Cenozoic history of phosphogenesis recorded in the ferromanganese crusts of central and western Pacific seamounts: Implications for deepwater circulation and phosphorus budgets

Hyeong, Kiseong; Kim, Jonguk; Yoo, Changsik; Moon, Jai-Woon; Seo, Inah

doi:10.1016/j.palaeo.2013.09.012

Cited by 30 publications

(27 citation statements)

References 77 publications

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“…The first phosphatization episode that affected Fe-Mn crusts from the summit of RGR as determined by CFA extracted from the crusts occurred from about 20 to 15 Ma (Figure 12). This is consistent with a large global phosphatization episode at the Oligocene-Early Miocene boundary (between 27 and 21 Ma) that affected seamounts distributed globally [81,109]. This major event was associated with global change in the ocean system, probably a transition from warm water and sluggish circulation to the establishment of cold water and thermohaline overturning circulation [110].…”

Section: History Of Phosphatization Of Fe-mn Crusts On the Summit Of Rgrsupporting

confidence: 78%

Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

et al. 2020

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The Rio Grande Rise (RGR) is a large elevation in the Atlantic Ocean and known to host potential mineral resources of ferromanganese crusts (Fe–Mn), but no investigation into their general characteristics have been made in detail. Here, we investigate the chemical and mineralogical composition, growth rates and ages of initiation, and phosphatization of relatively shallow-water (650–825 m) Fe–Mn crusts dredged from the summit of RGR by using computed tomography, X-ray diffraction, 87Sr/86Sr ratios, U–Th isotopes, and various analytical techniques to determine their chemical composition. Fe–Mn crusts from RGR have two distinct generations. The older one has an estimated age of initiation around 48–55 Ma and was extensively affected by post-depositional processes under suboxic conditions resulting in phosphatization during the Miocene (from 20 to 6.8 Ma). As a result, the older generation shows characteristics of diagenetic Fe–Mn deposits, such as low Fe/Mn ratios (mean 0.52), high Mn, Ni, and Li contents and the presence of a 10 Å phyllomanganate, combined with the highest P content among crusts (up to 7.7 wt %). The younger generation is typical of hydrogenetic crusts formed under oxic conditions, with a mean Fe/Mn ratio of 0.75 and mean Co content of 0.66 wt %, and has the highest mean contents of Bi, Nb, Ni, Te, Rh, Ru, and Pt among crusts formed elsewhere. The regeneration of nutrients from local biological productivity in the water column is the main source of metals to crusts, providing mainly metals that regenerate rapidly in the water column and are made available at relatively shallow water depths (Ni, As, V, and Cd), at the expense of metals of slower regeneration (Si and Cu). Additionally, important contributions of nutrients may derive from various water masses, especially the South Atlantic Mode Water and Antarctic Intermediate Water (AAIW). Bulk Fe–Mn crusts from the summit of RGR plateau are generally depleted in metals considered of greatest economic interest in crusts like Co, REE, Mo, Te, and Zr, but are the most enriched in the critical metals Ni and Li compared to other crusts. Further investigations are warranted on Fe–Mn crusts from deeper-water depths along the RGR plateau and surrounding areas, which would less likely be affected by phosphatization.

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Section: History Of Phosphatization Of Fe-mn Crusts On the Summit Of Rgrsupporting

confidence: 78%

Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

et al. 2020

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“…High-resolution analyses also evidence abundant coccoliths and the dispersal of filament structures related to the microbial activity ( Figure 6E), similar to those described in other Fe-Mn crusts and nodules [81][82][83]. Fe-oxyhydroxide (e.g., [75][76][77][78][79]). This process can strongly modify the crust mineralogy by increasing their Mn/Fe ratio [10,79], as observed in DR07-8 crust reaching Mn/Fe ratios up to 1.03.…”

Section: Genesis Of Fe-mn Crusts Based On High-resolution Analysessupporting

confidence: 73%

“…Additionally, the growth of authigenic CFA related to pervasive phosphatization of crust DR07-8 is evidenced by their higher contents of P 2 O 5 (3.7 wt %) and CaO (8.2 wt %) ( Figure 4), and this is reflected in XRD experiments ( Figure 5A) and petrographic observations. Phosphatization in this ferromanganese crust occurs by means of preferential replacement of carbonates and Fe-oxyhydroxide (e.g., [75][76][77][78][79]). This process can strongly modify the crust mineralogy by increasing their Mn/Fe ratio [10,79], as observed in DR07-8 crust reaching Mn/Fe ratios up to 1.03.…”

