Structural analysis of the central and southwestern Sudbury Structure, Southern Province, Canadian Shield

1991 ◽  
Vol 28 (3) ◽  
pp. 411-430 ◽  
Author(s):  
W. S. Shanks ◽  
W. M. Schwerdtner
Keyword(s):  
Shear Zone ◽  
Large Scale ◽  
Vertical Plane ◽  
Surface Shape ◽  
Order Structure ◽  
The South ◽  
First Order ◽  
Sudbury Igneous Complex ◽  
Sudbury Structure ◽  
Tangent Surface

The Sudbury Structure (SS) is an unusual crater structure which acquired its present oval surface shape during northwest-directed ductile thrusting. Lower amphibolite-facies metamorphism accompanied the thrusting which generated a major reverse shear zone. At least 50 km long, the South Range shear zone (SRSZ) transects the South Range of the Sudbury Structure and exhumes a low level of the Sudbury Igneous Complex (SIC). Assuming heterogeneous simple shear in the northwest–southeast vertical plane on northeasterly striking glide surfaces, minimal estimates of net displacement across the SRSZ exceed 8 km. This displacement magnitude and the map pattern of the SIC require the southwest closure of the SS to be steeply plunging, in accord with a hypothetical funnel shape of the SIC. The rocks of the metasedimentary core of the SS are deformed into a family of second-order buckle folds, the tangent surface of which forms an upright open flexure within the first-order structure of the Sudbury synclinorium. The original orientation and bulk rotation of contacts in the SIC are unknown, so its participation in large-scale folding remains uncertain.

scholarly journals PROSPECTS OF THE POTENTIAL FOR OIL AND GAS PRESENCE IN THE NORTH-WESTERN PART OF INNER FLYSH COVERS OF THE UKRAINIAN CARPATHIANS

2019 ◽  
Vol 2 (179) ◽  
pp. 5-27
Author(s):  
Myroslav PAVLYUK ◽  
Volodymyr SHLAPINSKY ◽  
Olesya SAVCHAK ◽  
Myroslav TERNAVSKY
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
Gas Composition ◽  
The South ◽  
First Order ◽  
North East ◽  
The North ◽  
South West ◽  
The Given ◽  
North Western

Here the Cretaceous and Paleogene flysh of the Duklya-Chornohora, Burkut, Magura, Marmarosh and Pieniny covers was studied that in the north-western sector of the Ukrainian Carpathians near the border of Poland and Slovakia (Lemkivsky segment) distinguish themselves by very inclined thrusts. Spatially the given tectonic units are within the limits of so called hydrothermal field unfavourable as a whole, as to the presence of hydrocarbons on a large scale here. But there were distinguished small plots with prevalence of hydrocarbons in the gas composition. Prospects of the potential for gas presence in the region should be connected with the areas that spatially gravitate towards Transcarpathian deep. Studied area consists of several tectonic units of the first order. These are covers located farther south-west of Krosno cover: Duklya-Chornohora, Burkut (Porkulets), Magura, Marmarosh and Pieniny covers, in the south-west the studied terrane is limited by the Transcarpathian deep, and farther west – by the state border of Ukraine and Slovakia, in the south-east – by the Rika Rriver, in the north-east – by the zone of joining of Duklya-Chornohora and Krosno covers. Prospects of the potential for oil end gas presence in the given area, as in the Folded Carpathians on the whole, should be determined by the complex of all accompanying parameters: structural, collecting and covering, hadrochemical and geochemical. For the given area of the Carpathians the geochemical factor is the most important.

Mazatzal–Labradorian-age (1.7–1.6 Ga) ductile deformation of the South Range Sudbury impact structure at the Thayer Lindsley mine, Ontario

2004 ◽  
Vol 41 (12) ◽  
pp. 1491-1505 ◽  
Author(s):  
J Bailey ◽  
B Lafrance ◽  
A M McDonald ◽  
J S Fedorowich ◽  
S Kamo ◽  
...  
Keyword(s):  
Shear Zone ◽  
Shear Bands ◽  
Shear Zones ◽  
Ductile Deformation ◽  
Impact Structure ◽  
The South ◽  
Tectonic Event ◽  
Southern Province ◽  
Sudbury Igneous Complex ◽  
Shear Sense

