis shows that Archean continental crust was more mafic than previously thought. Here, we show via petrological modelling that secular change in the composition of upper continental crust (UCC) would make Archean continental terranes negatively buoyant in the mantle before reaching UHP conditions. Subducted or delaminated Archean continental crust passes a point of no return during metamorphism in the mantle prior to the stabilization of coesite, while Proterozoic and Phanerozoic terranes remain positively buoyant at these depths. UHP orogenic eclogite may thus readily have formed on the Archean Earth, but could not have been exhumed, weakening arguments for a Neoproterozoic onset of subduction and plate tectonics. Further, isostatic balance calculations for more mafic Archean continents indicate that the early Earth was covered by a global ocean over 1 kilometre deep.

scholarly journals A REVIEW OF EARLY PERMIAN (300–270 MA) MAGMATISM IN EASTERN KAZAKHSTAN AND IMPLICATIONS FOR PLATE TECTONICS AND PLUME INTERPLAY

2019 ◽  
Vol 10 (1) ◽  
pp. 79-99 ◽  
Author(s):  
S. V. Khromykh ◽  
P. D. Kotler ◽  
A. E. Izokh ◽  
N. N. Kruk
Keyword(s):  
Plate Tectonics ◽  
Granitic Rocks ◽  
Plate Tectonic ◽  
Early Permian ◽  
Structural Framework ◽  
Short Time Span ◽  
Lithospheric Extension ◽  
History Of ◽  
The Impact ◽  
Eastern Kazakhstan

The history of the Central Asian Orogenic Belt (CAOB) was marked by several major events of magmatism which produced large volumes of volcanic and intrusive (mafic-ultramafic and granitic) rocks within a relatively short time span (30–40 Ma) over a vast area. The magmatic activity postdated the orogenic stages of accretionary-collisional belts in Central Asia and likely resulted from the impact of mantle plumes that formed Large Igneous Provinces (LIPs). The formation of the Tarim–South Mongolia LIP at 300–270 Ma is the best known among the major Permian events of basaltic and granitic magmatism. Early Permian igneous rocks (volcanic, subvolcanic and intrusive suites that vary from ultramafic to felsic compositions) of the same age range (300 to 270 Ma) have been recently found also in Eastern Kazakhstan, within the late Paleozoic Altai collisional system. The compositions and ages of the rocks suggest that the Eastern Kazakhstan magmatism was the northward expansion of the Tarim LIP. The spread of the Tarim LIP was apparently facilitated by lithospheric extension after the Siberia-Kazakhstan collision. The extension led to rheological weakening of the lithosphere whereby deep mantle melts could penetrate to shallower depths. The early Permian history of Eastern Kazakhstan was controlled by the interplay of plate tectonic and plume processes: plate-tectonic accretion and collision formed the structural framework, and the Tarim mantle plume was a heat source maintaining voluminous magma generation.

The Early History of Atmospheric Oxygen: Biological Evidence

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Atmospheric Oxygen ◽  
Early History ◽  
Early Earth ◽  
Living Matter ◽  
Free Oxygen ◽  
Geologic Time ◽  
Surrounding Environment ◽  
History Of ◽  
Magnum Opus ◽  
Chemical Influence

This chapter discusses the history of atmospheric oxygen through geologic time. One of the giants in this discussion is Vladimir Vernadsky 1863–1945), a Ukranian mineralogist turned geochemist and visionary thinker. In 1926 he published his magnum opus The Biosphere, in which he systemically explored how life works as a geological force. One subject he touched upon was the history of atmospheric oxygen. He initiated this discussion by stating that in all geological periods, the chemical influence of living matter on the surrounding environment has not changed significantly. He concluded that the phenomena of superficial weathering clearly show that free oxygen played the same role in the Archean Era that it plays now. The chapter then explores early Earth biology, focusing on signs of cyanobacteria, without which oxygen could not have accumulated into the atmosphere.

