Cobalt-Rich Ferromanganese Crusts in the Pacific

Hein, James R.; Koschinsk, Andrea; Bau, Michael; Manheim, Frank T.; Kang, Jin‐Kyu; Roberts, Leanne

doi:10.1201/9780203752760-9

Cited by 105 publications

(245 citation statements)

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“…The results strongly indicate that the process of Fe-Mn oxyhydroxide precipitation on the surface of hard rocks in the Pacific Ocean is most unlikely mediated by catalytic processes through bacteria, as suggested by Hein et al (2000) and Wang and Miller (2009). Cui et al (2008) proposed that the microstrata change of light and dark colors of laminae in the columnar structure of cobalt-rich crusts, and the corresponding difference in chemical composition resulted from changes in the micro-redox environment.…”

Section: Fluorescencementioning

confidence: 67%

“…The hydrogenous crust tends to exhibit a more consistent Fe/Mn ratio (about 0.72 for the Pacific Fe-Mn crust) (Hein et al, 1997), and the hydrothermal crust shows a wide range of Fe/Mn ratios (about <0.002 to 3930 for TAG hydrothermal field) (Mills et al, 2001). The Fe/Mn ratio of Fe-Mn crusts in the study area ranges from 1.14 to 1.56, which is close to the composition of Fe-Mn crusts of hydrogenous origin from the Marshall Islands and the far South Pacific (Hein et al, 2000;Mills et al, 2001). The rates of Co, Ni, and Cu are different in the crusts of various origins.…”

Section: Chemical Composition 461 Major and Trace Elementsmentioning

confidence: 80%

“…In addition, other authors later identified five episodes of phosphatization, two of which occurred in the period from Late Cretaceous to early Paleocene and the other three occurred in the latest Eocene-early Oligocene. The growth of the younger crust generation started in the Miocene and has continued to the present, without interruption by further phosphogenic events (Hein et al, 2000). Crusts record not only changes in the chemical composition of ancient surface and intermediate water masses, but also changes in current regimes (Oda et al, 2011;González et al, 2012).…”

Section: Introductionmentioning

confidence: 97%

“…Therefore, the elemental composition of the crusts reflects the composition of seawater rather than pelagic sediments (Quinby-Hunt and Turekian, 1983). Hydrogenetic Fe-Mn crusts grow slowly at rates of approximately 0.55 to 10 mm Myr −1 (Bogdanov et al, 1995;Hein et al, 2000). The age of some crusts has been estimated at 70 Ma, and oth-* Corresponding author.…”

Section: Introductionmentioning

confidence: 98%

“…Iron-manganese oxyhydroxide crusts, hereafter abbreviated as Fe-Mn crusts, form on the top of seamounts on oceanic ridges and plateaus, and are widespread from 52˚N to 47˚S in the Pacific Ocean and between 48˚-63˚S and 90˚E-30˚W in the subantarctic zone (Bogdanov et al, 1995;Blanckenburg et al, 1996;Hein et al, 2000;Rehkämper et al, 2002). Fe-Mn crusts are found in water between 400 and 4000 m depth and to be the thickest between 800 and 2,500 m depth (Bogdanov et al, 1995;Wen et al, 1997;Hein et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

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Composition and origin of ferromanganese crusts from equatorial western Pacific seamounts

Wang

Jansa

Chu

et al. 2015

J. Ocean Univ. China

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In the equatorial western Pacific, iron-manganese oxyhydroxide crusts (Fe-Mn crusts) and nodules form on basaltic seamounts and on the top of drowned carbonate platform guyots that have been swept free of pelagic sediments. To date, the Fe-Mn crusts have been considered to be almost exclusively of abiotic origin. However, it has recently been suggested that these crusts may be a result of biomineralization. Although the Fe-Mn crust textures in the equatorial western Pacific are similar to those constructed by bacteria and algae, and biomarkers also document the existence of bacteria and algae dispersed within the Fe-Mn crusts, the precipitation, accumulation and distribution of elements, such as Fe, Mn, Ni and Co in Fe-Mn crusts are not controlled by microbial activity. Bacteria and algae are only physically incorporated into the crusts when dead plankton settle on the ocean floor and are trapped on the crust surface. Geochemical evidence suggests a hydrogenous origin of Fe-Mn crusts in the equatorial western Pacific, thus verifying a process for Fe-Mn crusts that involves the precipitation of colloidal phases from seawater followed by extensive scavenging of dissolved trace metals into the mineral phase during crust formation.

