The Experts below are selected from a list of 123 Experts worldwide ranked by ideXlab platform
C De Ignacio - One of the best experts on this subject based on the ideXlab platform.
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low temperature shallow water Hydrothermal vent mineralization following the recent submarine eruption of tagoro volcano el hierro canary islands
Marine Geology, 2020Co-Authors: Francisco Javier Gonzalez, Blanca Rincontomas, Luis Somoza, Esther Santofimia, Teresa Medialdea, Pedro Madureira, Enrique Lopezpamo, James R Hein, Egidio Marino, C De IgnacioAbstract:Abstract Hydrothermal iron (Fe)-rich sediments were recovered from the Tagoro underwater volcano (Central Atlantic) that was built during the 2011–2012 volcanic event. Cruises in 2012 and 2014 enabled the monitoring and sampling of the early-stage establishment of a Hydrothermal system. Degassing vents produced acoustic flares imaged on echo-sounders in June 2012, four months after the eruption. In 2014 during a ROV dive was discovered and sampled a novel Hydrothermal vent system formed by hornito-like structures and chimneys showing active CO2 degassing and anomalous temperatures at 120–89 m water depth, and along the SE flank at 215–185 m water depth associated with secondary cones. Iron- and silica-rich gelatinous Deposits pooled over and between basanite in the hornitos, brecciated lavas, and lapilli. The low-temperature, shallow-water Hydrothermal system was discovered by venting of Fe-rich fluids that produced a seafloor draped by extensive Fe-flocculate Deposits precipitated from the neutrally buoyant plumes located along the oxic/pHotic zone at 50–70 m water depths. The basanite is capped by mm- to cm-thick Hydrothermally derived Fe-oxyhydroxide sediments and contain micro-cracks and degasification vesicles filled by sulfides (mostly pyrite). Mineralogically, the Fe-oxyhydroxide sediments consist of proto-ferrihydrite and ferrihydrite with scarce pyrite at their base. The Fe-rich endmember contains low concentrations of most trace elements in comparison with hydrogenetic ferromanganese Deposits, and the sediments show some dilution of the Fe oxyhydroxide by volcanic ash. The Fe-oxyhydroxide phase with a mean particle size of 3–4 nm, low average La/Fe ratios of the mineralized Deposits from the various sampling sites, and the positive Eu anomalies indicate rapid Deposition of the Fe-oxyhydroxide near the Hydrothermal vents. Electron microprobe studies show the presence of various organomineral structures, mainly twisted stalks and sheaths covered by iron-silica Deposits within the mineralized samples, reflecting microbial iron-oxidation from the Hydrothermal fluids. Sequencing of 16 s rRNA genes also reveals the presence of other microorganisms involved in sulfur and methane cycles. Samples collected from hornito chimneys contain silicified microorganisms coated by Fe-rich precipitates. The rapid silicification may have been indirectly promoted by microorganisms acting as nucleation sites. We suggest that this type of Hydrothermal Deposit might be more frequent than presently reported to occur in submarine volcanoes. On a geological scale, these volcanic eruptions and low-temperature Hydrothermal vents might contribute to increased dissolved metals in seawater, and generate considerable Fe-oxyhydroxide Deposits as identified in older hot-spot seamounts.
Francisco Javier Gonzalez - One of the best experts on this subject based on the ideXlab platform.
