scholarly journals Exploring the theory of plate tectonics: the role of mantle lithosphere structure

2018 ◽  
Vol 470 (1) ◽  
pp. 137-155 ◽  
Author(s):  
Philip J. Heron ◽  
Russell N. Pysklywec ◽  
Randell Stephenson

AbstractThis review of the role of the mantle lithosphere in plate tectonic processes collates a wide range of recent studies from seismology and numerical modelling. A continually growing catalogue of deep geophysical imaging has illuminated the mantle lithosphere and generated new interpretations of how the lithosphere evolves. We review current ideas about the role of continental mantle lithosphere in plate tectonic processes. Evidence seems to be growing that scarring in the continental mantle lithosphere is ubiquitous, which implies a reassessment of the widely held view that it is the inheritance of crustal structure only (rather than the lithosphere as a whole) that is most important in the conventional theory of plate tectonics (e.g. the Wilson cycle). Recent studies have interpreted mantle lithosphere heterogeneities to be pre-existing structures and, as such, linked to the Wilson cycle and inheritance. We consider the current fundamental questions in the role of the mantle lithosphere in causing tectonic deformation, reviewing recent results and highlighting the potential of the deep lithosphere in infiltrating every aspect of plate tectonics processes.

2014 ◽  
Vol 51 (3) ◽  
pp. xvii-xxxi
Author(s):  
Gordon F. West ◽  
Ron M. Farquhar ◽  
George D. Garland ◽  
Henry C. Halls ◽  
Lawrence W. Morley ◽  
...  

Fifty years ago, the world’s Earth Scientists experienced the so-called “Revolution in the Earth Sciences”. In the decade from 1960 to 1970, a massive convergence took place from many diverse and contradictory theories about the tectonic processes operating on Earth (then loosely called “mountain building”) to a single widely accepted paradigm now called Plate Tectonics. A major player in leading the international “Revolution” was Canadian geophysicist J. Tuzo Wilson. This tribute reviews how he helped define and promote the Plate Tectonic paradigm, and also, from 1946 to 1967, how he led a rapid expansion of the role of geophysics in Canadian and international earth science. Wilson was a controversial figure before and during the “Revolution”, but his influence was large. It was not coincidental that earth science research in Canada grew by 1964 to the point where the National Research Council of Canada could add the Canadian Journal of Earth Sciences to its group of Canadian research journals.


2014 ◽  
Vol 51 (3) ◽  
pp. 187-196
Author(s):  
David J. Dunlop

John Tuzo Wilson coined the term “plate” in plate tectonics. He is famous for inventing transform boundaries, hot spot tracks, and the Wilson cycle of ocean birth, growth, and decline. Less well remembered is his work in the 1950s on tectonic and radiometric age provinces of the Canadian Shield, as part of which he fathered U/Pb geochronology in Canada. This work gave strong support to the notion of continental growth through accretion of successively younger terranes onto an ancient cratonic core. The present paper reviews how paleomagnetism can trace the motions of continents to test Wilson’s ideas. Continental accretion often involves deep burial of one of the colliding elements through subduction or crustal underplating; such was the case with the Grenville orogen and its subprovinces in their Proterozoic accretion onto the Laurentian craton. The resulting heating and metamorphism erases most pre-collisional magnetic information but adds something new: the possibility of following the post-metamorphic uplift and cooling history, in time and space. The time element is provided by a new form of isotopic geochronology, thermochronometry, which provides dates for specific minerals together with the temperatures at which they became closed to isotopic migration. U/Pb dating of sphene is one method used; another is the 40Ar/39Ar variant of K/Ar dating applied to hornblende, micas, and feldspars, which have a wide range of Ar closure temperatures. The two specific Grenville studies described deal with parallel uplift histories determined by 40Ar/39Ar dating and by magnetics for the accreted terranes of the Central Metasedimentary Belt in Ontario and with the paleomagnetic detection of the post-1240 Ma closing of a small ocean between the Elsevir terrane and Laurentia during the Grenvillian orogeny.


Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 453
Author(s):  
Gina L. Barnes

This article proposes a new subdiscipline, Tectonic Archaeology, based on the efforts of Japanese archaeologists to deal with the effects of earthquakes, volcanic tephra cover, and tsunami on archaeological sites. Tectonic Archaeology is conceived as an umbrella term for those efforts and as a foundation for Geoarchaeology in general. Comparisons distinguish between Geoarchaeology and Tectonic Archaeology, and a survey of major archaeological journals and textbooks reveals how the concept of ‘tectonics’ and specifically the processes of Plate Tectonics have been treated. Al-though the term ‘tectonics’ occurred fairly frequently, particularly as affecting coastlines and sea levels, it was not thoroughly defined and discussed. Volcanic activity was most mentioned in journals due to its provision of resources and modification of the landscape, while the 2011 earthquake and tsunami in Japan seems to have stimulated more studies in Archaeoseismology. The textbooks were found to have scattered references to Plate Tectonic processes but no clear approach tying these together. The major exception is the Encyclopedia of Archaeology which addresses volcanoes, Archaeoseismology, and tsunami—soon to be linked together vis à vis Earth processes. Tectonic Archaeology attempts first to explain the processes of Plate Tectonics to underwrite investigation of their effects; it is applicable worldwide, in continental and coastal contexts.