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Section: Fluorescencementioning

confidence: 67%

Section: Chemical Composition 461 Major and Trace Elementsmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Composition and origin of ferromanganese crusts from equatorial western Pacific seamounts

Wang

Jansa

Chu

et al. 2015

J. Ocean Univ. China

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Phosphorites, Co‐rich Mn nodules, and Fe‐Mn crusts from Galicia Bank, NE Atlantic: Reflections of Cenozoic tectonics and paleoceanography

González

Somoza

Hein

et al. 2016

Geochem Geophys Geosyst

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A wide variety of marine mineral deposits were recovered from 750 to 1400 m water depths on Galicia Bank, Iberian margin. Mineral deposits include: (1) carbonate fluorapatite phosphorite slabs and nodules that replaced limestone and preserved original protolith fabric. (2) Ferromanganese vernadite crusts with high Mn and Fe (Mn/Fe = 1) contents, and thick stratabound layers consisting mainly of Mn (up to 27% MnO) and Fe (15% Fe2O3), which impregnated and replaced the phosphorite. (3) Co‐rich Mn nodules are composed of romanechite and todorokite laminae. Mn‐rich layers (up to 58% MnO) contain up to 1.8% Co. (4) Goethite nodules with Fe up to 67% Fe2O3 have low Mn and trace metals. We interpret this mineralization paragenesis to be related to major changes in oceanographic and tectonic regimes. Three phosphatization generations formed hardgrounds dated by 87Sr/86Sr isotopes as late Oligocene, early Miocene, and latest early Miocene. During the latest early Miocene, the hardground was fractured and breached due to regional intraplate tectonism, which was coeval with a widespread regional erosional unconformity. The stratabound layers and Co‐rich manganese nodules were derived from low‐temperature geothermally driven hydrothermal fluids, with fluid conduits along reactivated faults. During middle and late Miocene, the introduction of vigorous deep water flow from the Arctic generated growth of hydrogenetic ferromanganese crusts. Finally, growth of diagenetic Fe‐rich nodules (late Pliocene) was promoted by the introduction of hypersaline Mediterranean Outflow Water into the Atlantic Ocean.

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The potential of sedimentary foraminiferal rare earth element patterns to trace water masses in the past

Osborne

Hathorne

Schijf

et al. 2017

Geochem Geophys Geosyst

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Dissolved rare earth element (REE) concentration data from intermediate and deep seawater form an array characterized by higher middle‐REE enrichments (MREE/MREE*) in the North Atlantic and a progressive increase in heavy‐to‐light REE ratios (HREE/LREE) as water masses age. The REEs in foraminifera are fractionated toward higher MREE/MREE* and lower HREE/LREE relative to seawater. Calculations based on a scavenging model show that the REE patterns in uncleaned core‐top foraminifera resemble those adsorbed onto calcite, particulate organic material, and hydrous ferric oxides but the full extent of the REE fractionation measured in foraminifera was not reproduced by the model. However, differences in the HREE/LREE and MREE/MREE* ratios and the cerium anomaly between ocean basins are preserved and are in agreement with the seawater REE distribution. Under oxic conditions, the HREE/LREE and MREE/MREE* compositions of uncleaned foraminifera at the sediment/seawater boundary are preserved during burial but the cerium anomaly is sensitive to burial depth. In suboxic sedimentary environments, all uncleaned foraminiferal REE concentrations are elevated relative to core‐top values indicating addition of REEs from pore waters. The HREE/LREE ratio is highest when sedimentation rates were greatest and when high Fe/Ca ratios in the uncleaned foraminifera indicate that Fe was mobile. In sediments that have not experienced suboxic conditions during burial, uncleaned foraminifera preserve the seawater signal taken up at the sediment/seawater interface and are therefore suggested to be a suitable archive of changes in the REE signal of past bottom waters.

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Cobalt-Rich Ferromanganese Crusts in the Pacific

Cited by 105 publications

References 1 publication

Composition and origin of ferromanganese crusts from equatorial western Pacific seamounts

Composition and origin of ferromanganese crusts from equatorial western Pacific seamounts

Phosphorites, Co‐rich Mn nodules, and Fe‐Mn crusts from Galicia Bank, NE Atlantic: Reflections of Cenozoic tectonics and paleoceanography

The potential of sedimentary foraminiferal rare earth element patterns to trace water masses in the past

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