Results 81 to 90 of about 26,623 (334)

Reservoir theory for studying the geochemical evolution of soils [PDF]

open access: yes, 2010
[1] Linking mineral weathering rates measured in the laboratory to those measured at the landscape scale is problematic. In laboratory studies, collections of minerals are exposed to the same weathering environment over a fixed amount of time. In natural
Almond   +58 more
core   +2 more sources

Neoarchean Arc Magmatism and Crust Recycling in the Northern Marginal Zone of the Limpopo Complex, Zimbabwe: New Insights From Zircon U‐Pb‐Hf Isotopes of a Charnockite Suite

open access: yesGeological Journal, EarlyView.
Charnockites with 2691–2607 Ma magmatic ages from the NMZ show arc‐magmatic geochemical signatures. They correspond to the lower‐crustal equivalent of the Chilimanzi Suite Granite in the Zimbabwe Craton. Lu‐Hf isotopic data of magmatic zircons show negative εHf(t) values (−11.18 to −2.20) with TDMC ages of 3699–3158 Ma, suggesting their protolith ...
Toshiaki Tsunogae   +6 more
wiley   +1 more source

Petrogenesis and tectonic implications of intrusive rocks in the Jiangjunmu porphyry deposit, East Kunlun orogeny, NW China

open access: yesFrontiers in Earth Science
The newly discovered Jiangjunmu Cu–Au deposits are hosted within granodiorite porphyry and K-feldspar granite of the East Kunlun metallogenic belt. Previous understanding of these deposits has been limited due to a lack of comprehensive isotopic data. To
Yu Junzhen   +12 more
doaj   +1 more source

Asteroid Cooling Rates Indicated by K-Feldspar Exsolution Textures in H4 Ordinary Chondrites [PDF]

open access: yes
Undisturbed thermal metamorphism in ordinary chondrite (OC) asteroids, produced through the radioactive decay of 26Al, is expected to result in an onion-shell-like structure. In such a structure, the inner layers of the asteroid experience more extensive
Christoffersen, R. G.   +2 more
core   +1 more source

High‐Titanium Zircon Rims in Rhyolite – A Reflection of Adiabatic Ascent?

open access: yesGeological Journal, EarlyView.
The ascent of granitic magma from source to emplacement is rapidly achieved through dyking, resulting in negligible heat loss to the surrounding wallrock (i.e., adiabatic). Zircon growth during ascent can record the changing magma conditions including adiabatic cooling and heating, resulting in high titanium rims on low titanium cores without ...
Carson Kinney   +2 more
wiley   +1 more source

Study on the characteristics of rubidium and cesium carrier minerals in the beneficiation process of lithium-bearing clay

open access: yesResults in Engineering
Rubidium (Rb) and cesium (Cs), as rare alkali metals, play a critical role in high-tech industries. However, their efficient extraction from associated mineral resources is challenging, especially in lithium-bearing clays due to fine-grained ...
Keqiang Chen   +7 more
doaj   +1 more source

Pb-Zn and minor U mineralization at Tyndrum, Scotland. [PDF]

open access: yes, 1985
This mineralization occurs as veins and vein breccias in fractures associated with the Tyndrum-Glen Fyne fault. Quartz, galena and sphalerite, with minor chalcopyrite and baryte, are accompanied by small inclusions (in the galena-rich veins) of ...
Bethke   +14 more
core   +1 more source

Evidence From Microscopy and U–Pb Geochronology as a Clue to the Influence of the Cretaceous Magmatism in the Diagenesis of Pre‐Salt Carbonate Reservoirs in the Santos Basin (Brazil)

open access: yesGeological Journal, EarlyView.
Carbonates from Santos Basin revealed U–Pb ages correlated with basalt ages (A), suggesting that they were formed during magmatic events. These events placed hot CO2 in the reservoir, which, when mixed with carbonate‐rich cold water (B), led to thermal convection, enabling the formation of the U contained in the carbonates.
Marco António Ruivo de Castro e Brito   +8 more
wiley   +1 more source

Khirbet al-Batrawy ceramics. A systematic mineralogical and petrographic study for investigating the material culture [PDF]

open access: yes, 2017
The present paper reports the results of a mineralogical and petrographic study focused on the archaeometric characterization of Early Bronze Age pottery from the archaeological site of Khirbet al-Batrawy (Jordan), dated between 3000 and 2000 BC. Optical
Medeghini, Laura, Nigro, Lorenzo
core   +1 more source

Does Palsa Thaw in Northern Finland Contribute to Remobilisation of Metals Accumulated in Peat Into Surface Waters?

open access: yesLand Degradation &Development, EarlyView.
ABSTRACT Permafrost is rapidly degrading in the sporadic zone, including palsa mires in Scandinavia. Peatlands in the area have likely accumulated heavy metals from atmospheric deposition of industrial contaminants in the wider region. As the palsa mire chemical composition is not well known, and in other permafrost regions the permafrost thaw may ...
Joanna Katarzyna Jóźwik   +7 more
wiley   +1 more source

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