Reading the stripes: offshore discoveries in plate tectonics with examples from eastern Canada

1993 ◽  
Vol 30 (2) ◽  
pp. 261-277 ◽  
Author(s):  
Jacob Verhoef ◽  
Walter R. Roest
Keyword(s):  
Plate Tectonics ◽  
Sedimentary Basins ◽  
Geological Survey ◽  
Continental Margins ◽  
Eastern Canada ◽  
Data Set ◽  
Grand Banks ◽  
The Earth ◽  
Wide Acceptance

The emergence and wide acceptance of plate tectonics has had a profound influence on the way we look at the Earth. Starting as a theory to explain similarities in coast lines across the Atlantic, plate tectonics has become a unifying theory in the earth sciences. In this paper, we describe the role of staff of the Geological Survey of Canada in the developing and refining of this theory. At the same time, we illustrate the effect plate tectonics has had on our understanding of the evolution of offshore eastern Canada. Of critical importance in this development was the unique data set collected by systematic surveying of this region, largely by the Geological Survey of Canada, making the Grand Banks of Newfoundland one of the best-studied offshore areas in the world. Plate tectonic theory not only offers a framework for the evolution of ocean basins, continental margins, and their sedimentary basins, but also for the assemblage of continents.

3. Minerals and the interior of the Earth

2014 ◽  
Author(s):  
David Vaughan
Keyword(s):  
Upper Mantle ◽  
Lower Mantle ◽  
Plate Tectonics ◽  
Inner Core ◽  
Indirect Evidence ◽  
Outer Core ◽  
The Earth ◽  
Granite Formation ◽  
Temperature And Pressure

‘Minerals and the interior of the Earth’ looks at the role of minerals in plate tectonics during the processes of crystallization and melting. The size and range of minerals formed are dependent on the temperature and pressure of the magma during its movement through the crust. The evolution of the continental crust also involves granite formation and processes of metamorphism. Our understanding of the interior of the Earth is based on indirect evidence, mainly the study of earthquake waves. The Earth consists of concentric shells: a solid inner core; liquid outer core; a solid mantle divided into a lower mantle, a transition zone, and an upper mantle; and then the outer rigid lithosphere.

The Tectonic Plates are Moving!

2018 ◽  
Author(s):  
Roy Livermore
Keyword(s):  
Plate Tectonics ◽  
First Generation ◽  
Volcanic Eruptions ◽  
Short Article ◽  
Tectonic Plates ◽  
The Earth ◽  
Deep Interior ◽  
Two Generations ◽  
The 1960S

Written in a witty and informal style, this book explains modern plate tectonics in a non-technical manner, showing not only how it accounts for phenomena such as great earthquakes, tsunamis, and volcanic eruptions, but also how it controls conditions at the Earth’s surface, including global geography and climate, making it suitable for life. The book presents the advances that have been made since the establishment of plate tectonics in the 1960s, highlighting, on the fiftieth anniversary of the theory, the contributions of a small number of scientists who have never been widely recognized for their discoveries. Beginning with the publication of a short article in Nature by Vine and Matthews, the book traces the development of plate tectonics through two generations of the theory. First-generation plate tectonics covers the exciting scientific revolution of the 1960s, its heroes, and its villains. The second generation includes the rapid expansions in sonar, satellite, and seismic technologies during the 1980s and 1990s that provided a truly global view of the plates and their motions, and an appreciation of the role of their within the Earth system. Arriving at the cutting edge of the science, the latest results from studies using techniques such as seismic tomography and mineral physics to probe the deep interior are discussed and the prospects for finding plate tectonics on other planets assessed. Ultimately, the book leads to the startling conclusion that, without plate tectonics, the Earth would be as lifeless as Venus.

scholarly journals The fate of water within Earth and super-Earths and implications for plate tectonics

