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The world has moved into an era of hidden ore body exploration, necessitating the development of new prospecting and exploration methods. One promising approach is to use the deep convolutional neural network (DCNN) algorithm to extract spatial and correlation characteristics of multiple two-dimensional elements related to hidden ores. This paper explores this method on Datangpo manganese (Mn), constructing prediction datasets that includes geological, geochemical, geophysical and aeromagnetic features. Analyzing metallogenic conditions and control factors of Mn ores, we construct a Mn ore prediction model (Geo-DCNN) based on multiple geographical knowledge and DCNN. The Geo-DCNN model reaches ore-bearing accuracy of 79.11%, non-ore-bearing accuracy of 99.01%, overall accuracy of 95.35%, and loss value of 0.0227 after training. Based on analysis of ROC curve, P-R curve, field investigation, and target area verification, we discover that the prediction results of the Geo-DCNN model in northeast Guizhou have a high correspondence rate with known manganese deposits. This provides valuable insight for further ore exploration in the area. Additionally, the results indicate that the Geo-DCNN model is robust and portable, suggesting that it can be applied to metallogenic prediction practices for manganese ore in similar regions. [ABSTRACT FROM AUTHOR]

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Bryophyte communities have been widely used to monitor and assess heavy metal pollution in soil, air and water. However, the unique value of acrocarpous moss in monitoring environmental pollution and the harm of non-metallic sulfur to human health caused by carbonate manganese mining were seldom considered in previous studies. This study investigated the heavy metal and sulfur pollution level by soil and moss sample collection in Changgou manganese ore and its surrounding environment in the Zunyi area, Guizhou Province, China. By means of cluster analysis, diversity analysis, correlation analysis and redundancy analysis, the relationship between dominant moss communities and major pollutants were analyzed. The results showed that there were pollutants such as iron (Fe), manganese (Mn), cadmium (Cd), sulfur (S) and others in the 500 meters buffer zone centered on Changgou manganese ore. The ore sorting area and waste rock accumulation area were considered as the most seriously polluted, followed by the ore outlet area and ore transport line, at last the miners' living area and vegetable planting area were the least polluted. A total of 23 species of moss communities were identified in the Changgou manganese ore area, among which 9 were dominant, including Bryum blindii Bruch & Schimp. (Bry.bli), Weissia planifolia Dix (Wei.pla) — Bry.bli, Bryum caespiticium Hedw. (Bry.cae), Bryum pallescens Schleicher ex Schwägr. (Bry.pal), Didymodon longicostatus X. J. Li et Iwats (Did.lon), Weissia brachycarpa (Nees & Hornsch.) Jur. (Wei.bra), Trichostomum brachydontium Bruch. (Tri.bra), Bryum argenteum Hedw. (Bry.arg) Wei.bra and Bryum algovicum Sendt.ex Műll. Hal. (Bry.alg), all of which are from the acrocarp species. Bry.cae showed a strong tolerance to S, Did.lon to Fe, Bry.pal to Cd and Bry.bli to Mn. There was a significant correlation between the main polluting elements and the dominant bryophyte community (P<0.05), indicating a high biological indicator value. Together, our results can provide the scientific basis for soil pollution monitoring and human health risk assessment in carbonate manganese mining areas. [ABSTRACT FROM AUTHOR]

