Stratigraphy and uranium content of the Chattanooga shale in northeastern Alabama, northwestern Georgia, and eastern Tennessee

1959 ◽  
Keyword(s):  
Uranium Content ◽  
Chattanooga Shale

scholarly journals The Study of Uranium Accumulation in Marine Bottom Sediments: Effect of Redox Conditions at the Time of Sedimentation

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 332
Author(s):  
Nadezhda Khaustova ◽  
Yulia Tikhomirova ◽  
Svetlana Korost ◽  
Elena Poludetkina ◽  
Andrey Voropaev ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
White Sea ◽  
Uranium Content ◽  
Black Shales ◽  
Redox Conditions ◽  
Source Rocks ◽  
Shelf Zone ◽  
The Black Sea ◽  
The White Sea ◽  
Run Off

To evaluate the effect of redox conditions at the sedimentation stage on uranium content and U/TOC ratio in marine source rocks, we analyzed the accumulation of uranium in modern marine bottom sediments formed in different redox conditions. The behavior of uranium from bottom sediments formed in oxidizing and sub-oxidizing settings has been studied on the sediments of the Upper Pleistocene–Holocene age accumulated in the coastal area of the White Sea (Kandalaksha Gulf). We studied the content of uranium, Eh, pH, TOC, C, H, N, and S element and isotope compositions and other parameters in two sampled columns of bottom sediments at a depth of 0–2.5 m. The composition of sediments was typical for the shelf zone where marine genesis mixes with the continental run-off. The upper layer of sediments (0–50 cm) were characterized by oxidizing conditions (Eh ~ 400 mV); with the increase in depth, redox conditions changed from oxidizing to reducing (0 ÷ 200 mV). The uranium concentration in the upper layer was 1–1.5 ppm, U/TOC ratio varied in the range of 0.8–1.1 ppmU/%TOC. The uranium content and U/TOC ratio increased up to the values of 2.6 ppm and 1.4 ppmU/%TOC at a depth of 0.5−2.5 m, respectively, but the general content of uranium in the studied environment was close to the values characterizing continental run-off. The results obtained for the White Sea sediments were compared with the sediment of the Black Sea, formed in the anoxic conditions of hydrogen sulfide contamination. In these conditions, the uranium content varied from 10 to 20 ppm. The obtained data were interpreted using thermodynamic modeling of the uranium forms in the seawater at different pH and Eh. This study demonstrated that the change of redox conditions from oxidizing to reducing leads to increased uranium content due to a decrease in uranium’s solubility in water. These results show that oxidation–reduction potential could be one of the most important factors controlling uranium content in black shales formed in the marine environment.

scholarly journals Construction of new houses on a uranium vein outcrop: a case study from the Czech Republic

Nukleonika ◽  
2016 ◽  
Vol 61 (3) ◽  
pp. 343-349 ◽  
Author(s):  
Viktor Goliáš ◽  
Gereltsetseg Tumurkhuu ◽  
Pavel Kohn ◽  
Ondřej Šálek ◽  
Jakub Plášil ◽  
...  
Keyword(s):  
Planning Process ◽  
Uranium Content ◽  
Uranium Mineralization ◽  
Construction Site ◽  
The Czech Republic ◽  
Uranium Ore ◽  
Safety Requirements ◽  
New Construction ◽  
Radon Risk

Abstract Significant uranium mineralization represented by a typical assemblage of uranyl supergene minerals in a quartz-uraninite vein hosted in the exocontact zone of the Variscan-Tanvald granite was found at a new construction site in the municipality of Jablonec n. Nisou. Activities of 222Rn in soil gas reached 1 MBq/m3 around two houses, with a maximum of 3.33 MBq/m3 between them on a uranium ore lens outcrop. The uranium content reaches up to 291 ppm eU (3595 Bq/kg 226Ra), and it is possible to find many ‘hot’ pieces of uranium ore fragments with a high percentage of uranium in the Quaternary cover in this place. This unfavourable situation is a result of an improper spatial planning process. The constructor was given the permission to construct the building even though the construction site did not meet safety requirements and the geological survey had failed. Not only geological prospecting was underestimated, but also the radon risk assessment was undervalued.

Sign in / Sign up

Export Citation Format

Share Document