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

<p>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 (<strong>Tp</strong>) that are thought to have existed around that time, because <strong>Tp</strong> 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.</p><p>The Archean Eon was characterized by a high <strong>Tp</strong>[2]<strong>, </strong>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 <strong>Tp, </strong>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.</p><p>Here, we investigate the effects of the composition and <strong>Tp </strong>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 <span>or assemble them </span></p><p>.</p><p> </p><p>[1]       T. V. Gerya, R. J. Stern, M. Baes, S. V. Sobolev, and S. A. Whattam, “Plate tectonics on the Earth triggered by plume-induced subduction initiation,” Nature, vol. 527, no. 7577, pp. 221–225, 2015.</p><p>[2]       C. T. Herzberg, K. C. Condie, and J. Korenaga, “Thermal history of the Earth and its petrological expression,” Earth Planet. Sci. Lett., vol. 292, no. 1–2, pp. 79–88, 2010.</p><p>[3]       R. M. Palin, M. Santosh, W. Cao, S.-S. Li, D. Hernández-Uribe, and A. Parsons, “Secular metamorphic change and the onset of plate tectonics,” Earth-Science Rev., p. 103172, 2020.</p>

Continental Drift—The Road to Plate Tectonics

2004 ◽  
Author(s):  
John J. W. Rogers ◽  
M. Santosh
Keyword(s):  
World War I ◽  
Plate Tectonics ◽  
Continental Drift ◽  
Early History ◽  
World War ◽  
The Road ◽  
The Earth ◽  
Before And After ◽  
History Of ◽  
The University

Alfred Wegener never set out to be a geologist. With an education in meteorology and astronomy, his career seemed clear when he was appointed Lecturer in those subjects at the University of Marburg, Germany. It wasn’t until 1912, when Wegener was 32, that he published a paper titled “Die Entstehung der Kontinente” (The origin of the continents) in a recently founded journal called Geologische Rundschau. This meteorologist had just fired the opening shot in a revolution that would change the way that geologists thought about the earth. In a series of publications and talks both before and after World War I, Wegener pressed the idea that continents moved around the earth independently of each other and that the present continents resulted from the splitting of a large landmass (we now call it a “supercontinent”) that previously contained all of the world’s continents. After splitting, they moved to their current positions, closing oceans in front of them and opening new oceans behind them. Wegener and his supporters referred to this process as “continental drift.” The proposal that continents moved around the earth led to a series of investigations and ideas that occupied much of the 20th century. They are now grouped as a set of concepts known as “plate tectonics.” We begin this chapter with an investigation of the history of this development, starting with ideas that preceded Wegener’s proposal. This is followed by a section that describes the reactions of different geologists to the idea of continental drift, including some comments that demonstrate the rancorous nature of the debate. The next section discusses developments between Wegener’s proposal and 1960, when Harry Hess suggested that the history of modern ocean basins is consistent with the concept of drifting continents. We finish the chapter with a brief description of seafloor spreading and leave a survey of plate tectonics to chapter 2. Although Wegener is credited with first proposing continental drift, some tenuous suggestions had already been made. We summarize some of this early history from LeGrand (1988).

Is Venus an analogue for Proterozoic Earth?

2021 ◽  
Author(s):  
Richard Ghail
Keyword(s):  
Subduction Zones ◽  
Plate Tectonics ◽  
High Surface ◽  
Global Network ◽  
Evolutionary Stage ◽  
Plate Tectonic ◽  
Spreading Ridges ◽  
Igneous Provinces ◽  
Detachment Layer ◽  
High Surface Temperature

<p>Venus is our most Earth-like twin, from a geological standpoint, but lacks Earth-like plate tectonics. Its lower mean density implies a smaller core and relatively large mantle, which combined with the inhibited cooling effected by its high surface temperature, suggests that Venus today may be at an earlier evolutionary stage than Earth. Geologically, a global network of rifts and corona chains (e.g. Parga Chasma) indicate subsurface, plate tectonic-like, spreading ridges below a crustal detachment layer, but there are no obvious corresponding subduction zones. Subduction has been inferred locally at a few large corona (e.g. Artemis) but only in relation to specific plumes, not global plate tectonics. Elsewhere there is evidence for numerous large igneous provinces and perhaps an even larger Overturn Upwelling Zones (OUZO) event at Lada Terra. These features suggest a planet in transition from an Archaean-like regime dominated by instability and overturns, towards a more stable plate tectonic regime: i.e. a planet analogous to the early Proterozoic Earth.</p>

Eoarchean formation of the Isua supracrustal belt

2020 ◽  
Author(s):  
A Alexander G Webb ◽  
Thomas Müller ◽  
Jiawei Zuo ◽  
Peter Haproff ◽  
Anthony Ramírez-Salazar
Keyword(s):  
Plate Tectonics ◽  
Multiple Scales ◽  
Early Earth ◽  
Plate Tectonic ◽  
Mantle Dynamics ◽  
Change Models ◽  
Fine Grained ◽  
Tectonic Events ◽  
Supracrustal Belt ◽  
Major Shift

