scholarly journals Magnetite composition as petrogenetic and prospectivity indicator for FE-TI-V-P mineralization in Archean mafic-ultramafic intrusions within the Superior Province, Ontario and Quebec

2021 ◽  
Author(s):  
A -A Sappin ◽  
M G Houlé
2021 ◽  
Vol 13 (10) ◽  
pp. 5612
Author(s):  
Shu-Yuan Pan ◽  
Cheng-Di Dong ◽  
Jenn-Feng Su ◽  
Po-Yen Wang ◽  
Chiu-Wen Chen ◽  
...  

Biochar is a carbon-rich material prepared from the pyrolysis of biomass under various conditions. Recently, biochar drew great attention due to its promising potential in climate change mitigation, soil amendment, and environmental control. Obviously, biochar can be a beneficial soil amendment in several ways including preventing nutrients loss due to leaching, increasing N and P mineralization, and enabling the microbial mediation of N2O and CO2 emissions. However, there are also conflicting reports on biochar effects, such as water logging and weathering induced change of surface properties that ultimately affects microbial growth and soil fertility. Despite the voluminous reports on soil and biochar properties, few studies have systematically addressed the effects of biochar on the sequestration of carbon, nitrogen, and phosphorus in soils. Information on microbially-mediated transformation of carbon (C), nitrogen (N), and phosphorus (P) species in the soil environment remains relatively uncertain. A systematic documentation of how biochar influences the fate and transport of carbon, phosphorus, and nitrogen in soil is crucial to promoting biochar applications toward environmental sustainability. This report first provides an overview on the adsorption of carbon, phosphorus, and nitrogen species on biochar, particularly in soil systems. Then, the biochar-mediated transformation of organic species, and the transport of carbon, nitrogen, and phosphorus in soil systems are discussed. This review also reports on the weathering process of biochar and implications in the soil environment. Lastly, the current knowledge gaps and priority research directions for the biochar-amended systems in the future are assessed. This review focuses on literatures published in the past decade (2009–2021) on the adsorption, degradation, transport, weathering, and transformation of C, N, and P species in soil systems with respect to biochar applications.


2010 ◽  
Vol 44 (11) ◽  
pp. 3487-3495 ◽  
Author(s):  
Jeroen J.M. Geurts ◽  
Alfons J.P. Smolders ◽  
Artur M. Banach ◽  
Jan P.M. van de Graaf ◽  
Jan G.M. Roelofs ◽  
...  

1980 ◽  
Vol 17 (5) ◽  
pp. 560-568 ◽  
Author(s):  
G. S. Clark ◽  
S.-P. Cheung

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.


2011 ◽  
Vol 48 (2) ◽  
pp. 187-204 ◽  
Author(s):  
Gary P. Beakhouse ◽  
Shoufa Lin ◽  
Sandra L. Kamo

The Neoarchean Pukaskwa batholith consists of pre-, syn-, and post-tectonic phases emplaced over an interval of 50 million years. Pre-tectonic phases are broadly synvolcanic and have a high-Al tonalite–trondhjemite–granodiorite (TTG) affinity interpreted to reflect derivation by partial melting of basaltic crust at lower crustal or upper mantle depths. Minor syn-tectonic phases slightly post-date volcanism and have geochemical characteristics suggesting some involvement or interaction with an ultramafic (mantle) source component. Magmatic emplacement of pre- and syn-tectonic phases occurred in the midcrust at paleopressures of 550–600 MPa and these components of the batholith are thought to be representative of the midcrust underlying greenstone belts during their development. Subsequent to emplacement of the syntectonic phases, and likely at approximately 2680 Ma, the Pukaskwa batholith was uplifted as a structural dome relative to flanking greenstone belts synchronously with ongoing regional sinistral transpressive deformation. The driving force for vertical tectonism is interpreted to be density inversion (Rayleigh–Taylor-type instabilities) involving denser greenstone belts and underlying felsic plutonic crust. The trigger for initiation of this process is interpreted to be an abrupt change in the rheology of the midcrust attributed to introduction of heat from the mantle attendant with slab breakoff or lithospheric delamination following the cessation of subduction. This process also led to partial melting of the intermediate to felsic midcrust generating post-tectonic granitic phases at approximately 2667 Ma. We propose that late density inversion-driven vertical tectonics is an inevitable consequence of horizontal (plate) tectonic processes associated with greenstone belt development within the Superior Province.


Sign in / Sign up

Export Citation Format

Share Document