Matches in SemOpenAlex for { <https://semopenalex.org/work/W2023863963> ?p ?o ?g. }
- W2023863963 endingPage "1039" @default.
- W2023863963 startingPage "1023" @default.
- W2023863963 abstract "Oxidizing conditions normally prevail in surface waters and near-surface groundwaters, but there is usually a change to reducing conditions in groundwater at greater depth. Dissolved O2 originally present is consumed through biogenic and inorganic reactions along the flow paths. Fracture minerals participate in these reactions and the fracture mineralogy and geochemistry can be used to trace the redox front. An important task in the safety assessment of a potential repository for the disposal of nuclear waste in crystalline bedrock, at an approximate depth of 500 m in Sweden, is to demonstrate that reducing conditions can be maintained for a long period of time. Oxygen may damage the Cu canisters that host nuclear waste; additionally, in the event of a canister failure, oxidizing conditions may increase the mobility of some radionuclides. The present study of the near-surface redox front is based on mineralogical (redox-sensitive minerals), geochemical (redox-sensitive elements) and U-series disequilibrium investigations of mineral coatings along open fractures. The fractures have been sampled along drill cores from closely spaced, 100 m deep boreholes, which were drilled during the site investigation work in the Laxemar area, south-eastern Sweden, carried out by the Swedish Nuclear Fuel and Waste Management Co. (SKB). The distribution of the redox-sensitive minerals pyrite and goethite in open fractures shows that the redox front (switch from mainly goethite to mainly pyrite in the fractures) generally occurs at about 15–20 m depth. Calcite leaching by recharging water is indicated in the upper 20–30 m and positive Ce-anomalies suggest oxidation of Ce down to 20 m depth. The U-series radionuclides show disequilibrium in most of the samples, indicating mobility of U during the last 1 Ma. In the upper 20 m, U is mainly removed (due to oxidation) or has experienced complex removal and/or deposition. At depths of 35–55 m, both deposition and removal of U are indicated. Below 55 m, recent deposition of U is generally indicated which suggests removal of U near surface (oxidation) and deposition of U below the redox front. Scattered goethite occurrences below the general redox front (down to ca 80 m) and signs of U removal at 35–55 m mostly correlate with sections of high transmissivity (and/or high fracture frequencies). This shows that highly transmissive fractures are generally required to allow oxygenated groundwaters at depth greater than ca 30 m. Removal of U (oxidation) below 55 m within the last 300 ka is not observed. Although penetration of glacial waters to great depths has been confirmed in the study area, their potential O2 load seems to have been reduced near the surface." @default.
- W2023863963 created "2016-06-24" @default.
- W2023863963 creator A5063976943 @default.
- W2023863963 creator A5076929971 @default.
- W2023863963 creator A5085499013 @default.
- W2023863963 date "2009-05-01" @default.
- W2023863963 modified "2023-09-27" @default.
- W2023863963 title "Detecting the near-surface redox front in crystalline bedrock using fracture mineral distribution, geochemistry and U-series disequilibrium" @default.
- W2023863963 cites W1973559604 @default.
- W2023863963 cites W1977039791 @default.
- W2023863963 cites W1977220521 @default.
- W2023863963 cites W1978866779 @default.
- W2023863963 cites W1984083585 @default.
- W2023863963 cites W1984307310 @default.
- W2023863963 cites W1985102170 @default.
- W2023863963 cites W1992708732 @default.
- W2023863963 cites W1993664081 @default.
- W2023863963 cites W1995205939 @default.
- W2023863963 cites W1997127228 @default.
- W2023863963 cites W2008805976 @default.
- W2023863963 cites W2018170658 @default.
- W2023863963 cites W2020193281 @default.
- W2023863963 cites W2031407043 @default.
- W2023863963 cites W2038638538 @default.
- W2023863963 cites W2041588812 @default.
- W2023863963 cites W2051207945 @default.
- W2023863963 cites W2054122134 @default.
- W2023863963 cites W2056342672 @default.
- W2023863963 cites W2062597725 @default.
