scholarly journals The role of oxidation-reduction and C-H-O fluids in determining melting conditions and magma compositions in the upper mantle

1990 ◽  
Vol 99 (1) ◽  
pp. 153-165 ◽  
Author(s):  
D H Green
Keyword(s):  
Upper Mantle ◽  
Oxidation Reduction ◽  
Magma Compositions ◽  
Melting Conditions

The role of changes in oxidation reduction status within dexamethasone-induced apoptosis in Jurkat tumor cells

2021 ◽  
Vol 172 (10) ◽  
pp. 479-482
Author(s):  
О. L. Nosareva ◽  
◽  
E. A. Stepovaya ◽  
E. V. Shakhristova ◽  
R. M. Karpov ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Oxidation Reduction ◽  
Induced Apoptosis

Plumbing and architecture of a crustal mineralizing system in the Archean Superior Province, Canada

2021 ◽  
Author(s):  
Eric Roots ◽  
Graham Hill ◽  
Ben M. Frieman ◽  
James A. Craven ◽  
Richard S. Smith ◽  
...  
Keyword(s):  
Upper Mantle ◽  
Spatial Association ◽  
Three Dimensional ◽  
3D Models ◽  
Superior Province ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Abitibi Subprovince ◽  
Lower Crustal

<p>The role of melts and magmatic/metamorphic fluids in mineralization processes is well established. However, the role of crustal architecture in defining source and sink zones in the middle to lower crust remains enigmatic. Integration of three dimensional magnetotelluric (MT) modelling and seismic reflection data across the Archean Abitibi greenstone belt of the Superior Province, Canada, reveals a ‘whole-of-crust’ mineralizing system and highlights the controls by crustal architecture on metallogenetic processes. Electrically conductive conduits in an otherwise resistive upper crust are coincident with truncations and offsets of seismic reflections that are mostly interpreted as major brittle-ductile fault zones. The spatial association between these features and low resistivity zones imaged in the 3D models suggest that these zones acted as pathways through which fluids and melts ascended toward the surface. At mid-crustal levels, these ‘conduit’ zones connect to ~50 km long, north-south striking conductors, and are inferred to represent graphite and/or sulphide deposited from cooling fluids. At upper mantle to lower crustal depths, east-west trending conductive zones dominate and display shallow dips. The upper mantle features are broadly coincident with the surface traces of the major deformation zones with which a large proportion of the gold endowment is associated. We suggest that these deep conductors represent interconnected graphitic zones perhaps augmented by sulphides that are relicts from metamorphic fluid and melt emplacement associated primarily with the later stages of regional deformation.  Thus, from the combined MT and seismic data, we develop a crustal-scale architectural model that is consistent with existing geological and deformational models, providing constraints on the sources for and signatures of fluid and magma emplacement that resulted in widespread metallogenesis in the Abitibi Subprovince.</p>

Semi-brittle behavior of wet olivine aggregates: the role of aqueous fluid in faulting at upper mantle pressures

2018 ◽  
Vol 173 (10) ◽  
Author(s):  
Tomohiro Ohuchi ◽  
Xinglin Lei ◽  
Yuji Higo ◽  
Yoshinori Tange ◽  
Takeshi Sakai ◽  
...  
Keyword(s):  
Upper Mantle ◽  
Aqueous Fluid ◽  
Brittle Behavior

3. Minerals and the interior of the Earth

2014 ◽  
Author(s):  
David Vaughan
Keyword(s):  
Upper Mantle ◽  
Lower Mantle ◽  
Plate Tectonics ◽  
Inner Core ◽  
Indirect Evidence ◽  
Outer Core ◽  
The Earth ◽  
Granite Formation ◽  
Temperature And Pressure

‘Minerals and the interior of the Earth’ looks at the role of minerals in plate tectonics during the processes of crystallization and melting. The size and range of minerals formed are dependent on the temperature and pressure of the magma during its movement through the crust. The evolution of the continental crust also involves granite formation and processes of metamorphism. Our understanding of the interior of the Earth is based on indirect evidence, mainly the study of earthquake waves. The Earth consists of concentric shells: a solid inner core; liquid outer core; a solid mantle divided into a lower mantle, a transition zone, and an upper mantle; and then the outer rigid lithosphere.

On the theory of electron-transfer processes in aqueous solutions

1954 ◽  
Vol 222 (1148) ◽  
pp. 128-141 ◽  
Keyword(s):  
Electron Transfer ◽  
Point Of View ◽  
Complex Ions ◽  
Gaseous State ◽  
Biochemical Processes ◽  
Transfer Processes ◽  
Oxidation Reduction ◽  
Mechanical Interpretation ◽  
Electron Transfer Processes

It has been realized for some time that simple electron-transfer processes play an important part in the mechanism of many oxidation-reduction reactions in solution. An attempt has been made to give a quantum-mechanical interpretation of these processes on the basis of the earlier theories of electron transfer in the gaseous state (Landau 1932; Bates & Massey 1943). The present treatment for solutions takes into account the role of the solvent, with particular reference to the operation of the Franck—Condon principle and it also leads to some definite picture of the transition state for the electron transfer process. A number of examples are discussed, including electron transfer between like ions of different valency and also reactions involving complex ions, e.g. metal porphyrins, the reactions of which are of importance in certain biochemical processes. It appears that the application of certain theoretical principles leads to a satisfactory understanding of electron-transfer processes in solution from a qualitative and, in some cases, also from a semi-quantitative point of view.

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