The Thayer Lindsley mine is located in the South Range of the Sudbury impact structure, near the contact between the 1.85 Ga Sudbury Igneous Complex (SIC) and the Paleoproterozoic Southern Province. Ni–Cu ore zones at the mine are strongly deformed within a southeast-dipping, lower amphibolite-grade shear zone, which offsets the contact between the SIC and Southern Province rocks. Numerous shear sense indicators, including shear bands, drag folds, and δ- and σ-type rotated porphyroclasts, consistently indicate south-over-north, reverse, dip-slip movement parallel to the mineral stretching lineation in the shear zone. The attitude, slip direction, and metamorphic grade of the shear zone are similar to those of the regional northeast-striking South Range Shear Zone that formed during post-impact, northwest-directed ductile contraction of the Sudbury impact structure. The South Range Shear Zone is generally interpreted as a ca. 1.9–1.8 Ga Penokean structure. Anhedral brown titanite grains from the Thayer Lindsley shear zone yield a mean 207Pb/206Pb Penokean age of 1815 ± 15 Ma. These grains are mantled by younger, syntectonic, colourless titanite, which have a mean 207Pb/206Pb age of 1658 ± 68 Ma. This younger age suggests that the South Range and Thayer Lindsley shear zones may have formed during a 1.7–1.6 Ga collisional tectonic event that is recorded along the southeast margin of Laurentia from the southwest USA. (Mazatzal Orogeny), through the mid-continent to Wisconsin, and as far northeast as Labrador (Labradorian Orogeny). 40Ar/39Ar analyses indicate post-tectonic thermal resetting of biotite occurred at 1477 ± 8 Ma during felsic plutonism across the Sudbury area.

scholarly journals Regional 3D geophysical investigation of the Sudbury Structure

2015 ◽  
Vol 3 (2) ◽  
pp. SL63-SL81 ◽  
Author(s):  
Oladele Olaniyan ◽  
Richard S. Smith ◽  
Bruno Lafrance
Keyword(s):  
Large Scale ◽  
Gravity Data ◽  
Normal Faults ◽  
Rift System ◽  
Geophysical Investigation ◽  
Orientation Data ◽  
Sudbury Igneous Complex ◽  
Sudbury Structure ◽  
New Interpretation ◽  
Seismic Sections

The 3D geologic and structural setting of the Sudbury Structure was predicted by an integration of surface and subsurface geologic data with 2.5D modeling of high-resolution airborne magnetic and gravity data using 3D GeoModeller software. Unlike other CAD-based 3D software, GeoModeller uses the field interpolator method, whereby contacts of rock units are assumed to be equipotential surfaces, whereas orientation data determine the gradient and direction of the surfaces. Contacts and orientation variables are cokriged to generate 3D continuous surfaces for each geologic unit. Our 3D geologic model was qualitatively evaluated by forward computing the predicted gravity response at 1 m above topography and by comparing this response to the measured gravity field. Large-scale structures within the Onaping Formation and Archean basement, which overlie and underlie the Sudbury Igneous Complex (SIC), respectively, were not the cause of the linear gravity high in the center of the Sudbury Structure. We suggested that the deformation of the initial circular SIC may have commenced under the Sudbury Basin due to the reversal of the normal faults related to the Huronian rift system during the Penokean orogeny, therefore resulting into a north verging fold at the base of the SIC in the south range. This new interpretation was consistent with the magnetic and gravity data and honoured most of the significant seismic reflectors in the Lithoprobe seismic sections.

Characterising essential breeding habitat for whales informs the development of large-scale Marine Protected Areas in the South Pacific

2016 ◽  
Vol 548 ◽  
pp. 263-275 ◽  
Author(s):  
RE Lindsay ◽  
R Constantine ◽  
J Robbins ◽  
DK Mattila ◽  
A Tagarino ◽  
...  
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Large Scale ◽  
South Pacific ◽  
Breeding Habitat ◽  
The South

MODELING THE SOUTH ATLANTIC OCEAN FROM MEDIUM TO HIGH RESOLUTION

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Mariela Gabioux ◽  
Vladimir Santos da Costa ◽  
Joao Marcos Azevedo Correia de Souza ◽  
Bruna Faria de Oliveira ◽  
Afonso De Moraes Paiva
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Large Scale ◽  
South Atlantic ◽  
Surface Relaxation ◽  
The South ◽  
Small Surface ◽  
Basic Model ◽  
Basic Set ◽  
Set Up

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.

scholarly journals Examination of Construct Validity and Criterion-Related Validity of the German Motor Test in Egyptian Schoolchildren

2021 ◽  
Vol 18 (16) ◽  
pp. 8341
Author(s):  
Osama Abdelkarim ◽  
Julian Fritsch ◽  
Darko Jekauc ◽  
Klaus Bös
Keyword(s):  
Construct Validity ◽  
Physical Fitness ◽  
Large Scale ◽  
Body Height ◽  
Cross Sectional Study ◽  
Latent Factors ◽  
Cross Sectional ◽  
First Order ◽  
Motor Test ◽  
Health Related