2017 ◽  
Vol 375 (2094) ◽  
pp. 20150394 ◽  
Author(s):  
Sonia M. Tikoo ◽  
Linda T. Elkins-Tanton
Keyword(s):  
Upper Mantle ◽  
Plate Tectonics ◽  
Extrasolar Planets ◽  
Internal Heat ◽  
Magma Ocean ◽  
Nominally Anhydrous Minerals ◽  
The Earth ◽  
Giant Impacts ◽  
Crystallographic Defects

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subduction. The following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? The giant impacts of late accretion created magma lakes and oceans, which degassed during solidification to produce a heavy atmosphere. However, some water would have remained in the mantle, trapped within crystallographic defects in nominally anhydrous minerals. In this paper, we present models demonstrating that processes associated with magma ocean solidification and overturn may segregate sufficient quantities of water within the upper mantle to induce partial melting and produce a damp asthenosphere, thereby facilitating plate tectonics and, in turn, the habitability of Earth-like extrasolar planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’.

scholarly journals Geodynamic modeling of the process of formation and evolution of lithospheric structures: experience of Schmidt institute of physics of the earth RAS

2019 ◽  
pp. 122-133
Author(s):  
V. O. Mikhailov ◽  
E. P. Timoshkina
Keyword(s):  
Large Scale ◽  
Sedimentary Basins ◽  
Geophysical Data ◽  
Small Scale ◽  
Tectonic Structures ◽  
The Earth ◽  
Basin Formation ◽  
Formation And Evolution ◽  
Geodynamic Models

Key results of numerical geodynamic modeling of the structures of the lithosphere at the Institute of Physics of the Earth of the Russian Academy of Sciences are presented. Even in the very first models, the aim of these studies was to describe the time evolution of the boundaries of the layers composing the geological structures which is required for correlating the modeling results to the geological and geophysical data. In 1983, the equation of motion for the upper boundary of the model was complemented by the allowance of sedimentation and erosion. This equation provided the basis for building the geodynamic models of the formation of various types of sedimentary basins and made it possible to mathematically analyze the problem of estimating the rates of paleotectonic movements from thickness, age, and facies composition of sedimentary layers. New data on the formation and evolution processes of large-scale tectonic structures are obtained in the model of a rheologically stratified Earth’s boundary layer, asymptotically linked to mantle convection model. In particular, the role of the small-scale convection in the formation of lithospheric structures in the tectonic settings of extension and compression has been explored. The numerical results clearly demonstrate the key role of the small-scale asthenospheric convection in sedimentary basin formation (post-rift, on passive continental margins, in foredeep basins). The constructed models served as the basis for interpretation of heterogeneous geological and geophysical data in the context of geodynamic models. The examples of statement of inverse problems are presented and the relevant bibliography is provided.

Two decades of Geological Survey of Canada petroleum resource assessments

1993 ◽  
Vol 30 (2) ◽  
pp. 321-332 ◽  
Author(s):  
P. J. Lee
Keyword(s):  
Monte Carlo ◽  
Sedimentary Basins ◽  
Process Models ◽  
Petroleum Exploration ◽  
Geological Survey ◽  
Geochemical Data ◽  
Cumulative Probability ◽  
Data Set ◽  
Petroleum Resource ◽  
Pool Sizes

The Geological Survey of Canada has conducted petroleum resource assessments of Canadian sedimentary basins to respond to a need for information concerning the extent of Canada's energy endowment. The evolution of these activities and methods, which began in the 1970's and continue to the present, is discussed in this paper. The first assessment of Canadian basins was conducted in the 1970's using a volumetric yield method, whereby the volume of sedimentary rock in a basin was multiplied by a hydrocarbon yield per unit volume factor. Later, a Monte Carlo approach was used. It required a knowledge of the exploration plays in a given basin and made use of a variety of pool parameters expressed as cumulative probability distributions. The Monte Carlo method did not account for the biased data-set problem that came from using a selective exploration process. A third assessment method was based on geochemical data and was used to estimate the amount of hydrocarbon generated and the expulsion efficiencies. The results from each of the three methods defied detailed economic analysis.Advanced statistical methods were gradually developed in the 1980's. By the end of this period, PETRIMES (the Petroleum Exploration and Resource Evaluations System) was developed. This system evaluates hydrocarbon potential by means of an exploration play definition coupled with compiled play data used to estimate undiscovered pool sizes. During this period, discovery process models were developed to account for the biased data. Estimations of individual pool sizes in the play were made and displayed graphically so that undiscovered pools could be identified in a statistically derived population of pools. Summed quantities of petroleum in undiscovered pools were used to define remaining expected play potential.The estimated undiscovered individual pool sizes inferred from assessments serve as direct input to economic analyses that examine which pools are viable prospects under specific economic conditions. This knowledge is useful to governments formulating energy policies and to petroleum companies setting exploration priorities.