Geology ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 103-107 ◽  
Author(s):  
An Yin ◽  
Günther Brandl ◽  
Alfred Kröner

Abstract We addressed when plate-tectonic processes first started on Earth by examining the ca. 2.0 Ga Limpopo orogenic belt in southern Africa. We show through palinspastic reconstruction that the Limpopo orogen originated from >600 km of west-directed thrusting, and the thrust sheet was subsequently folded by north-south compression. The common 2.7–2.6 Ga felsic plutons in the Limpopo thrust sheet and the absence of an arc immediately predating the 2.0 Ga Limpopo thrusting require the Limpopo belt to be an intracontinental structure. The similar duration (∼40 m.y.), slip magnitude (>600 km), slip rate (>15 mm/yr), tectonic setting (intracontinental), and widespread anatexis to those of the Himalayan orogen lead us to propose the Limpopo belt to have developed by continent-continent collision. Specifically, the combined Zimbabwe-Kaapvaal craton (ZKC, named in this study) in the west (present coordinates) was subducting eastward below an outboard craton (OC), which carried an arc equivalent to the Gangdese batholith in southern Tibet prior to the India-Asia collision. The ZKC-OC collision at ca. 2.0 Ga triggered a westward jump in the plate convergence boundary, from the initial suture zone to the Limpopo thrust within the ZKC. Subsequent thrusting accommodated >600 km of plate convergence, possibly driven by ridge push from the west side of the ZKC. As intracontinental plate convergence is a key modern plate-tectonic process, the development of the Limpopo belt implies that the operation of plate tectonics, at least at a local scale, was ongoing by ca. 2.0 Ga on Earth.


Author(s):  
A. Lenardic

Plate tectonics is a particular mode of tectonic activity that characterizes the present-day Earth. It is directly linked to not only tectonic deformation but also magmatic/volcanic activity and all aspects of the rock cycle. Other terrestrial planets in our Solar System do not operate in a plate tectonic mode but do have volcanic constructs and signs of tectonic deformation. This indicates the existence of tectonic modes different from plate tectonics. This article discusses the defining features of plate tectonics and reviews the range of tectonic modes that have been proposed for terrestrial planets to date. A categorization of tectonic modes relates to the issue of when plate tectonics initiated on Earth as it provides insights into possible pre-plate tectonic behaviour. The final focus of this contribution relates to transitions between tectonic modes. Different transition scenarios are discussed. One follows classic ideas of regime transitions in which boundaries between tectonic modes are determined by the physical and chemical properties of a planet. The other considers the potential that variations in temporal evolution can introduce contingencies that have a significant effect on tectonic transitions. The latter scenario allows for the existence of multiple stable tectonic modes under the same physical/chemical conditions. The different transition potentials imply different interpretations regarding the type of variable that the tectonic mode of a planet represents. Under the classic regime transition view, the tectonic mode of a planet is a state variable (akin to temperature). Under the multiple stable modes view, the tectonic mode of a planet is a process variable. That is, something that flows through the system (akin to heat). The different implications that follow are discussed as they relate to the questions of when did plate tectonics initiate on Earth and why does Earth have plate tectonics. This article is part of a discussion meeting issue ‘Earth dynamics and the development of plate tectonics’.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xin Zhou ◽  
Ikuko Wada

AbstractDespite the critical role of subduction in plate tectonics, the dynamics of its initiation remains unclear. High-temperature low-pressure metamorphic soles are vestiges of subduction initiation, providing records of the pressure and temperature conditions along the subducting slab surface during subduction initiation that can possibly differentiate the two end-member subduction initiation modes: spontaneous and induced. Here, using numerical models, we show that the slab surface temperature reaches 800–900 °C at ~1 GPa over a wide range of parameter values for spontaneous subduction initiation whereas for induced subduction initiation, such conditions can be reached only if the age of the overriding plate is <5 Ma. These modeling results indicate that spontaneous subduction initiation would be more favorable for creating high-temperature conditions. However, the synthesis of our modeling results and geological observations indicate that the majority of the metamorphic soles likely formed during induced subduction initiation that involved a young overriding plate.


2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.


2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.


Author(s):  
C. Claire Thomson

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.


2020 ◽  
pp. 102-109
Author(s):  
Svetlana Alekseevna Raschetina ◽  

Relevance and problem statement. Modern unstable society is characterized by narrowing the boundaries of controlled socialization and expanding the boundaries of spontaneous socialization of a teenager based on his immersion in the question arises about the importance of the family in the process of socialization of a teenager in the conditions of expanding the space of socialization. There is a need to study the role of the family in this process, to search, develop and test research methods that allow us to reveal the phenomenon of socialization from the side of its value characteristics. The purpose and methodology of the study: to identify the possibilities of a systematic and anthropological methodology for studying the role of the family in the process of socialization of adolescents in modern conditions, testing research methods: photo research on the topic “Ego – I” (author of the German sociologist H. Abels), profile update reflexive processes (by S. A. Raschetina). Materials and results of the study. The study showed that for all the problems that exist in the family of the perestroika era and in the modern family, it acts for a teenager as a value and the first (main) support in the processes of socialization. The positions well known in psychology about the importance of interpersonal relations in adolescence for the formation of attitudes towards oneself as the basis of socialization are confirmed. Today, the frontiers of making friends have expanded enormously on the basis of Internet communication. The types of activities of interest to a teenager (traditional and new ones related to digitalization) are the third pillar of socialization. Conclusion. The “Ego – I” method of photo research has a wide range of possibilities for quantitative and qualitative analysis of the socialization process to identify the value Pillars of this process.


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