Deposition of submarine crusts rich in manganese and iron

Toth, John R.

doi:10.1130/0016-7606(1980)91<44:doscri>2.0.co;2

Cited by 308 publications

(157 citation statements)

References 0 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…In a ternary Al-Fe-Mn diagram (Dymond and Corliss, 1973;Toth, 1980), all reference samples are almost Mn-free with an Al/Fe mass ratio of about 1.32 (Fig. 7).…”

Section: Chemical Data 421 Major and Trace Elementsmentioning

confidence: 99%

Characterization of metalliferous sediment from a low-temperature hydrothermal environment on the Eastern Flank of the East Pacific Rise

et al. 2008

View full text Add to dashboard Cite

Metalliferous deposits are described from the eastern flank of the East Pacific Rise (EPR) offshore Costa Rica, close to a basaltic seamount called "Dorado high".Based on heat-flow data and porewater profiles, the site is an area of active low temperature hydrothermal discharge. We focus on the mineralogical and chemical analyses from a 124 cm long gravity core (GC50), located on the north-western slope of the 100 m high Dorado high. In this core, the sediments consist of detrital clay minerals as well as authigenic minerals such as zeolites, apatites, and Fe/Mn-rich oxyhydroxides. In contrast, the reference sediments from adjacent areas without hydrothermal activity are olive gray hemipelagic muds composed of volcanic glass particles, clay minerals, siliceous microfossils, and some detrital quartz and feldspar.Bulk sediment chemistry and chemical enrichment factors calculated with respect to the reference sediment indicate that the most important chemical changes occurred at the base of the core from 100 to 124 cm bsf, with strong enrichments in MnO, CaO, P 2 O 5 , and Fe 2 O 3 . These enrichments are correlated with the occurrence of authigenic Fe-oxyhydroxide (goethite) and Mn oxide (todorokite and vernadite, at 100 cm bsf), and hydrothermal apatite (110-124 cm bsf). In the upper section of the core from 12 to 70 cm, the sediment is composed of abundant smectite and authigenic phillipsite, and only minor chemical changes can be observed with respect to the reference sediments.The ubiquitous presence of phillipsite suggests that the entire sedimentary column of core GC50 was first affected by diagenesis. However, below 70 cm bsf, these phillipsites are partially dissolved and Fe oxides occur from 110 to 124 cm, followed 2 upward by Mn oxides at 100 cm. This transition from Fe to Mn rich sediments can be interpreted in terms of an upward increasing redox potential. PAAS-normalized REE patterns of GC50 sediments present clearly negative Ce and positive Y anomalies inherited from seawater at the base of core GC50. These anomalies decrease upward, which we interpret together with the transition from Fe to Mn-rich sediments by an upward migrating low temperature hydrothermal fluid. Thus, after a first stage of diagenesis, the discharge of a low temperature hydrothermal fluid occurred through the sedimentary column, leading to the precipitation of hydrothermal compounds that are lacking towards the surface.

show abstract

“…In a ternary Al-Fe-Mn diagram (Dymond and Corliss, 1973;Toth, 1980), all reference samples are almost Mn-free with an Al/Fe mass ratio of about 1.32 (Fig. 7).…”

Section: Chemical Data 421 Major and Trace Elementsmentioning

confidence: 99%

Characterization of metalliferous sediment from a low-temperature hydrothermal environment on the Eastern Flank of the East Pacific Rise

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Modern studies of metalliferous sediments from the ocean basins indicate that the common iron and manganese compounds that occur as nodules or crusts on active spreading centers and seamounts consist of poorly crystallized oxides and hydroxide phases. These may be manganites, birnessite, todorokite, and rhodochrosite in the Mn-rich crust (Bonatti et al 1976), or goethite and nontronite in iron-rich crusts (Toth 1980). Lithology, textural features, and form of the orebodies are consistent with a synsedimentary formation within an intra-arc basin (Pincheira and Thiele 1982).…”

Section: Discussionmentioning

confidence: 75%

“…Groutite, MnO(OH), produced also bixbyite and hausmannite at comparable temperatures. The lack of braunite, jacobsite, and hausmannite in modern nodules and metalliferous sediments from ocean basins and shallow seas (e.g., Barents Sea, Gulf of Maine, Kara Sea; Roy 1981) suggests that the natural conditions on the sea floor are not favorable to the formation of these minerals in sedimentary environments (Sorem and Gunn 1967;Bonatti et al 1976;Rona 1978;Toth 1980). Modern studies of metalliferous sediments from the ocean basins indicate that the common iron and manganese compounds that occur as nodules or crusts on active spreading centers and seamounts consist of poorly crystallized oxides and hydroxide phases.…”

Section: Discussionmentioning

confidence: 99%

La Negra-Coquimbana Manganiferous District, Southern Atacama Desert, Chile

Pincheira

Fontboté

1990

Stratabound Ore Deposits in the Andes

View full text Add to dashboard Cite

“…High Co/Zn values in most samples, however, are more typical for hydrogenic deposits (Toth, 1980): Co/Zn is typically > 2.5 in hydrogenic Mn-Fe nodules, and in Nangodi manganese rocks ranges from 0.24-11. Melcher and Stumpfl (1992, 1993) assume a significant hydrothermal component in the manganese rocks, which is mixed with varying proportions of volcanogenic, and very probably hydrogenic components also.…”

Section: Geochemistry Of Manganese-bearing Rocksmentioning

confidence: 99%

Genesis of chemical sediments in Birimian greenstone belts: evidence from gondites and related manganese-bearing rocks from Northern Ghana

Melcher¹

1995

Mineral. mag.

View full text Add to dashboard Cite

Early Proterozoic chemical sediments of the Birimian Supergroup in northern Ghana host several types of metamorphosed manganese-bearing rocks. Differences in the mineralogy and geochemistry can be attributed to facies changes in a mixed volcanic-volcaniclastic depositional environment. Manganese oxide-bearing phyllite, which is enriched in transition metals (Cu, Ni, Co, Zn), formed on the flanks of submarine volcanic edifices above an oxidation boundary. Towards the deeper basin, manganese silicate-rich gondites occur. These consist either of spessartine + quartz + ilmenite, or of spessartine + quartz + Mn amphiboles __+ rhodonite __+ hyalophane __+ Mn stilpnomelane -t-ilmenite. The Mn amphiboles are identified as manganoan actinolite, tirodite, and dannemorite. Sulphides are widespread as premetamorphic inclusions in Mn garnet grains. In the basin centre, chlorite schist containing garnet with 50-60 mol.% spessartine represents the most distal manganese-bearing rock which is highly diluted by volcanogenic background sedimentation. The origin of Mn-rich rocks is explained by heat-driven seawater convection systems active in submarine volcanic centres that provided hydrothermal solutions. Precipitation of different minerals depended on the geochemical conditions prevailing on the seafloor. During the Eburnean event (around 2000 Ma), the chemical sediments were metamorphosed to upper greenschist or lower amphibolite facies. Mineral assemblages in the gondites point to metamorphic conditions in the range of 450-500~ at 2-3 kbar.

show abstract

Deposition of submarine crusts rich in manganese and iron

Cited by 308 publications

References 0 publications

Characterization of metalliferous sediment from a low-temperature hydrothermal environment on the Eastern Flank of the East Pacific Rise

Characterization of metalliferous sediment from a low-temperature hydrothermal environment on the Eastern Flank of the East Pacific Rise

La Negra-Coquimbana Manganiferous District, Southern Atacama Desert, Chile

Genesis of chemical sediments in Birimian greenstone belts: evidence from gondites and related manganese-bearing rocks from Northern Ghana

Contact Info

Product

Resources

About