Application of stratigraphic frameworks and thermochronological data on the Mesozoic SW Gondwana intraplate environment to retrieve the Paraná-Etendeka plume movement.

2020 ◽  
Author(s):  
Florian Krob ◽  
Ulrich A. Glasmacher ◽  
Hans-Peter Bunge ◽  
Anke M. Friedrich ◽  
Peter C. Hackspacher
Keyword(s):  
Mantle Plume ◽  
Plate Tectonics ◽  
Convective Motion ◽  
Sedimentary Basins ◽  
Plate Motion ◽  
Data Sets ◽  
The Earth ◽  
Stratigraphic Framework ◽  
Sw Gondwana ◽  
Event Based

<p>Since plate tectonics has been linked to material flow in the Earth’s mantle, it is commonly accepted that convective motion in the sublithospheric mantle results in vertical deflections and horizontal plate motion on the Earth’s surface. Those mantle flow-driven vertical deflections are recognized through significant signals and traces in the sedimentary records (unconformities and missing sections). Recently, Friedrich et al. (2018) introduced an event-based plume stratigraphic framework that uses such signals in the stratigraphic record to detect the geological evolution near, and on the Earth’s surface in areas of interregional scale caused by mantle plume movement. Information about these dynamic processes is stored in geological archives, such as (1) stratigraphic records of sedimentary basins and (2) thermochronological data sets of igneous, metamorphic, and sedimentary rocks.</p><p>For the first time, this research combines these two geological archives and applies them to the Mesozoic SW Gondwana intraplate environment to retrieve the Paraná-Etendeka plume movement prior to the Paraná-Etendeka LIP. We compiled 18 stratigraphic records of the major continental and marine sedimentary basins and over 35 thermochronological data sets including >1300 apatite fission-track ages surrounding the Paraná-Etendeka Large Igneous Province to test the event-based plume stratigraphic framework and its plume stratigraphic mapping to retrieve the timing and spatial distribution of the Paraná-Etendeka plume.</p><p>The plume stratigraphic mapping, using the stratigraphic records is suitable to demark a possible plume center, plume margins and distal regions (Friedrich et al., 2018). Thermochronological data reveal centers of a significant thermal Paraná-Etendeka plume influence. Both archives show significant signals and traces of mantle plume movement well in advance of the flood basalt eruptions. Our LTT data combined with stratigraphic records are modeled successfully with respect to a viable mantle plume driven thermal evolution and therefore, we suggest that thermochronological data, in combination with stratigraphy records have the potential to retrieve the Paraná-Etendeka plume movement.</p>

Plate Tectonics and Macrogeomorphology

2021 ◽  
pp. M58-2021-12
Author(s):  
Michael A. Summerfield
Keyword(s):  
Plate Tectonics ◽  
Earth Science ◽  
Significant Advance ◽  
Continental Margins ◽  
Geological Time ◽  
Landscape Development ◽  
The Earth ◽  
The Status ◽  
Technical Innovations ◽  
Global Tectonics

