Hydrothermal iron (Fe)-rich sediments were recovered from the Tagoro underwater volcano (Central Atlantic) that formed 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. A novel hydrothermal vent system was discovered and sampled in 2014 during a ROV dive. The system is characterized 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 the 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 sediment, and contains micro-cracks and degasification vesicles filled by sulfides (mostly pyrite). Mineralogically, the Fe-oxyhydroxide sediment consists 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.

从2011-2012年火山事件形成的塔戈罗水下火山（中大西洋）中回收了富含铁液的热液。2012年和2014年的巡游启用了对水热系统早期建立的监控和采样。喷发四个月后，2012年6月，排气孔产生了回声，并在回声探测器上成像。ROV潜水期间，2014年发现并采样了一种新型的热液排放系统。该系统的特征是霍尼托状结构和烟囱显示出活性的CO ₂120-89 m水深处的脱气温度和反常温度，以及与次级锥体相关的SE侧面在215-185 m水深处的SE侧面。hornitos的玄武岩，角砾岩熔岩和lapilli之上和之间聚集了富含铁和二氧化硅的凝胶状沉积物。低温，浅水热液系统是通过排泄富铁流体而发现的，富铁流体产生了海底，该海底被大量的铁絮状沉积物覆盖，这些沉积物是从沿水/氧化层位于水深50-70 m的中性浮力羽流中沉淀出来的。玄武岩被热解法产生的毫米至厘米厚的Fe-羟基氧化物沉积物覆盖，并包含微裂纹和充满硫化物（主要是黄铁矿）的脱气小泡。矿物学上，羟基氧化铁沉积物由原铁矿水铁矿和亚铁水铁矿组成，其底部缺乏黄铁矿。与氢锰铁矿床相比，富铁端基中的痕量元素含量低，并且沉积物显示出火山灰对氢氧化铁的某些稀释作用。Fe-羟基氧化铁相的平均粒径为3-4 nm，各个采样点的矿化沉积物的平均La / Fe比较低，且Eu异常正值表明，Fe-羟基氧化铁在热液喷口附近快速沉积。电子探针研究表明，存在多种有机矿物结构，主要是矿物质样品中的铁-硅沉积物覆盖着扭曲的茎杆和鞘，反映了热液中微生物的铁氧化作用。16 s rRNA基因的测序还揭示了参与硫和甲烷循环的其他微生物的存在。从霍尼托烟囱收集的样品包含被富铁沉淀物覆盖的硅化微生物。快速硅化作用可能已被作为成核位点的微生物间接促进。我们建议这种类型的热液沉积物可能比目前报道的在海底火山中发生的频率更高。在地质规模上，这些火山喷发和低温热液喷口可能会导致海水中溶解金属的增加，并产生大量铁氢氧化物沉积，如在较早的热点海山中所发现的那样。我们建议这种类型的热液沉积物可能比目前报道的在海底火山中发生的频率更高。在地质规模上，这些火山喷发和低温热液喷口可能会导致海水中溶解金属的增加，并产生大量铁氢氧化物沉积，如在较早的热点海山中所发现的那样。我们建议，这种类型的热液沉积物可能比目前报道的海底火山更常见。在地质规模上，这些火山喷发和低温热液喷口可能会导致海水中溶解金属的增加，并产生大量铁氢氧化物沉积，如在较早的热点海山中所发现的那样。