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2 edition of Rapid vertical tectonics in ductile continental crust. found in the catalog.

Rapid vertical tectonics in ductile continental crust.

Jillian Pearse

Rapid vertical tectonics in ductile continental crust.

by Jillian Pearse

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  • 40 Currently reading

Published .
Written in English

    Subjects:
  • Physics Theses.

  • About the Edition

    Research over the past two decades has shown that in regions of moderately high heat flow, the lower continental crust is ductile enough to flow on geological timescales. Vertical motions taking place within continental interiors produce localized features such as intracratonic basins and domes, and the results of this thesis indicate that ductile crustal flow can contribute significantly to the formation of these otherwise enigmatic features. A major goal of this thesis has been to analyze, quantitatively, the behaviour of loaded continental crust where a ductile layer is present.If the crust is sufficiently weakened, the long-term result is detachment of the load followed by rebound and inversion of the basin to form a dome. To model this phenomenon I use a full thermal and viscoelastic finite-element model, and find that such load detachment can occur for geologically reasonable load densities in high heat flow regions. Strikingly, the total upward displacement of material from depth during rebound can be as much as 10 km, enough to exhume the basin completely and expose basement rocks to some depth. Exhumation is rapid, lasting only about 5 to 10 million years. This raises the interesting question of what field evidence might support such a history for a dome: the results of my simulations are consistent with many of the features of metamorphic core complexes in the southern Basin and Range province, although an additional mechanism may be required to explain the exposure of rocks that originated at mid-crustal depths.Specifically, I examine the long-term effects of sublithospheric heating events on crust with embedded density loads. Density anomalies within the crust can be initially supported by elastic stresses but sag appreciably if the elastic crust is thinned modestly. Beginning with a semi-analytic approach, I estimate the additional subsidence that would result from thermal reactivation, and introduce the previously unmodelled phenomenon of thermal annealing of stresses at the base of the elastic crust. In basins caused by intracrustal density loads, reactivated subsidence can be significant (of the order of 1 km, enough to account for about one quarter of the total Michigan basin subsidence).

    Edition Notes

    ContributionsRichard Bailey (Supervisor).
    The Physical Object
    Pagination215 leaves.
    Number of Pages215
    ID Numbers
    Open LibraryOL21303016M
    ISBN 100494078103

    Plate Tectonics & Crustal Evolution, Second Edition covers the role of plate tectonics in the geologic past in light of existing geologic evidence, and examples of plate reconstructions. The book discusses the important physical and chemical properties of the crust and upper mantle in terms of models for crustal origin and evolution. Continental crust. In contrast to oceanic crust, continental crust has constantly formed throughout much of the Earth's history, with the oldest rocks from Greenland dating back to billion years, and the oldest known mineral, a zircon from the Pilbara region of Western Australia dating at billion years.

    ranges could be explained by vertical crustal movement, as explained by geosynclinal theory. It was observed as Tectonic plates can include continental crust or oceanic crust, and a single plate typically carries both. For example, the African Plate includes the continent and parts of the floor of the Atlantic and Indian the ductile. The vertical and horizontal distribution of present-day continental deformation is examined to see how tectonic movements may be related to large wavelength perturbations to the temperature and pressure experienced by rocks in the crust. Earthquakes are generally restricted to the upper part of the continental crust. The.

    Rate at which the stress is applied is in general slow (tectonic rates). When the rate is applied slowly, the minerals have time to re-crystallize and re-arrange bonds and behave in a ductile manner. Rapid application of stress does not allow for re . Combines a historical approach with process science to provide a careful balance between geological and geophysical material in both continental and oceanic regimes.\/span>\"@ en\/a> ; \u00A0\u00A0\u00A0\n schema:description\/a> \" 1 Historical perspective: Continental drift -- Sea floor spreading and the birth of plate tectonics --


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Rapid vertical tectonics in ductile continental crust by Jillian Pearse Download PDF EPUB FB2

Rapid vertical tectonics in ductile continental crust - NASA/ADS Research over the past two decades has shown that in regions of moderately high heat flow, the lower continental crust is ductile enough to flow on geological by: 2. @article{osti_, title = {The continental crust: Its composition and evolution}, author = {Taylor, S R and McLennan, S M}, abstractNote = {This book describes the composition of the present upper crust, and deals with possible compositions for the total crust and the inferred composition of the lower Rapid vertical tectonics in ductile continental crust.

book. The question of the uniformity of crustal composition. The localization of strain in the continental crust during compressional tectonics is examined using the active structures at the Nanga Parbat massif, an exhumed tract of Indian continental crust Cited by: Diapirism produces a characteristic dome-and-basin structure that may be characteristic of vertical tectonics in hot, ductile Archean continental crust.