AbstractThe plate tectonics revolution was the most significant advance in our understanding of the Earth in the 20th century, but initially it had little impact on the discipline of geomorphology. Topography and landscape development were not considered to be important phenomena that deserved attention from the broader earth-science community in the context of the new model of global tectonics. This situation began to change from the 1980s as various technical innovations enabled landscape evolution to be modelled numerically at the regional to sub-continental scales relevant to plate tectonics, and rates of denudation to be quantified over geological time scales. These developments prompted interest amongst earth scientists from fields such as geophysics, geochemistry and geochronology in understanding the evolution of topography, the role of denudation in influencing patterns of crustal deformation, and the interactions between tectonics and surface processes. This trend was well established by the end of the century, and has become even more significant up to the present. In this chapter I review these developments and illustrate how plate tectonics has been related to landscape development, especially in the context of collisional orogens and passive continental margins. I also demonstrate how technical innovations have been pivotal to the expanding interest in macroscale landscape development in the era of plate tectonics, and to the significant enhancement of the status of the discipline of geomorphology in the earth sciences over recent decades.

The theory of undercurrent from the Austrian alpine geologist Otto Ampferer (1875–1947): first conceptual ideas on the way to plate tectonics

2019 ◽  
Vol 56 (11) ◽  
pp. 1095-1100
Author(s):  
Wolf-Christian Dullo ◽  
Fritz A. Pfaffl
Keyword(s):  
Upper Mantle ◽  
Plate Tectonics ◽  
Movement Pattern ◽  
Geological Survey ◽  
High Mountains ◽  
Atlantic Region ◽  
Deep Crust ◽  
The Earth ◽  
Long Time ◽  
History Of

In his paper “Über das Bewegungsbild von Faltengebirgen” [On the movement pattern of folded mountains], published in the almanac of the Austrian Geological Survey in Vienna, Otto Ampferer from Innsbruck (Austria) presented a series of geotectonic considerations and interpretations, which today are summarized under the term “theory of undercurrent”. The interpretation of these processes occurring in the deep crust of the Earth and in the upper mantle was mainly kinematic. For a long time, the tectonic passivity of the magma being anorogenic was dogma until Ampferer’s undercurrent theory changed this in 1906, according to which folds and thrusts on the Earth’s surface portray motions of the deeper magmatic substratum. In these undercurrents, Ampferer recognized the crucial forces that lead to the formation of ocean basins and high mountains on the edges of the drifting continents. In his paper on the history of the formation of the Atlantic region, he presented already, in 1941, a process anticipating what is now known as seafloor spreading.

scholarly journals Global water cycle and the coevolution of the Earth’s interior and surface environment

2017 ◽  
Vol 375 (2094) ◽  
pp. 20150393 ◽  
Author(s):  
Jun Korenaga ◽  
Noah J. Planavsky ◽  
David A. D. Evans
Keyword(s):  
Plate Tectonics ◽  
Water Cycle ◽  
Critical Role ◽  
Global Water Cycle ◽  
Water Influx ◽  
The Earth ◽  
Almost All ◽  
Global Water

The bulk Earth composition contains probably less than 0.3% of water, but this trace amount of water can affect the long-term evolution of the Earth in a number of different ways. The foremost issue is the occurrence of plate tectonics, which governs almost all aspects of the Earth system, and the presence of water could either promote or hinder the operation of plate tectonics, depending on where water resides. The global water cycle, which circulates surface water into the deep mantle and back to the surface again, could thus have played a critical role in the Earth’s history. In this contribution, we first review the present-day water cycle and discuss its uncertainty as well as its secular variation. If the continental freeboard has been roughly constant since the Early Proterozoic, model results suggest long-term net water influx from the surface to the mantle, which is estimated to be 3−4.5×10 14  g yr −1 on the billion years time scale. We survey geological and geochemical observations relevant to the emergence of continents above the sea level as well as the nature of Precambrian plate tectonics. The global water cycle is suggested to have been dominated by regassing, and its implications for geochemical cycles and atmospheric evolution are also discussed. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’.

Sign in / Sign up

Export Citation Format

Share Document