Evolution of manganese ore genesis in the earth’s geological history and the role of the biosphere

The formation of manganese rocks and ores occurred during the whole geological history of the Earth. Five metallogenic epochs (Early to Middle Proterozoic, Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, and Meso-Cenozoic) and 7 very important phases (Early, Middle, and Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, Late Mesozoic, and Meso-Cenozoic) can be distinguished. The phases of manganese ore genesis at many stratigraphic levels are closely related to the global climatic and tectonic reconstructions (the breakup of the continent of Gondwana and periods of glaciations and aridization) and biotic events (mass extinction of organisms). Based on carbon isotopic composition in manganese carbonates, participation of oxidized organic carbon is established.     

XANES analysis of the mechanisms of arsenic removal in biological iron and manganese treatment unit

Biological iron and manganese removal utilizing indigenous iron and manganese oxidizing bacteria （IRB hereafter） in groundwater can also be applied to arsenic removal according to our pilot-scale test. The arsenic removal probably occurred through sorption and complexation of arsenic to iron and manganese oxides formed by enzymic action of IRB. We investigated the chemical properties of iron and manganese oxides in IRB floc and the valence state of arsenic sorbed to the floc to clarify the mechanisms of the arsenic [especially As （Ⅲ）] removal. The floc samples were collected from two drinking water plants using IRB （Jyoyo and Yamatokoriyama, Japan）, and our pilot - scale test site where arsenic and iron removal using IRB is under way （Mukoh, Japan）. The Jyoyo and Yamatokoriyama IRB floc samples were subjected to As （Ⅲ） and As（Ⅴ） sorption experiments. The elemental composition of the floc samples was measured. XANES spectra were collected on As, Fe and Mn K-edges at synchrotron radiation facility Spring 8 （Hyogo, Japan）. FT-IR and the X-ray diffraction spectra of the samples were also obtained. The IRB floc contained ca. 35 % Fe, 0.3%-3.5% Mn and 2%-6% P. The samples were highly amorphous and contained ferrihidrites and hydrated iron phosphate. According to XANES analyses of IRB, As associated with IRB was in ＋5 valence state when As （Ⅲ） （or As （Ⅴ）） was added in laboratory sorption test, Fe in ＋3 valence state, and Mn a mixture of＋3 and ＋4 valence states. Small shift was observed in the XANES spectra of IRB on As K-edge as the equilibration time of the sorption experiment was increased. Gradual oxidation of a small amount of As （Ⅲ） associated with IRB or change in arsenic binding with sorption site were the probable mechanism.     

Changes in manganese and lead in the environment and young children associated with the introduction of MMT in gasoline

This is a 4-year longitudinal study to evaluate changes to the environment and exposure of young children associated with the introduction of methylcyclopentadienyl manganese tricarbonyl （MMT） into Australia in 2000. The cohort includes 57 females and 56 males; age range of 0.29 to 3.9 years. Samples are collected every 6 months from children in residences located at varying distances from major traffic thoroughfares in Sydney. Environmental samples： air, house and day care dustfall, soil, dust sweepings and gasoline. Samples from children： blood, urine, handwipes prior to and after playing outdoors, and a 6-day duplicate diet. All samples are analyzed for a suite of 20 elements using ICP-MS. Results are presented for the first three 6-month sampling periods for Pb and Mn. For dustfall accumulation, there was no significant change over the 3 sampling periods （time） for Pb or Mn, and a positive relationship between ‘traffic exposure＇ （traffic volume and proximity to the road） and Pb but not Mn. For handwipes, Pb and Mn in wipes taken from children after playing outdoors were usually significantly greater than for wipes taken prior to playing. There was no significant association between Pb or Mn in handwipes with traffic exposure. Dustfall accumulation was a significant predictor for Pb in the handwipes, and dust sweepings were a significant predictor of Mn in handwipes.     

The iron/manganese occurrences of the Desná Unit NE of the Sobotín Amphibolite Massif,Silesicum, Czech Republic: A reply to the paper of

Our reply deals with the investigations of Kropáč et al. (2012) concerning the evolution of Mn-rich garnetites (=coticules) in the Silesian Desná Unit which are closely associated with Fe-rich rocks. Pouba (1970) who described these mineralizations in greater detail, postulated an origin identical with banded iron-formations of the Algoma type. However, Mücke and Losos (2007) excluded a banded iron-formation origin for the magnetite mineralizations and came to the conclusion that these are connected with the Devonian amphibolite of the Sobotín Massif. The older garnetites were inferred to be identical with coticules and, therefore, are comparable with Mn-rich iron-formations of the Algoma type. Concerning the coticules, Kropáč et al. (2012) confirmed the same origin as proposed by us. For the magnetite-rich rocks, on the other hand, Kropáč et al. (2012) strictly followed Pouba (1970), but did neither present new results or data, nor considered the arguments of Mücke and Losos (2007). In this reply, the most important results of Mücke and Losos (2007) are discussed in comparison with banded iron-formations.     