Datangpo-type manganese ores which originated in the Cryogenian Datangpo Formation, are overlaid and underlaid by Nantuo diamicite and Tiesi'ao silistones, respectively. A thorough understanding of the manganese mineralization process is currently limited by the continued uncertainty regarding the metallogenic redox condition of the Mn-bearing rock series. This study employed statistical analysis of pyrite framboid sizes and iron isotope (δ56Fe) to determine the redox conditions and constrain the mineralization process of Datangpo-type manganese ores in South China, considering the Gaolou in Chongqing, Yanglizhang in Guizhou, and Minle and Zhenxing in Hunan as examples. The results showed that Tiesi'ao siltstones mainly developed relatively larger diameter (7.29–7.68 μm) framboidal pyrites, whereas mudstones in the Datangpo Formation developed relatively smaller diameter (2.63–5.56 μm) framboidal pyrites. Furthermore, manganese ores produce non-framboidal pyrites. In three profiles, framboidal pyrite concentrations were found to be negatively correlated with Mn contents. These characteristics suggested that siltstones, mudstones, and manganese ores were deposited in oxic-anoxic, dysoxic-euxinic, and oxic-dysoxic conditions, respectively. The δ56Fe of whole rocks (δ56Fe WR) exhibited a range from −0.73 ‰ to +0.48 ‰ (average of −0.32 ‰), whereas pyrite (δ56Fe Py) varied from +0.03 ‰ to +0.83 ‰ (average of +0.36 ‰). Furthermore, δ56Fe Py in manganese ore (average = +0.27 ‰) were lighter than those in mudstone (average = +0.49 ‰). The results of this study demonstrated that oxidation deposition played a role in pyrite formation, with manganese ores exhibiting more oxic conditions compared to mudstones. The findings of this study suggested that idiomorphic pyrite formation was similar to that of manganese ore, in which Mn precipitated in the form of manganese (hydro)oxides under oxic seawater, and then converted into rhodochrosite under anoxic sulfidic diagenetic conditions, with the involvement of microbes. This research has the potential to enhance comprehension regarding redox conditions and the regulation of sedimentary manganese ores via redox transformation. • Pyrite framboids were studied to reflect the sedimentary redox conditions. • Manganese ores deposited under more oxic conditions than siltstones and mudstones. • Iron isotopes reveal that the pyrite formation underwent oxidation deposition. • Manganese precipitated as (hydro)oxides from seawater. • The (hydro)oxides converted into rhodochrosite during diagenesis. [ABSTRACT FROM AUTHOR]

Many plants have been widely used in monitoring and assessing heavy metal pollution in soil, air and water. However, few studies have considered the unique value of bryophyte communities in monitoring manganese ore pollution and the diversity characteristics of bryophytes in different natural succession stages. Tongluojing Manganese Mine in Guizhou Province, China, was chosen for identifying bryophytes and statistical analyses. In total 61 species of mosses in 21 genera of 7 families were identified, including 8 dominant species, primarily representing the turf life-form. Following the successive stages from bare rock to woodland, single-species moss communities decreased while multi-species communities increased, with increment of the α diversity index. However, the β diversity index showed the opposite trend. The moss similarity index was the highest (0.43) and Cody index lowest (7.5) on bare rock, while the indices were the lowest (0.17) and the highest (18), respectively, in woodland. The Nemerow pollution index decreased gradually with the successive stages, with the bare rock area being the most polluted. The soil was polluted by Pb, Cr, Zn, Cd and Mn to varying degrees, among which Mn was the biggest pollutant with a concentration 129 times higher than the background value of the soil in Guizhou Province. There was a positive correlation between the contents of Cd, Cr, Zn and Mn in Weissia planifolia Dix and those in the substrate, suggesting that W. planifolia can be used as an indicator plant. This study highlighted multiple effects of mosses on heavy metal absorption, which could be used as pioneer plants for vegetation restoration in the manganese ore waste rock accumulation area. [ABSTRACT FROM AUTHOR]

The Zunyi manganese deposits, which formed during the Middle to Late Permian period and are located in northern Guizhou and adjacent areas, are the core area of a series of large‐medium scale manganese enrichment minerogenesis in the southern margin and interior of the Yangtze platform, Southern China. This study reports the universal enrichment of rare earth elements (REEs) in Zunyi manganese deposits and examines the enrichment characteristics, metallogenic environment and genesis of REEs. The manganese ore bodies present stratiform or stratoid in shape, hosted in the silicon–mud–limestones of the Late Permian Maokou Formation. The manganese ores generally present lamellar, massive, banded and brecciated structures, and mainly consist of rhodochrosite, ropperite, tetalite, capillitite, as well as contains paragenetic gangue minerals including pyrite, chalcopyrite, rutile, barite, tuffaceous clay rock, etc. The manganese ores have higher ΣREE contents range from 158 to 1138.9 ppm (average 509.54 ppm). In addition, the ΣREE contents of tuffaceous clay rock in ore beds vary from 1032.2 to 1824.5 ppm (average 1396.42 ppm). The REEs from manganese deposits are characterized by La, Ce, Nd and Y enriched, and existing in the form of independent minerals (e.g., monazite and xenotime), indicating Zunyi manganese deposits enriched in light rare earth elements (LREE). The Ceanom ratios (average –0.13) and lithofacies and paleogeography characteristics indicate that Zunyi manganese deposits were formed in a weak oxidation‐reduction environment. The (La/Yb)ch, Y/Ho, (La/Nd)N, (Dy/Yb)N, Ce/Ce* and Eu/Eu* values of samples from the Zunyi manganese deposits are 5.53–56.92, 18–39, 1.42–3.15, 0.55–2.20, 0.21–1.76 and 0.48–0.86, respectively, indicating a hydrothermal origin for the manganese mineralization and REEs enrichment. The (δ13CV‐PDB (−0.54 to −18.1%) and (δ18OSMOW (21.6 to 26.0%) characteristics of manganese ores reveal a mixed source of magmatic and organic matter. Moreover, the manganese ore, tuffaceous clay rock and Emeishan basalt have extremely similar REE fractionation characteristic, suggesting REEs enrichment and manganese mineralization have been mainly origin from hydrothermal fluids. [ABSTRACT FROM AUTHOR]

