William R. Dickinson (1931–2015): Hero of plate tectonics, sedimentary basins, and provenance

Author(s):  
Raymond V. Ingersoll ◽  
Timothy F. Lawton ◽  
Richard A. Schweickert ◽  
Stephan A. Graham
2020 ◽  
Author(s):  
Mark Hoggard ◽  
Karol Czarnota ◽  
Fred Richards ◽  
David Huston ◽  
Lynton Jaques ◽  
...  

<p>Sustainable development and transition to a clean-energy economy is placing ever-increasing demand on global supplies of base metals (copper, lead, zinc and nickel). Consumption over the next ~25 years is set to exceed the total produced in human history to date, and it is a growing concern that the rate of exploitation of existing reserves is outstripping discovery of new deposits. Therefore, improvements in the effectiveness of exploration are required to reverse this worrying trend and maintain growth in global living standards.</p><p>Approximately 70% of known lead, 55% of zinc and 20% of copper has been deposited between 2 Ga and recent by low temperature hydrothermal circulation in shallow sedimentary basins. These basins are formed by extension and rifting, which are key manifestations of the plate-mode of tectonics. Despite 150 years of research, the relationship between deposit locations and local geological structure is enigmatic and there remains no accurate technique for predicting their distribution at continental scales.</p><p>Here, we show that modern surface wave tomography and recent parameterisations for anelasticity at seismic frequencies can be used to map lithospheric structure, and that sediment-hosted base metal deposits occur exclusively along the edges of thick lithosphere. Approximately 90% of the world's sediment-hosted copper, lead and zinc resources lie within 200 km of these boundaries, including all giant deposits (>10 megatonnes of metal). Incorporation of higher resolution regional seismic studies into global lithospheric thickness models further enhances the robustness of this relationship. </p><p>This observation implies that lithospheric architecture imparted by the plate-mode of tectonics is stable over billion-year timescales, and that there is a genetic link between lithospheric scale  processes and near-surface hydrothermal mineral systems. Our new maps provide an unprecedented global means to identify fertile regions for targeted mineral exploration, and provide a clear economic justification for funding targeted seismic arrays, theoretical advances in imaging techniques, and geodynamic studies that improve our understanding of deep-time plate tectonics.</p>


2021 ◽  
Vol 124 (1) ◽  
pp. 111-140
Author(s):  
L.J. Robb ◽  
F.M. Meyer ◽  
C.J. Hawkesworth ◽  
N.J. Gardiner

ABSTRACT The Barberton region of South Africa is characterized by a broad variety of granite types that range in age from ca. 3.5 Ga to 2.7 Ga and reflect the processes involved in the formation of Archaean continental crust on the Kaapvaal Craton. These granites are subdivided into three groups, as follows: A tonalite-trondhjemite-granodiorite (TTG) suite diapirically emplaced at 3 450 Ma and 3 250 Ma into pre-existing metamorphosed greenstone belt material. TTG melts were derived from melting amphibolite in the lower crust, with individual plutons being emplaced at various crustal levels. The dome-and-keel geometry that characterizes the TTG-greenstone dominated crust at this time is inconsistent with a plate tectonic domain and reworking was likely controlled by gravity inversion or ‘sagduction’; Regionally extensive potassic batholiths (the GMS suite) were emplaced at 3 110 Ma during a period of crustal thickening and melting of a TTG-dominated lower crust. Subsequent to emplacement of the voluminous GMS granites, the thickened continental crust had stabilized sufficiently for large sedimentary basins to form; Late granite plutons were emplaced along two distinct linear and sub-parallel arrays close to what might have been the edge of a Kaapvaal continent at 2 800 to 2 700 Ma. They are subdivided into high-Ca and low-Ca granites that resemble the I- and S-type granites of younger orogenic episodes. The high-Ca granites are consistent with derivation from older granitoids in the lower crust, whereas the low-Ca granites may have been derived by melting metasedimentary precursors in the lower-mid crust. Granites with similar characteristics are associated with a subduction zone in younger terranes, although the recognition of such a feature at Barberton remains unclear. The petrogenesis of granites in the Barberton region between 3.5 Ga and 2.7 Ga provides a record of the processes of Archaean crustal evolution and contributes to discussions related to the onset of plate tectonics.


1977 ◽  
Vol 14 (10) ◽  
pp. 2414-2421 ◽  
Author(s):  
G. H. Eisbacher

Paleogeographic maps for the clastic successions of Early Jurassic, Late Jurassic – Early Cretaceous, and Late Cretaceous – early Tertiary time depict important geologic features that have to be considered in modelling of the Mesozoic sedimentary basins of the Canadian Cordillera. The relative positions of clastic basins, reverse fault zones, and volcanic complexes suggest that the crustal elements underlying the western Cordillera were foreshortened and thickened increasingly from early Mesozoic to early Tertiary. Throughout the late Mesozoic the Canadian Cordillera displayed subdued topography. Uplift was dramatic and possibly of Andean proportions during the latest Eocene and Oligocene. Reconstruction of paleogeography along major right-lateral faults suggests the possibility that old basement trends of the cratonic foreland may have had a profound influence on structures west of the Rocky Mountains. In terms of plate tectonics the Mesozoic basins of the Canadian Cordillera are marginal or possibly intra-arc basins, and cannot be compared easily with the presumed forearc basin containing the late Mesozoic Great Valley Sequence of California.


2021 ◽  
pp. SP524-2021-94
Author(s):  
Attila Bálazs ◽  
Taras Gerya ◽  
Dave May ◽  
Gábor Tari

AbstractTransform and passive margins developed during the continental rifting and opening of oceanic basins are fundamental elements of plate tectonics. It has been suggested that inherited structures, plate divergence velocities and surface processes exert a first order control on the topographic and bathymetric evolution and thermal history of these margins and related sedimentary basins. Their complex spatial-temporal dynamics have remained controversial. Here, we conducted 3D magmatic-thermo-mechanical numerical experiments coupled with surface processes modelling to simulate the dynamics of continental rifting, continental transform fault zone formation and persistent oceanic transform faulting and zero-offset oceanic fracture zones development. Numerical modelling results allow to explain the first order observations from passive and transform margins, such as diachronous rifting, heat flow rise and cooling in individual depocenters and contrasting basin tectonics of extensional and transtensional origin. In addition, the models reproduce the rise of both marginal ridges and transform marginal plateaus and their interaction with erosion and sedimentation. Comparison of model results with observations from natural examples yield new insights into the tectono-sedimentary and thermal evolution of several key passive and transform continental margins worldwide.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5756555


2020 ◽  
Author(s):  
Florian Krob ◽  
Ulrich A. Glasmacher ◽  
Hans-Peter Bunge ◽  
Anke M. Friedrich ◽  
Peter C. Hackspacher

<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>


1993 ◽  
Vol 30 (2) ◽  
pp. 261-277 ◽  
Author(s):  
Jacob Verhoef ◽  
Walter R. Roest

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.


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