Refinement of genetic and structural models of the úrkút manganese ore deposit (W-Hungary, Europe) using statistical evaluation of archive data

Although the úrkút manganese ore deposit in western placecountry-regionHungary has been exploited for at least 90 years, there are still numerous open questions concerning ore genetics as well as structure and geometry of the ore body. A large set of available archive data for the deposit have been reviewed and evaluated in order to solve some of the most crucial problems. For processing, besides diverse GIS approaches, univariate and multivariate statistical methods were used on the created unified database. The main aims of the mathematical treatment were giving a classification scheme for the wide spectrum of Mn-ores based on their chemical composition (Mn, Fe, Si, P) as well as evaluation of their spatial distribution. For the ore characterization and understanding the genetic processes, cluster and discriminant function analyses were used. Results of the multivariate treatment verified the existence of different ore types and provided an exact chemical definition for all of them. It alsoinferred that the main geochemical processes that took place in ore genesis were similar for all sample groups (ore types) with significantly different weights in each case. A 3D evaluation of the úrkút mine heading map system shows that the ore body covers the footwall surface as a stratiform sheet throughout the study area. Palaeo-relief studies suggest a significant difference between the footwall and hanging wall morphologies which clearly implies tectonic activity following ore deposition. The deposit was affected by an E-W compression stress field near the Aptian-Albian transition causing folding of the Mn deposit.     

Mössbauer studies of marine and fresh water manganese nodules

Practically identical Mössbauer spectra have been obtained for 40 ferromanganese nodules from a wide variety of marine and fresh-water locations. None of the nodules examined contains more than one weight percent Fe²⁺, so no more than a few percent of the total iron in these nodules can be Fe²⁺. Most of the iron is present as Fe³⁺ in paramagnetic or superparamagnetic oxide phases, although hysteresis loops show the presence of small amounts of ferromagnetic phases not detected by the Mössbauer technique.     

Manganese deposits: Communication 2. Major epochs and phases of manganese accumulation in the Earth’s history

Accumulation of manganiferous rocks in the history of the Earth’s lithosphere evolution began not later than the end of the Middle Archean. Primary manganese sediments were accumulated at that time in shallow-water sedimentation basins with the active participation of organic matter. The concentration of Mn in the primary sediments usually did not reach economic values. The formation of genuine manganese ores is related to later processes of the transformation of primary ores—diagenesis, catagenesis, metamorphism, and retrograde diagenesis. Types of basins of manganese ore sedimentation and character of processes of the formation of manganese sediments during the Earth’s shell evolution changed appreciably and correlated with the general evolution of paleocontinents. Major periods, epochs, and phases of manganese ore genesis are defined. At the early stages of lithosphere formation (Archean-Proterozoic), manganese was deposited in basins commonly confined to the central part of Western Gondwana and western part of Eastern Gondwana, as well as the western part of the Ur paleocontinent. Basins of manganese ore sedimentation were characterized by the ferruginous-siliceous, carbonaceous-clayey, and carbonaceous-carbonate-clayey composition. The Early-Middle Paleozoic epoch of manganiferous sediment accumulation was characterized by the presence of several small sedimentation basins with active manifestation of volcanic and hydrothermal activity. Since the formation of Pangea in the Late Paleozoic until its breakup, accumulation of Mn was closely associated with processes of diagenesis and active participation of the oxidized organic matter.     

Geochemical evidence for a multi-source origin of manganese in the Montaña de Manganeso deposit,central Mexico

