scholarly journals Audio-magnetotelluric investigation of sulfide mineralization in Proterozoic–Archean greenstone belts of Eastern Indian Craton

2018 ◽  
Vol 127 (3) ◽  
Author(s):  
Shailendra Singh ◽  
Ved P Maurya ◽  
Roshan K Singh ◽  
Shalivahan Srivastava ◽  
Anurag Tripathi ◽  
...  
Keyword(s):  
Sulfide Mineralization ◽  
Indian Craton ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

Rubidium–strontium ages from the Oxford Lake – Knee Lake greenstone belt, northern Manitoba

1980 ◽  
Vol 17 (5) ◽  
pp. 560-568 ◽  
Author(s):  
G. S. Clark ◽  
S.-P. Cheung
Keyword(s):  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Superior Province ◽  
Granitic Intrusion ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

Rb–Sr whole-rock ages have been determined for rocks from the Oxford Lake – Knee Lake – Gods Lake greenstone belt, in the Superior Province of northeastern Manitoba.The age of the Magill Lake Pluton is 2455 ± 35 Ma (λ87Rb = 1.42 × 10−11 yr−1), with an initial 87Sr/86Sr ratio of 0.7078 ± 0.0043. This granitic stock intrudes the Oxford Lake Group, so it is post-tectonic and probably related to the second, weaker stage of metamorphism.The age of the Bayly Lake Pluton is 2424 ± 74 Ma, with an initial 87Sr/86Sr ratio of 0.7029 ± 0.0001. This granodioritic batholith complex does not intrude the Oxford Lake Group. It is syn-tectonic and metamorphosed.The age of volcanic rocks of the Hayes River Group, from Goose Lake (30 km south of Gods Lake Narrows), is 2680 ± 125 Ma, with an initial 87Sr/86Sr ratio of 0.7014 ± 0.0009.The age for the Magill Lake and Bayly Lake Plutons can be interpreted as the minimum ages of granitic intrusion in the area.The age for the Hayes River Group volcanic rocks is consistent with Rb–Sr ages of volcanic rocks from other Archean greenstone belts within the northwestern Superior Province.

What drives metamorphism in early Archean greenstone belts? Insights from numerical modeling

2018 ◽  
Vol 746 ◽  
pp. 587-601 ◽  
Author(s):  
Elena Sizova ◽  
Taras Gerya ◽  
Michael Brown ◽  
Kurt Stüwe
Keyword(s):  
Numerical Modeling ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

scholarly journals Geochemistry of komatiites and basalts in Archean greenstone belts of Russian Karelia with emphasis on platinum-group elements

2019 ◽  
Vol 55 (5) ◽  
pp. 971-990 ◽  
Author(s):  
Fang-Fang Guo ◽  
Sergei Svetov ◽  
Wolfgang D. Maier ◽  
Eero Hanski ◽  
Sheng-Hong Yang ◽  
...  
Keyword(s):  
Platinum Group Elements ◽  
Greenstone Belts ◽  
Platinum Group ◽  
Archean Greenstone Belts ◽  
Russian Karelia

Archean greenstone belts

1982 ◽  
Vol 18 (1) ◽  
pp. 95-96
Author(s):  
D. Robinson
Keyword(s):  
Greenstone Belts ◽  
Archean Greenstone Belts

Patterns of total and incremental strain in subsiding troughs: experimental centrifuged. models of inter-diapir synclines

1983 ◽  
Vol 20 (12) ◽  
pp. 1843-1861 ◽  
Author(s):  
J. M. Dixon ◽  
J. M. Summers
Keyword(s):  
Surface Deformation ◽  
Main Body ◽  
Gneiss Domes ◽  
Strain Pattern ◽  
Vertical Extension ◽  
Greenstone Belts ◽  
Vertical Gravity ◽  
Incremental Strain ◽  
Archean Greenstone Belts ◽  
Model Structures

The experimental technique of centrifuge modelling has been used to elucidate patterns of total strain and progressive deformation associated with troughs that form by gravitational subsidence of a dense cover into a less dense basement. Model structures are analogous to synclines found between mantled gneiss domes, and the models provide data with which to test the hypothesis that Archean greenstone belts are products of vertical gravity tectonics.Experimental results include the following. (1) Strain within the main body of subsiding belts is dominated by strong horizontal contraction and vertical extension. In natural structures this strain pattern would produce vertical foliation and steeply plunging mineral lineation. (2) Within cover units near trough margins the flattening plane trends parallel with or at a low angle to the cover–basement interface at all levels in the trough. (3) Patterns of strain within subsiding troughs, at least as expressed in surface deformation, reflect the geometry of the cover–basement interface at depth. Flow within the cover units converges towards points of maximum trough subsidence to produce local vertical constrictive strain. Deformation above trough saddles is characterized by vertical flattening strain. (4) Horizontal shortening within a subsiding, stratified cover sequence produces early folds with horizontal axes and steep axial surfaces. Where the stratified sequence forms a relatively low-density unit within the cover, folds and thrusts verge consistently away from the trough axis. Continued subsidence and horizontal contraction tend to rotate initially shallowly dipping structures into steeply dipping attitudes.

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