Section: Genesis Of Fe-mn Crusts Based On High-resolution Analysesmentioning

confidence: 99%

“…This fraction also concentrates significant amounts of Al (1.14 and 0.33 wt %), Ti (0.44 and 0.32 wt %), and P (0.4 and 0.2 wt %). The concentration of these elements is associated with the presence of iron detrital minerals or generated by an early phosphatization event in DR07-8 crust (e.g., [75][76][77][78][79]). Detrital or volcaniclastic minerals represented by minor contents of titano-magnetite, pyroxene or amphibole, and authigenic CFA partially dissolved in this leaching step are commonly associated with the presence of Fe [6,15,69].…”

Section: Major Elements Defining the Main Mineral Phasesmentioning

confidence: 99%

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High-Resolution Analysis of Critical Minerals and Elements in Fe–Mn Crusts from the Canary Island Seamount Province (Atlantic Ocean)

et al. 2018

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Two Fe–Mn crusts among 35 samples, from six seamounts in the Canary Island Seamount Province, were selected as representatives of the endpoint members of two distinct types of genetic processes, i.e., mixed diagenetic/hydrogenetic and purely hydrogenetic. High-resolution analyses pursued the main aim of distinguishing the critical elements and their association with mineral phases and genetic processes forming a long-lived Fe–Mn crust. The Fe–Mn crust collected on the Tropic Seamount is composed of dense laminations of Fe-vernadite (>90%) and goethite group minerals, reflecting the predominance of the hydrogenetic process during their formation. Based on high-resolution age calculation, this purely hydrogenetic crust yielded an age of 99 Ma. The Fe–Mn crust collected on the Paps Seamount shows a typical botryoidal surface yielding an age of 30 Ma. electron probe microanalyzer (EPMA) spot analyses show two main types of manganese oxides, indicating their origin: (i) hydrogenetic Fe-vernadite, the main Mn oxide, and (ii) laminations of interlayered buserite and asbolane. Additionally, the occurrence of calcite, authigenic carbonate fluor-apatite (CFA) and palygorskite suggests early diagenesis and pervasive phosphatization events. Sequential leaching analysis indicated that Co, Ni, Cu, Ba and Ce are linked to Mn minerals. Therefore, Mn-oxides are enriched in Ni and Cu by diagenetic processes or in Co and Ce by hydrogenetic processes. On the other hand, Fe-oxides concentrate V, Zn, As and Pb. Moreover, the evidence of HREE enrichment related to Fe-hydroxides is confirmed in the mixed hydrogenetic/diagenetic crust.

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“…Recent age determinations for the boundary between Layers 2 and 3 of Pacific Fe-Mn crusts (Hyeong et al, 2013) lead us to consider that the growth of the Layer 2 of crusts begins earlier on seamounts at higher latitudes rather than at lower latitudes. Such systematic latitudinal time migration on Layer 2 formation should be caused by earlier secession from the region of phosphatization by northwestward movement of the Pacific plate.…”

Section: Constraints On Formation Age Of Nodulesmentioning

confidence: 99%

Geology and geochemistry of ferromanganese nodules in the Japanese Exclusive Economic Zone around Minamitorishima Island

et al. 2016

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moteness is an obstacle to mining operations. However, large Fe-Mn nodules have also been found to be densely distributed on a seamount in the eastern part of the Japanese Exclusive Economic Zone (EEZ) around Minamitorishima (Marcus) Island, Japan, where their resource potential is more promising because they are located closer to the main islands of Japan than the CCZ. Thus, further exploration in the EEZ can be expected, along with future development followed by the self-sufficiency and the stabilization of the market for critical metals. In this report, we describe results of a geological survey using the submersible SHINKAI 6500 and a multiple narrow-beam echo sounder system during cruise YK10-05 of R/V Yokosuka. We also present the results of chemical analyses to define geochemical features for representative Fe-Mn nodules and adjacent Fe-Mn crusts.

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Cenozoic history of phosphogenesis recorded in the ferromanganese crusts of central and western Pacific seamounts: Implications for deepwater circulation and phosphorus budgets

Cited by 30 publications

References 77 publications

Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

High-Resolution Analysis of Critical Minerals and Elements in Fe–Mn Crusts from the Canary Island Seamount Province (Atlantic Ocean)

Geology and geochemistry of ferromanganese nodules in the Japanese Exclusive Economic Zone around Minamitorishima Island

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