Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands
This study presents major and trace elements and uranium (U), lithium (Li) and magnesium (Mg) isotope data for dissolved and suspended particulate material from estuaries draining dominantly basaltic terrains in Iceland (Borgarfjör{eth}ur) and Sao Miguel (Povoação) in the Azores archipelago. The con...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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2008
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| _version_ | 1797103607219224576 |
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| author | Pogge von Strandmann, P James, R van Calsteren, P Gislason, SR Burton, K |
| author_facet | Pogge von Strandmann, P James, R van Calsteren, P Gislason, SR Burton, K |
| author_sort | Pogge von Strandmann, P |
| collection | OXFORD |
| description | This study presents major and trace elements and uranium (U), lithium (Li) and magnesium (Mg) isotope data for dissolved and suspended particulate material from estuaries draining dominantly basaltic terrains in Iceland (Borgarfjör{eth}ur) and Sao Miguel (Povoação) in the Azores archipelago. The concentrations of dissolved sodium (Na), calcium (Ca), potassium (K), sulphate (SO 4), Mg and Li, and 7Li/ 6Li and 26Mg/ 24Mg isotope ratios vary directly as a function of the dissolved chloride concentration [Cl], indicating that these species are non-reactive in these estuaries. However, U appears to be affected either by colloid flocculation or the formation of Fe-oxyhydroxides in Borgarfjör{eth}ur. The major element composition of suspended particulate material in the estuary at Borgarfjör{eth}ur shows that the detrital silicates delivered to the estuarine mixing zone are relatively unweathered. Accordingly, the δ 26Mg isotope composition of the suspended material is indistinguishable from that of the parent basalts. However, the ( 234U/ 238U) activity ratios of the suspended material are significantly different from the parent basalt indicating rapid equilibration of the U isotopes between particles and seawater. The Li concentration and δ 7Li isotope composition of the suspended load are also observed to increase with increasing [Cl], consistent with ongoing weathering of detrital material and the formation of secondary minerals in seawater. Depending on the particle residence time in the estuary, this process could remove as much as 15-25% of the global riverine input of Li to the ocean. © 2008 Elsevier B.V. All rights reserved. |
| first_indexed | 2024-03-07T06:22:28Z |
| format | Journal article |
| id | oxford-uuid:f32772c2-9dd5-456c-b625-6c685b2b8dc6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:22:28Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:f32772c2-9dd5-456c-b625-6c685b2b8dc62022-03-27T12:09:46ZLithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islandsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f32772c2-9dd5-456c-b625-6c685b2b8dc6EnglishSymplectic Elements at Oxford2008Pogge von Strandmann, PJames, Rvan Calsteren, PGislason, SRBurton, KThis study presents major and trace elements and uranium (U), lithium (Li) and magnesium (Mg) isotope data for dissolved and suspended particulate material from estuaries draining dominantly basaltic terrains in Iceland (Borgarfjör{eth}ur) and Sao Miguel (Povoação) in the Azores archipelago. The concentrations of dissolved sodium (Na), calcium (Ca), potassium (K), sulphate (SO 4), Mg and Li, and 7Li/ 6Li and 26Mg/ 24Mg isotope ratios vary directly as a function of the dissolved chloride concentration [Cl], indicating that these species are non-reactive in these estuaries. However, U appears to be affected either by colloid flocculation or the formation of Fe-oxyhydroxides in Borgarfjör{eth}ur. The major element composition of suspended particulate material in the estuary at Borgarfjör{eth}ur shows that the detrital silicates delivered to the estuarine mixing zone are relatively unweathered. Accordingly, the δ 26Mg isotope composition of the suspended material is indistinguishable from that of the parent basalts. However, the ( 234U/ 238U) activity ratios of the suspended material are significantly different from the parent basalt indicating rapid equilibration of the U isotopes between particles and seawater. The Li concentration and δ 7Li isotope composition of the suspended load are also observed to increase with increasing [Cl], consistent with ongoing weathering of detrital material and the formation of secondary minerals in seawater. Depending on the particle residence time in the estuary, this process could remove as much as 15-25% of the global riverine input of Li to the ocean. © 2008 Elsevier B.V. All rights reserved. |
| spellingShingle | Pogge von Strandmann, P James, R van Calsteren, P Gislason, SR Burton, K Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| title | Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| title_full | Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| title_fullStr | Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| title_full_unstemmed | Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| title_short | Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| title_sort | lithium magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands |
| work_keys_str_mv | AT poggevonstrandmannp lithiummagnesiumanduraniumisotopebehaviourintheestuarineenvironmentofbasalticislands AT jamesr lithiummagnesiumanduraniumisotopebehaviourintheestuarineenvironmentofbasalticislands AT vancalsterenp lithiummagnesiumanduraniumisotopebehaviourintheestuarineenvironmentofbasalticislands AT gislasonsr lithiummagnesiumanduraniumisotopebehaviourintheestuarineenvironmentofbasalticislands AT burtonk lithiummagnesiumanduraniumisotopebehaviourintheestuarineenvironmentofbasalticislands |