The Montaña de Manganeso is a manganese vein-type deposit spatially associated with back-arc basin remnants of the Guerrero tectonostratigraphic terrane. The study of major- and trace-element geochemical characteristics of the deposit provides insight into the controls on ore-forming processes within the area. The deposit is characterized by low Co, Cu and Ni abundances, and high Ba (>10,000 ppm) contents and Mn/Fe ratios (<500), typical of hydrothermal Mn deposits. In addition, the low ∑REE abundances (18.7 to 103 ppm), negative Ce anomalies (0.2 to 0.6), and positive Y (1.00 to 2.34) and Eu anomalies (0.6 to 4.4) also suggest a hydrothermal source for the deposit. Discrimination plots involving ∑REE and Zr vs. (Cu + Ni + Co) and Ce/Ce* vs. Nd and Y/Ho further indicate a hydrothermal source in an oxidizing depositional environment. The Mn-Fe-(Ni + Cu + Co), MnO₂-MgO-Fe₂O₃, (Cu/Zn)/Fe₂O₃ vs. (Zn/Ni)/MnO₂ and Na/Mg diagrams display intermediate signatures between marine and terrestrial environments. This suggest that the Montaña de Manganeso deposit is the result of two metallogenic stages: (I) the earliest stage, which involved the formation of Mn oxides by hydrothermal/diagenetic processes in the Arperos back-arc basin during the Cretaceous; and (II) the latest stage took place subsequent to accretion the Guerrero tectonostratigraphic terrane onto the continent and involved the remobilization of the Cretaceous submarine Mn oxides (and associated trace elements) and subsequent redepositation by Tertiary continental hydrothermal activity.     

Geodynamic and climate controls in the formation of Mio–Pliocene world-class oxidized cobalt and manganese ores in the Katanga province, DR Congo

The Katanga province, Democratic Republic of Congo, hosts world-class cobalt deposits accounting for ~50% of the world reserves. They originated from sediment-hosted stratiform copper and cobalt sulfide deposits within Neoproterozoic metasedimentary rocks. Heterogenite, the main oxidized cobalt mineral, is concentrated as “cobalt caps” along the top of silicified dolomite inselbergs. The supergene cobalt enrichment process is part of a regional process of residual ore formation that also forms world-class “manganese cap” deposits in western Katanga, i.e., the “black earths” that are exploited by both industrial and artisanal mining. Here, we provide constraints on the genesis and the timing of these deposits. Ar–Ar analyses of oxidized Mn ore and in situ U–Pb SIMS measurements of heterogenite yield Mio–Pliocene ages. The Ar–Ar ages suggest a multi-phase process, starting in the Late Miocene (10–5 Ma), when the metal-rich substratum was exposed to the action of meteoric fluids, due to major regional uplift. Further oxidation took place in the Pliocene (3.7–2.3 Ma) and formed most of the observed deposits under humid conditions: Co- and Mn-caps on metal-rich substrata, and coeval Fe laterites on barren areas. These deposits formed prior to the regional shift toward more arid conditions in Central Africa. Arid conditions still prevailed during the Quaternary and resulted in erosion and valley incision, which dismantled the metal-bearing caps and led to ore accumulation in valleys and along foot slopes.     

Influence of pH on properties of Mn–Zn ferrites synthesized from low-grade manganese ore

Acta Geochimica - Mn–Zn ferrite powders were produced from low-grade manganese ore (LMO) via the chemical co-precipitation method combined with the ceramic method, after the LMO was leached...     

Geologic feature, origin of the Tiantang lead-zinc manganese polymetallic ore deposit in Jian＇ou City, Fujian Province

天堂铅锌锰多金属矿地处闽中裂谷带北段、武夷山成矿带东缘,矿体明显受南北向断裂带及其派生的北东东向断裂构造控制。矿区发现铅锌锰多金属矿体3条,均产于北东东向断裂构造破碎带内。在矿体空间分布上分带明显,具有上锰、下铅锌（银）的特点。初步研究认为矿床属中低温热液成因,成矿物质主要来源于马面山群变质基底,深部铅锌（银）多金属矿的找矿潜力较大。     

First Determination of the Isotope Age of the Andesite–Dacite Complex of the Eastern Zone of the Middle Urals

Doklady Earth Sciences - This paper reports on the first U–Pb dating of zircons from dacites of the volcanic paleo-edifice of the andesite–dacite complex of the Eastern Zone of the...     

Geochemical characteristics of selected elements in iron–manganese cutans and matrices of Alfisols in central China

The elemental geochemistry of major, minor and trace elements in iron–manganese cutans and the corresponding matrix soils, collected from three Alfisols in central China, are studied using their chemical compositions as well as correlation and factor analyses. Fe–Mn cutans accumulate high concentrations of MnO₂ and Fe₂O₃. Mean values of these two elements in cutans are about 13.7 and 1.4 times higher than those in the matrix soils. pH, clay contents, extractable X-ray noncrystalline Fe (Feo) and the ratio of Feo to free Fe-oxide (Fed) in cutans are notably higher than those in the corresponding matrices. Cutans are also enriched in some bases and heavy metals. Averages of K, Na, Co and Pb concentrations are about 2.0, 1.4, 15.4 and 6.0 times higher than those in the matrices. Statistical analysis indicates that Co, Ni, Li, Cu and Zn are abundant in Mn minerals of cutans, while Pb exists mainly in iron minerals. Fe–Mn cutans constitute an active microzone of solid–solution–plant–air interaction, element movement and exchange in soils, which cause the contents of Fe- and Mn-oxides, elemental concentrations, and geochemical behavior of cutan to show marked differences in matrix soils.     