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low temperature shallow water Hydrothermal vent mineralization following the recent submarine eruption of tagoro volcano el hierro canary islands
Marine Geology, 2020Co-Authors: Francisco Javier Gonzalez, Blanca Rincontomas, Luis Somoza, Esther Santofimia, Teresa Medialdea, Pedro Madureira, Enrique Lopezpamo, James R Hein, Egidio Marino, C De IgnacioAbstract:Abstract Hydrothermal iron (Fe)-rich sediments were recovered from the Tagoro underwater volcano (Central Atlantic) that was built during the 2011–2012 volcanic event. Cruises in 2012 and 2014 enabled the monitoring and sampling of the early-stage establishment of a Hydrothermal system. Degassing vents produced acoustic flares imaged on echo-sounders in June 2012, four months after the eruption. In 2014 during a ROV dive was discovered and sampled a novel Hydrothermal vent system formed by hornito-like structures and chimneys showing active CO2 degassing and anomalous temperatures at 120–89 m water depth, and along the SE flank at 215–185 m water depth associated with secondary cones. Iron- and silica-rich gelatinous Deposits pooled over and between basanite in the hornitos, brecciated lavas, and lapilli. The low-temperature, shallow-water Hydrothermal system was discovered by venting of Fe-rich fluids that produced a seafloor draped by extensive Fe-flocculate Deposits precipitated from the neutrally buoyant plumes located along the oxic/pHotic zone at 50–70 m water depths. The basanite is capped by mm- to cm-thick Hydrothermally derived Fe-oxyhydroxide sediments and contain micro-cracks and degasification vesicles filled by sulfides (mostly pyrite). Mineralogically, the Fe-oxyhydroxide sediments consist of proto-ferrihydrite and ferrihydrite with scarce pyrite at their base. The Fe-rich endmember contains low concentrations of most trace elements in comparison with hydrogenetic ferromanganese Deposits, and the sediments show some dilution of the Fe oxyhydroxide by volcanic ash. The Fe-oxyhydroxide phase with a mean particle size of 3–4 nm, low average La/Fe ratios of the mineralized Deposits from the various sampling sites, and the positive Eu anomalies indicate rapid Deposition of the Fe-oxyhydroxide near the Hydrothermal vents. Electron microprobe studies show the presence of various organomineral structures, mainly twisted stalks and sheaths covered by iron-silica Deposits within the mineralized samples, reflecting microbial iron-oxidation from the Hydrothermal fluids. Sequencing of 16 s rRNA genes also reveals the presence of other microorganisms involved in sulfur and methane cycles. Samples collected from hornito chimneys contain silicified microorganisms coated by Fe-rich precipitates. The rapid silicification may have been indirectly promoted by microorganisms acting as nucleation sites. We suggest that this type of Hydrothermal Deposit might be more frequent than presently reported to occur in submarine volcanoes. On a geological scale, these volcanic eruptions and low-temperature Hydrothermal vents might contribute to increased dissolved metals in seawater, and generate considerable Fe-oxyhydroxide Deposits as identified in older hot-spot seamounts.
Olivier Gasnault - One of the best experts on this subject based on the ideXlab platform.
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Copper enrichments in the Kimberley formation in Gale crater, Mars: Evidence for a Cu Deposit at the source
Icarus, 2019Co-Authors: Valérie Payré, Cécile Fabre, Violaine Sautter, Agnès Cousin, Nicolas Mangold, Laetitia Le Deit, Olivier Forni, Walter Goetz, Roger Wiens, Olivier GasnaultAbstract:Copper quantification with laser induced breakdown spectroscopy (LIBS) using a univariate calibration model enables the ChemCam instrument onboard the Curiosity rover to measure unusually elevated Cu concentrations in potassic sandstones and Mn-oxide-bearing fracture fills in the Kimberley region of Gale crater, Mars. Mostly, the copper phases occurring in sedimentary bedrock are associated with detrital silicates, including feldspars, pyroxenes and K-phyllosilicates, likely coming from a potassic igneous source near the northern crater rim, while those present in the fractures are likely adsorbed on the surface of manganese oxides. These two different mineralogical associations imply at least two distinct processes: Cu enrichment in bedrock at the source, likely during crystallization of the igneous silicates, and adsorption of Cu on Mn-oxides precipitated from groundwater that encountered oxidizing conditions within fractures in the bedrock. The potassic sediments enriched in copper may be evidence of a porphyry copper Deposit or an impact-induced Hydrothermal Deposit in the source region.
Esther Santofimia - One of the best experts on this subject based on the ideXlab platform.
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low temperature shallow water Hydrothermal vent mineralization following the recent submarine eruption of tagoro volcano el hierro canary islands