<p>A major shift in Earth’s crustal generation processes at ~3.2 to 2.5 Ga has been inferred from mineralogical, geological, and geochemical records, particularly those recorded by fine-grained sediments and zircon crystals. The most common hypothesis to explain this shift is the onset of plate tectonic recycling following some form of hot stagnant lid geodynamics. However, all prior detailed geologic studies of our best-preserved Eoarchean terrane, the ~3.85 - 3.60 Ga Isua supracrustal belt of SW Greenland, interpret this site to record terrane collision within the context of plate tectonics. This represents a significant counterweight to the assumption underpinning the ~3 Ga tectonic-mode-change models, i.e., the idea that early Earth’s record is broadly representative. The Isua belt is divided into ~3.8 and ~3.7 Ga halves, and these have been interpreted as plate fragments which collided by ~3.6 Ga. Here, we examine the evidence used to support plate tectonic interpretations, focusing on 1) reanalysis of prior geochronological results and associated cross-cutting relationships which have previously been interpreted to record as many as eight tectonic events, and 2) new field observations leading to reinterpretation of basic structural relationships. Simpler interpretations of the geochronological and deformation data are viable: the belt may have experienced nearly homogeneous metamorphic conditions and strain during a single deformation event prior to intrusion of ~3.5 Ga mafic dikes. Curtain and sheath folds occur at multiple scales throughout the belt, with the entire belt potentially representing Earth’s largest a-type fold. We propose a new model: two cycles of volcanic burial and resultant melting and TTG intrusion produced first the ~3.8 Ga rocks and then the ~3.7 Ga rocks above, after which the whole belt was deformed and thinned in a shear zone, producing the multi-scale a-type folding patterns. The Eoarchean assembly of the Isua supracrustal belt is therefore most simply explained by vertical-stacking volcanic and instrusive processes followed by a single shearing event. In combination with well-preserved Paleoarchean terranes, these rocks record the waning downward advection of lithosphere inherent in volcanism-dominated heat-pipe tectonic models for early Earth. These interpretations are consistent with recent findings that early crust-mantle dynamics are remarkably similar across the solar system’s terrestrial bodies.</p>

The role of intrusive magmatism in shaping Venus’ present-day crust and its age distribution

2020 ◽  
Author(s):  
Sruthi Uppalapati ◽  
Tobias Rolf ◽  
Stephanie Werner
Keyword(s):  
Mantle Convection ◽  
Plate Tectonics ◽  
Numerical Models ◽  
Age Distribution ◽  
Crustal Thickness ◽  
Dominant Mode ◽  
Age Variations ◽  
Spherical Annulus ◽  
Crater Counting ◽  
History Of

<p>In its bulk properties, Venus appears similar to Earth, but both planets have developed substantially different geodynamic regimes. Earth has plate tectonics with a continuously renewed surface and its crustal distribution is very dichotomous in composition, thickness, and age. Venus, on the other hand, presently displays a period of a stagnant-lid regime, which may or may not was interrupted by catastrophic events of tectonic recycling during its history. Venus’ crustal thickness is not well constrained, but likely thicker than Earth’s oceanic crust; pronounced crustal dichotomy may be possible but evidence needs yet to be found. The age of the crust appears rather uniform, which traditionally has been taken as evidence that an episodic overturn must have taken place. However, recent arguments have challenged the episodic overturn hypothesis and favor a more continuous stagnant lid on Venus.</p><p> </p><p>To resolve the problem of Venus’ geodynamic regime understanding the generation of Venus’ crust in a dynamic context that also considers the underlying mantle is necessary. This can be achieved using numerical models of mantle convection tailored to Venus, which include the basic complexities of planetary mantle convection in terms of effective rheology, mineralogy and melting processes. Still, previous models have essentially failed to predict the thickness and age characteristics of Venus’ crust. One possible reason is that these models only considered extrusive volcanism, which renews the surface directly, while intrusive magmatism does not. Yet, intrusion seems the dominant mode of magmatism at least on Earth, so we investigate its influence in our model and evaluate whether this ingredient is key to predict Venus’ crustal characteristics.</p><p> </p><p>Using the code StagYY, we compute a suite of mantle convection models in 2D spherical annulus geometry that run through the entire solid-state history of Venus. We vary the partitioning of intrusive and extrusive volcanism from purely extrusive to dominantly intrusive and predict the present-day distributions of crustal thickness and surface age in the stagnant lid regime. With more intrusive magmatism, average crustal thickness is reduced by 20-25%, but mean crustal thickness still exceeds other independent estimates. The surface is on average much older, which is more consistent with mean age estimates from crater counting. However, lateral age variations also become stronger with dominantly intrusive volcanism, which indicates that volcanism keeps going on, but is more restricted spatially. Governing parameters like mantle reference viscosity and relative enrichment of heat-producing elements into the crust change the absolute values of mean crustal thickness and surface age, but do not improve surface age uniformity. This is somewhat at odds with Venus’ seemingly uniform surface age, so suitable conditions for this possibility are further evaluated in models featuring episodic overturn events.</p>