Analysis of the degree of contamination and evolution in the last 100 years of the composition of the bed sediments of the Anllóns Basin

In this study, five cores of the Anllóns River bed sediments were analyzed in order to evaluate the downcore and downstream variations in their chemical composition. The first step was the evaluation of the metal distribution in the bulk (<2 mm) and fine fractions (<63 μm). The analysis revealed that most of the metals followed the same trend in both fractions, although the fine fraction presented usually higher concentrations. However, the concentration of both fractions tended to equalize with increasing contamination. No general increase was observed in the metal concentrations toward the surface which could be attributed to recent anthropogenic contributions. Instead, the distributions were homogeneous or peaked at various depths downcore. The most important historical feature was observed at the mouth of the river, at 96-cm depth, corresponding to the end of the eighteenth century. Upcore increased metal concentrations in parallel with increased fine fraction occurred from this depth, which were attributed to a bridge construction and consequent changes in sediment dynamics. As the metal concentrations can be influenced by variations in texture or other sediment characteristics, the second step was to evaluate the efficiency of several normalized indexes in the assessment of the degree of contamination, by calculating the enrichment factor (EF), the geoaccumulation index (I _GEO) and the pollution load index (PLI). The EFs obtained were <10, thus revealing little anthropogenic inputs to the basin. The I _GEO produced higher values when compared with the EFs. Instead of absolute EF or I _GEO absolute values, the use of cumulative probability plots allowed identifying more accurately potential outliers indicating contamination. Only one population was identified for Zn and Pb, with a reduced number of outliers at the highest concentrations for Pb. As shown, a more complex plot with the outliers identified at C4 and C5. Finally, the PLI allowed determining the absence of a significant contamination in the bed sediments. The bioavailable and non-geogenic fractions contribute up to a 90% of the total concentrations in the case of As and Cu, and showed similar (dissimilar) profiles in comparison with total metals. Also, the quality guidelines were surpassed, so the high solubility of As, Zn, Pb and Ni in the sediments revealed the need to monitor the bed sediment quality of the Anllóns River.     

Present-day tectonics of the western part of the Dzhugdzhur–Stanovoi Terrane of the southeastern frame of the North Asian Craton

The first results on current movements are presented for the western part of the Dzhugdzhur–Stanovoi Terrane based on GPS geodesy of a geodynamic survey area of the Upper Amur region. Processing of the GPS data resulted in a vector field of the displacement rates of points of the geodynamic survey area with zones of intense deformations. It was concluded from a comprehensive analysis of geological–geophysical data and estimates of the displacement rates that the terrane is characterized by kinematic integrity and was subjected to a complex of tectonic factors related to the evolution of the eastern segment of Baikal Rift Zone in the area of transpression interaction of the Eurasian and Amur plates.     

Bursting the limits of time： the reconstruction of geohistory in the age of revolution

Bursting the Limits of Time by the distin- guished historian of geology Martin Rudwick is a massive, two-part book. The first part contains what he calls a synchronous history of what eventually became historical geology in western Europe between the time of de Sans- sure＇s epoch-making ascent of Mont Blanc in 1787 and the discovery of the Kirkdale hyaena cave by Buckland in the winter of 1821-1822,     

The metallogenic environment of the Dounan manganese deposit,Southeast Yunnan,China: evidence from geochemistry and Mössbauer spectroscopic

Acta Geochimica - The Dounan manganese deposit is a typical large-scale marine sedimentary manganese deposit of the Middle Triassic in China. The metallogenic environment and change process...     

Features of the Influence of Weather Conditions on the Deformation Processes of the Upper Layer of the Earth’s Crust

Doklady Earth Sciences - The influence of the temperature and moisture content of the near-surface soil layer on variations of the barodeformation interaction of the boundary layer of the...     

Numerical Modeling of the Effects of Major Elements on the Solubility of Chrome–Spinel and a Likely Solution of the Problem of the Origin of Chromitite

Doklady Earth Sciences - The influence of variations in fo-, fa-, en-, fs-, di-, an-, and ab-components in a high-Mg basaltic melt on the topology of the spinellide liquidus was analyzed using the...