Physical fitness is an indicator for children’s public health status. Therefore, the aim of this study was to examine the construct validity and the criterion-related validity of the German motor test (GMT) in Egyptian schoolchildren. A cross-sectional study was conducted with a total of 931 children aged 6 to 11 years (age: 9.1 ± 1.7 years) with 484 (52%) males and 447 (48%) females in grades one to five in Assiut city. The children’s physical fitness data were collected using GMT. GMT is designed to measure five health-related physical fitness components including speed, strength, coordination, endurance, and flexibility of children aged 6 to 18 years. The anthropometric data were collected based on three indicators: body height, body weight, and BMI. A confirmatory factor analysis was conducted with IBM SPSS AMOS 26.0 using full-information maximum likelihood. The results indicated an adequate fit (χ2 = 112.3, df = 20; p < 0.01; CFI = 0.956; RMSEA = 0.07). The χ2-statistic showed significant results, and the values for CFI and RMSEA showed a good fit. All loadings of the manifest variables on the first-order latent factors as well as loadings of the first-order latent factors on the second-order superordinate factor were significant. The results also showed strong construct validity in the components of conditioning abilities and moderate construct validity in the components of coordinative abilities. GMT proved to be a valid method and could be widely used on large-scale studies for health-related fitness monitoring in the Egyptian population.

scholarly journals Simulations of a bubble wall interacting with an electroweak plasma

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Zong-Gang Mou ◽  
Paul M. Saffin ◽  
Anders Tranberg
Keyword(s):  
Large Scale ◽  
Baryon Asymmetry ◽  
Winding Number ◽  
Bubble Wall ◽  
Electroweak Phase Transition ◽  
First Order ◽  
The Standard Model ◽  
Technical Details ◽  
Real Time Simulations ◽  
Chern Simons

Abstract We perform large-scale real-time simulations of a bubble wall sweeping through an out-of-equilibrium plasma. The scenario we have in mind is the electroweak phase transition, which may be first order in extensions of the Standard Model, and produce such bubbles. The process may be responsible for baryogenesis and can generate a background of primordial cosmological gravitational waves. We study thermodynamic features of the plasma near the advancing wall, the generation of Chern-Simons number/Higgs winding number and consider the potential for CP-violation at the wall generating a baryon asymmetry. A number of technical details necessary for a proper numerical implementation are developed.

scholarly journals Crustal variability along the rifted/sheared East African margin: a review

2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Maren Vormann ◽  
Wilfried Jokat
Keyword(s):  
East Africa ◽  
Shear Zone ◽  
Structural Changes ◽  
The South ◽  
East African ◽  
The North ◽  
Rifted Margins ◽  
Continental Block ◽  
Seismic Lines ◽  
Southeastern Madagascar

AbstractThe East African margin between the Somali Basin in the north and the Natal Basin in the south formed as a result of the Jurassic/Cretaceous dispersal of Gondwana. While the initial movements between East and West Gondwana left (oblique) rifted margins behind, the subsequent southward drift of East Gondwana from 157 Ma onwards created a major shear zone, the Davie Fracture Zone (DFZ), along East Africa. To document the structural variability of the DFZ, several deep seismic lines were acquired off northern Mozambique. The profiles clearly indicate the structural changes along the shear zone from an elevated continental block in the south (14°–20°S) to non-elevated basement covered by up to 6-km-thick sediments in the north (9°–13°S). Here, we compile the geological/geophysical knowledge of five profiles along East Africa and interpret them in the context of one of the latest kinematic reconstructions. A pre-rift position of the detached continental sliver of the Davie Ridge between Tanzania/Kenya and southeastern Madagascar fits to this kinematic reconstruction without general changes of the rotation poles.

scholarly journals Mercury spikes as evidence of extended arc-volcanism around the Devonian–Carboniferous boundary in the South Tian Shan (southern Uzbekistan)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michał Rakociński ◽  
Agnieszka Pisarzowska ◽  
Carlo Corradini ◽  
Katarzyna Narkiewicz ◽  
Zofia Dubicka ◽  
...  
Keyword(s):  
Big Five ◽  
Mass Extinction ◽  
First Record ◽  
Black Shales ◽  
The South ◽  
Arc Volcanism ◽  
First Order ◽  
Marine Deposits ◽  
High Mercury ◽  
Tian Shan

AbstractRecently, the end-Devonian mass extinction (Hangenberg Crisis, 359 Ma) was identified as a first-order mass extinction, albeit not one of the “Big Five” events. Many marine and terrestrial organisms were affected by this crisis. The cause of this mass extinction is still conjectural and widely discussed. Here we report anomalously high mercury (Hg) concentrations from the South Tian Shan (Uzbekistan), together with correlation using conodont biostratigraphic data. Hg enrichment (to 5825 ppb) was detected in marine deposits encompassing the Hangenberg Crisis. In the Novchomok section, the Hangenberg Crisis interval does not contain typical Hangenberg Black Shales; however, by means of inorganic geochemistry (enrichment of redox-sensitive elements such as Mo, V, and U) we detected an equivalent level despite the lack of marked facies changes. This is the first record of Hg and Hg/total organic carbon anomalies in marly shales, marls and carbonates that are totally independent of facies changes, implying that volcanism was the most probable cause of the Hangenberg Crisis. This conclusion is confirmed by the presence of a negative δ13C excursion, which may reflect massive release of isotopically light carbon from volcanogenic and thermogenic devolatilization likely combined with increased arc-volcanism activity worldwide at the end of the Devonian.

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