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The Other Energy Sources
Published in Anco S. Blazev, Power Generation and the Environment, 2021
The processes which transferred uranium from the mantle to the continental crust are complex and consist of many consequent steps over a long time period, but for the past 2 billion years they have involved: Formation of oceanic crust and lithosphere through melting of the mantle at mid-ocean ridges.Migration of this oceanic lithosphere laterally to a site of plate consumption (this is marked at the surface by a deep-sea trench).Production of fluids and magmas from the down-going (subducted) lithospheric plate and overriding mantle “wedge” in these subduction zones.Transfer of these fluids/melts to the surface in zones of “island arcs” (such as the Pacific’s Ring of Fire).Production of continental crust from these island arc protoliths, through re-melting, granite formation and intra-crustal recycling.
The Other Energy Markets
Published in Anco S. Blazev, Global Energy Market Trends, 2021
It took over 2 billion years to go through the: Formation of oceanic crust and lithosphere through melting of the mantle at mid-ocean ridges,Migration of the oceanic lithosphere laterally to a site of plate consumption (this is marked at the surface by a deep-sea trench),Production of fluids and magmas from the down-going (subducted) lithospheric plate and overriding mantle “wedge” in these subduction zones,Transfer of these fluids/melts to the surface in zones of “island arcs” (such as the Pacific’s Ring of Fire),Production of continental crust from the island arc protoliths, through re-melting, granite formation and intracrustal recycling.In nature, uranium ore is found as uranium-238 (99.27%), uranium-235 (0.72%), and a very small amount of uranium-234 (0.006%).
Magmatism in the Context of the Present-Day Tectonic Settings
Published in O.A. Bogatikov, R.F. Fursenko, G.V. Lazareva, E.A. Miloradovskaya, A. Ya, R.E. Sorkina, Magmatism and Geodynamics Terrestrial Magmatism Throughout the Earth’s History, 2020
O.A. Bogatikov, V.I. Kovalenko, E.V. Sharkov, V.V. Yarmolyuk
In terms of plate tectonics the Benioff zone corresponds with a lithospheric slab (80–100 km thick) which is being subducted into the mantle. At a certain depth the subducting plate material dewaters and melts by injection of the melt and volatiles into the mantle wedge, resulting in partial melting, the intrusion of magma into the upper crust, and volcanism.
The “intraorogenic” Svecofennian Herräng mafic dyke swarm in east-central Sweden: age, geochemistry and tectonic significance
Published in GFF, 2020
Åke Johansson, Andreas Karlsson
A very schematic drawing outlining a tentative model for the formation of the Herräng dykes is shown in Figure 15. A mantle source that had undergone long-term depletion in incompatible elements subsequently became enriched in these elements by subduction-induced fluids and melts that affected the mantle wedge above a subduction zone (cf. Andersson et al. 2007; Rutanen & Andersson 2009; Johansson et al. 2012; Johansson & Hålenius 2013; Dahlin et al. 2014, and references therein). It is possible that fluid-enriched and melt-enriched components occurred physically separate, e.g., at different depths, or intermingled as different mineral phases within the same domain. In either case, these may have reacted somewhat differently during partial melting, giving rise to magmas with slightly different degrees of enrichment in different elements (LREE versus HREE, or LILE versus HFSE).
The isotope geochemistry of host rocks of the late Archean Guandi and Banshigou banded iron formations, southern Jilin Province: temporal and tectonic significance
Published in Australian Journal of Earth Sciences, 2023
Previous studies have shown that dehydration reactions cause hydration of the mantle wedge and that the mantle wedge overlying the subducting slab partially melts upon an influx of water, causing volcanic arc magmatism (Maruyama et al., 2007; Zhao et al., 2007). According to our interpretation, the source magma may have been derived from depleted mantle wedge melts metasomatised by subduction-slab melts and contaminated by ancient crust.