- W2023863963 cites W2065934151 @default.
- W2023863963 cites W2070094204 @default.
- W2023863963 cites W2075468447 @default.
- W2023863963 cites W2079869057 @default.
- W2023863963 cites W2084738737 @default.
- W2023863963 cites W2094480600 @default.
- W2023863963 cites W2099371576 @default.
- W2023863963 cites W2121536019 @default.
- W2023863963 cites W2128605179 @default.
- W2023863963 cites W2129561360 @default.
- W2023863963 cites W2154156545 @default.
- W2023863963 cites W2316479702 @default.
- W2023863963 cites W2335067109 @default.
- W2023863963 cites W2478284316 @default.
- W2023863963 doi "https://doi.org/10.1016/j.apgeochem.2009.03.004" @default.
- W2023863963 hasPublicationYear "2009" @default.
- W2023863963 type Work @default.
- W2023863963 sameAs 2023863963 @default.
- W2023863963 citedByCount "63" @default.
- W2023863963 countsByYear W20238639632012 @default.
- W2023863963 countsByYear W20238639632013 @default.
- W2023863963 countsByYear W20238639632014 @default.
- W2023863963 countsByYear W20238639632015 @default.
- W2023863963 countsByYear W20238639632016 @default.
- W2023863963 countsByYear W20238639632017 @default.
- W2023863963 countsByYear W20238639632018 @default.
- W2023863963 countsByYear W20238639632019 @default.
- W2023863963 countsByYear W20238639632020 @default.
- W2023863963 countsByYear W20238639632021 @default.
- W2023863963 countsByYear W20238639632022 @default.
- W2023863963 countsByYear W20238639632023 @default.
- W2023863963 crossrefType "journal-article" @default.
- W2023863963 hasAuthorship W2023863963A5063976943 @default.
- W2023863963 hasAuthorship W2023863963A5076929971 @default.
- W2023863963 hasAuthorship W2023863963A5085499013 @default.
- W2023863963 hasConcept C114793014 @default.
- W2023863963 hasConcept C127313418 @default.
- W2023863963 hasConcept C137527640 @default.
- W2023863963 hasConcept C150394285 @default.
- W2023863963 hasConcept C17409809 @default.
- W2023863963 hasConcept C178790620 @default.
- W2023863963 hasConcept C179104552 @default.
- W2023863963 hasConcept C185592680 @default.
- W2023863963 hasConcept C187320778 @default.
- W2023863963 hasConcept C199289684 @default.
- W2023863963 hasConcept C2776062231 @default.
- W2023863963 hasConcept C2777787761 @default.
- W2023863963 hasConcept C2780191791 @default.
- W2023863963 hasConcept C55904794 @default.
- W2023863963 hasConcept C76177295 @default.
- W2023863963 hasConceptScore W2023863963C114793014 @default.
- W2023863963 hasConceptScore W2023863963C127313418 @default.
- W2023863963 hasConceptScore W2023863963C137527640 @default.
- W2023863963 hasConceptScore W2023863963C150394285 @default.
- W2023863963 hasConceptScore W2023863963C17409809 @default.
- W2023863963 hasConceptScore W2023863963C178790620 @default.
- W2023863963 hasConceptScore W2023863963C179104552 @default.
- W2023863963 hasConceptScore W2023863963C185592680 @default.
- W2023863963 hasConceptScore W2023863963C187320778 @default.
- W2023863963 hasConceptScore W2023863963C199289684 @default.
- W2023863963 hasConceptScore W2023863963C2776062231 @default.
- W2023863963 hasConceptScore W2023863963C2777787761 @default.
- W2023863963 hasConceptScore W2023863963C2780191791 @default.
- W2023863963 hasConceptScore W2023863963C55904794 @default.
- W2023863963 hasConceptScore W2023863963C76177295 @default.
- W2023863963 hasIssue "5" @default.
- W2023863963 hasLocation W20238639631 @default.
- W2023863963 hasOpenAccess W2023863963 @default.
- W2023863963 hasPrimaryLocation W20238639631 @default.