Marine Geology, 2020Co-Authors: Francisco Javier Gonzalez, Blanca Rincontomas, Luis Somoza, Esther Santofimia, Teresa Medialdea, Pedro Madureira, Enrique Lopezpamo, James R Hein, Egidio Marino, C De IgnacioAbstract:Abstract Hydrothermal iron (Fe)-rich sediments were recovered from the Tagoro underwater volcano (Central Atlantic) that was built during the 2011–2012 volcanic event. Cruises in 2012 and 2014 enabled the monitoring and sampling of the early-stage establishment of a Hydrothermal system. Degassing vents produced acoustic flares imaged on echo-sounders in June 2012, four months after the eruption. In 2014 during a ROV dive was discovered and sampled a novel Hydrothermal vent system formed by hornito-like structures and chimneys showing active CO2 degassing and anomalous temperatures at 120–89 m water depth, and along the SE flank at 215–185 m water depth associated with secondary cones. Iron- and silica-rich gelatinous Deposits pooled over and between basanite in the hornitos, brecciated lavas, and lapilli. The low-temperature, shallow-water Hydrothermal system was discovered by venting of Fe-rich fluids that produced a seafloor draped by extensive Fe-flocculate Deposits precipitated from the neutrally buoyant plumes located along the oxic/pHotic zone at 50–70 m water depths. The basanite is capped by mm- to cm-thick Hydrothermally derived Fe-oxyhydroxide sediments and contain micro-cracks and degasification vesicles filled by sulfides (mostly pyrite). Mineralogically, the Fe-oxyhydroxide sediments consist of proto-ferrihydrite and ferrihydrite with scarce pyrite at their base. The Fe-rich endmember contains low concentrations of most trace elements in comparison with hydrogenetic ferromanganese Deposits, and the sediments show some dilution of the Fe oxyhydroxide by volcanic ash. The Fe-oxyhydroxide phase with a mean particle size of 3–4 nm, low average La/Fe ratios of the mineralized Deposits from the various sampling sites, and the positive Eu anomalies indicate rapid Deposition of the Fe-oxyhydroxide near the Hydrothermal vents. Electron microprobe studies show the presence of various organomineral structures, mainly twisted stalks and sheaths covered by iron-silica Deposits within the mineralized samples, reflecting microbial iron-oxidation from the Hydrothermal fluids. Sequencing of 16 s rRNA genes also reveals the presence of other microorganisms involved in sulfur and methane cycles. Samples collected from hornito chimneys contain silicified microorganisms coated by Fe-rich precipitates. The rapid silicification may have been indirectly promoted by microorganisms acting as nucleation sites. We suggest that this type of Hydrothermal Deposit might be more frequent than presently reported to occur in submarine volcanoes. On a geological scale, these volcanic eruptions and low-temperature Hydrothermal vents might contribute to increased dissolved metals in seawater, and generate considerable Fe-oxyhydroxide Deposits as identified in older hot-spot seamounts.
Pedro Madureira - One of the best experts on this subject based on the ideXlab platform.
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low temperature shallow water Hydrothermal vent mineralization following the recent submarine eruption of tagoro volcano el hierro canary islands
Marine Geology, 2020Co-Authors: Francisco Javier Gonzalez, Blanca Rincontomas, Luis Somoza, Esther Santofimia, Teresa Medialdea, Pedro Madureira, Enrique Lopezpamo, James R Hein, Egidio Marino, C De IgnacioAbstract:Abstract Hydrothermal iron (Fe)-rich sediments were recovered from the Tagoro underwater volcano (Central Atlantic) that was built during the 2011–2012 volcanic event. Cruises in 2012 and 2014 enabled the monitoring and sampling of the early-stage establishment of a Hydrothermal system. Degassing vents produced acoustic flares imaged on echo-sounders in June 2012, four months after the eruption. In 2014 during a ROV dive was discovered and sampled a novel Hydrothermal vent system formed by hornito-like structures and chimneys showing active CO2 degassing and anomalous temperatures at 120–89 m water depth, and along the SE flank at 215–185 m water depth associated with secondary cones. Iron- and silica-rich gelatinous Deposits pooled over and between basanite in the hornitos, brecciated lavas, and lapilli. The low-temperature, shallow-water Hydrothermal system was discovered by venting of Fe-rich fluids that produced a seafloor draped by extensive Fe-flocculate Deposits precipitated from the neutrally buoyant plumes located along the oxic/pHotic zone at 50–70 m water depths. The basanite is capped by mm- to cm-thick Hydrothermally derived Fe-oxyhydroxide sediments and contain micro-cracks and degasification vesicles filled by sulfides (mostly pyrite). Mineralogically, the Fe-oxyhydroxide sediments consist of proto-ferrihydrite and ferrihydrite with scarce pyrite at their base. The Fe-rich endmember contains low concentrations of most trace elements in comparison with hydrogenetic ferromanganese Deposits, and the sediments show some dilution of the Fe oxyhydroxide by volcanic ash. The Fe-oxyhydroxide phase with a mean particle size of 3–4 nm, low average La/Fe ratios of the mineralized Deposits from the various sampling sites, and the positive Eu anomalies indicate rapid Deposition of the Fe-oxyhydroxide near the Hydrothermal vents. Electron microprobe studies show the presence of various organomineral structures, mainly twisted stalks and sheaths covered by iron-silica Deposits within the mineralized samples, reflecting microbial iron-oxidation from the Hydrothermal fluids. Sequencing of 16 s rRNA genes also reveals the presence of other microorganisms involved in sulfur and methane cycles. Samples collected from hornito chimneys contain silicified microorganisms coated by Fe-rich precipitates. The rapid silicification may have been indirectly promoted by microorganisms acting as nucleation sites. We suggest that this type of Hydrothermal Deposit might be more frequent than presently reported to occur in submarine volcanoes. On a geological scale, these volcanic eruptions and low-temperature Hydrothermal vents might contribute to increased dissolved metals in seawater, and generate considerable Fe-oxyhydroxide Deposits as identified in older hot-spot seamounts.