Reconciling thermal regimes and tectonics of the early Earth

Geology ◽  
2019 ◽  
Vol 47 (10) ◽  
pp. 923-927 ◽  
Author(s):  
F.A. Capitanio ◽  
O. Nebel ◽  
P.A. Cawood ◽  
R.F. Weinberg ◽  
P. Chowdhury
Keyword(s):  
High Pressure ◽  
Mantle Convection ◽  
Plate Tectonics ◽  
Early Earth ◽  
Plate Tectonic ◽  
Metamorphic Belt ◽  
Thermal Regimes ◽  
Tectonic Environments

Abstract Thermomechanical models of mantle convection and melting in an inferred hotter Archean Earth show the emergence of pressure-temperature (P-T) regimes that resemble present-day plate tectonic environments yet developed within a non–plate tectonics regime. The models’ P-T gradients are compatible with those inferred from evolving tonalite-trondhjemite-granodiorite series rocks and the paired metamorphic belt record, supporting the feasibility of divergent and convergent tectonics within a mobilized, yet laterally continuous, lithospheric lid. “Hot” P-T gradients of 10–20 °C km–1 form along asymmetric lithospheric drips, then migrate to areas of deep lithospheric downwelling within ∼300–500 m.y., where they are overprinted by high-pressure warm and, later, cold geothermal signatures, up to ∼8 °C km–1. Comparisons with the crustal production and reworking record suggest that this regime emerged in the Hadean.

Forced subduction initiation at passive continental margins: Numerical modeling

2020 ◽  
Author(s):  
Xinyi Zhong ◽  
Zhong-Hai Li
Keyword(s):  
Subduction Zones ◽  
Plate Tectonics ◽  
Numerical Models ◽  
Oceanic Lithosphere ◽  
Ocean Basin ◽  
Passive Margin ◽  
Complex Case ◽  
Subduction Initiation ◽  
Boundary Force ◽  
Time Required

<p>Subduction initiation (SI) induced by the tectonic boundary force may play a significant role in the Wilson cycle. In the previous analog and numerical models, the constant convergent velocity is generally applied, which may lead to large boundary forces for SI. In this study, we begin with testing the simple case of SI at passive margin with constant convergent force. The results indicate that the boundary force required to trigger the SI at passive margin with a thin and young oceanic lithosphere is much lower than that with a thick and old one. It is consistent with the multiple Cenozoic subduction zones in the Southwest Pacific, which are young ocean basin within 40 Ma and compressed by the India-Australia plate. Furthermore, we extended our model to explore a more complex case, forced SI during the collision-induced subduction transference, which is critical for Tethyan evolution. Both collision and SI processes are integrated in the numerical models. The results indicate that the forced convergence, rather than pure free subduction, is required to trigger and sustain the SI in the neighboring passive margin after collision of terrane. In addition, a weak passive margin can significantly promote the occurrence of subduction initiation, by decreasing required boundary force within reasonable range of plate tectonics. However, the lengths of subducted oceanic slab and accreting terrane play secondary roles in the occurrence of SI after collision. Under the favorable conditions of collision-induced subduction transference, the time required for subduction initiation after collision is generally within 10 Myrs, which is consistent with the general geological records of Neo-Tethys. In contrast, both Atlantic passive margin and Indian passive margin are old and stable with absence of subduction initiation in the present, which remains an open question.</p>

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