The higher temperature results from the decay of radioactive elements, which were more abundant in Archean continental crust. Geodynamic evolution of the reference model (EXP 1) after (a) Myrs, (b) Myrs, and (c) Myrs using viscoplastic (Newtonian creep and no cohesion) continental.

During the intra-continental shear stage of margin development, rapid vertical move- ment of the crust may occur resulting in small, tectonically-active basins containing thick sedimentary sequences.

At deeper levels in the continental crust, more plastic deforma- tion may lead to a zone of strongly sheared rocks that widens downwards. A decade ago, Glazner pointed out that density anomalies such as mafic plutons in reheated continental crust will drive vertical tectonics by ductile remobilization and subsidence as a result of buoyancy forces, and that this can be a relatively rapid process.

they can facilitate rapid vertical movement of their roots, which often include ductile shear zones pene-trating most, or all of the lithosphere (e.g.

Hanmer et al. ; Leloup et al. ; Vauchez & Tommasi ; Watkinson et al. The Palu-Koro fault of central Sulawesi is an active, north–south-trending high strain rate sinis. Metamorphic core complexes are domal uplifts of metamorphic and plutonic rocks bounded by shear zones that separate them from unmetamorphosed cover rocks1.

Interpretations of how these features. Tectonics presents original research articles that describe and explain the evolution, structure, and deformation of Earth’s lithosphere including across the range of geologic time.

Formation often requires oblique or rotational kinematics as well as the presence of inherited structures in the continental crust; Toward the base of the. Moreover, when thick continental crust is entrained into a subduction zone, the slab can also detach, and this is possibly associated with a rapid isostatic uplift of the overriding plate.

This process is apparent in the correlation between the tectonic evolution of various margins with tomographic images of slabs (e.g., ref.

Gravitational collapse of the continental crust: Definition, regimes and modes Article (PDF Available) in Tectonophysics (3) December. A diapir is a teardrop-shaped body of solid but ductile, low-density rock that ascends through denser, more rigid rock.

Examples include icy, mud, or salt (gypsum) diapirs in sedimentary sequences, or dome-like intrusions of granitic gneiss in Archean cratons. Diapirism refers to an upward migration of low-density diapirs, commonly accompanied by downward migration of. This raises a major problem in continental tectonics, because field evidence shows strain localization and the development of major detachment faults at typical depths of the brittle–ductile.

Tectonics explores structures and processes from regional to global, differentiating itself from the material covered in most structural geology textbooks.

Moores and Twiss emphasize basic principles and methodologies of tectonics, embracing the time-honored perspective of using present processes to understand the past.

Frisch and Meschede and Blakey answer all these questions and more through the presentation and explanation of the geodynamic processes upon which the theory of continental drift is based and which have led to the concept of plate tectonics.

The earth’s crust was typically pictured as dynamic and capable of rapid vertical and horizontal motions on local, regional, and global scales. However, especially with the influential works of Hutton 5, 6 and then Lyell, 7 Noah’s Flood began to play an increasingly less important role in historical geology during the nineteenth century.

Plate tectonics is the scientific theory explaining the movement of the earth’s crust. It is widely accepted by scientists today.

Recall that both continental landmasses and the ocean floor are part of the earth’s crust, and that the crust is broken into individual pieces called tectonic. subjected to tectonic forces, while the more ductile zones flow under stress. These rheological differences within the crust and upper mantle allow variation in the magnitude of deviatoric stress, and such variation has a profound effect on tabular intrusions.

A vertical dike intruding into extending crust increases the horizontal least principal. INTRODUCTION. Geodynamic models commonly describe the relation between buoyancy-driven mantle convection and plate tectonics with two components of traction applied to the base of the lithosphere—vertical tractions giving rise to dynamic topography (1, 2), and horizontal basal tractions driving plate motion and tectonic deformation ().Although lithospheric stress field.

The others are underlain by either thinned continental crust, or fragments of continental crust, arcs, and oceanic rocks swept together as a collage and forming a basement for late Paleozoic, Mesozoic, and Cenozoic arcs and sedimentary sequences that make up current tectonic .Structure and Tectonics of the Indian Continental Crust and Its Adjoining Region: Deep Seismic Studies, Second Edition,collates essential data from seismic studies of Earth's crust across India, offering an essential understanding of the tectonic development of the Indian c studies have been carried out in various parts of India sincerecording crust.

Catastrophic plate tectonics is a theory that proposes rapid movement of the Earth's plates during the flood of Noah by runaway subduction. It was originally derived by Dr. John Baumgardner, and supported by sophisticated computer is one of several alternatives to Plate Tectonics theory, which include Expanding earth theory, Hydroplate .