The Datangpo‐type manganese ore deposits, which formed during the Nanhuan (Cryogenian) period and are located in northeastern Guizhou and adjacent areas, are one of the most important manganese resources in China, showing good prospecting potential. Many middle‐to‐large deposits, and even super‐large mineral deposits, have been discovered. However, the genesis of manganese ore deposits is still controversial and remains a long‐standing source of debate; there are several viewpoints including biogenesis, hydrothermal sedimentation, gravity flows, cold‐spring carbonates, etc. Geochemical data from several manganese ore deposits show that there are positive correlations between Al2O3 and TiO2, SiO2, K2O, and Na2O, and strong negative correlations between Al2O3 and CaO, MgO, and MnO in black shales and manganese ores. U, Mo, and V show distinct enrichment in black shales and inconspicuous enrichment in Mn ores. Ba and Rb show strong positive correlations with K2O in manganese ores. Cu, Ni, and Zn show clear correlations with total iron in both manganese ores and black shales. ∑REE of manganese ores has a large range with evident positive Ce anomalies and positive Eu anomalies. The Post Archean Australian Shale (PAAS) normalized rare earth element (REE) distribution patterns of manganese ores present pronounced middle rare earth element (MREE) enrichment, producing "hat‐shaped" REE plots. ∑REE of black shales is more variable compared with PAAS, and the PAAS‐normalized REE distribution patterns appear as "flat‐shaped" REE plots, lacking evident anomaly characteristics. δ13C values of carbonate in both manganese ores and the black shales show observable negative excursions. The comprehensive analysis suggests that the black shales formed in a reducing and quiet water column, while the manganese ores formed in oxic muddy seawater, which resulted from periodic transgressions. There was an oxidation–reduction cycle of manganese between the top water body and the bottom water body caused by the transgressions during the early Datangpo, which resulted in the dissolution of manganese. Through the exchange of the euphotic zone water and the bottom water, and episodic inflow of oxygenated water, the manganese in the bottom water was oxidized to Mn‐oxyhydroxides and rapidly buried along with algae. In the early diagenetic stage, Mn‐oxyhydroxides were reduced and dissolved in the anoxic pore water and then transformed into Mn‐carbonates by reacting with HCO3− from the degradation of organic matter or from seawater. In the intervals between transgressions, continuous supplies of terrigenous clastics and the high productive rates of organic matter in the euphotic zone resulted in the deposition of the black shales enriched in organic matter. [ABSTRACT FROM AUTHOR]

The break-up of the supercontinent Rodinia in the late Neoproterozoic led to the formation of the Nanhua rift basin within the South China Block. The Datangpo-type manganese deposit, which developed in the Nanhua rift basin, is one of the most important types of manganese deposits in South China. Although it is widely accepted that deep sedimentary structures significantly affect the manganese ore system, the relationship between the manganese deposits in South China and the Nanhua rifting process is still unclear. The origin of the manganese ore layer remains controversial. In this paper, we integrated the audio-frequency magnetotelluric (AMT) data, gravity data, and comprehensive geological and borehole data analysis to characterize the structure of the Datangpo-type manganese deposit in Songtao, Guizhou Province. The resistivity and density models produced an inclined layered structure, which correlated well with the coeval sediment strata of the Nanhua rift basin. A high-resistivity cap was observed from the surface to a depth of 800 m, corresponding to the Cambrian Loushanguan ( ϵ 3 − 4 ls ) and Palang dolomite formation ( ϵ 2 p ), which has helped the storage of the manganese ore. The most significant low-resistivity anomaly (25–40 Ω·m) resides at a depth of 1400 m in the Nantuo (Nh3n) gravel sandstone and Datangpo (Nh2d) silty and carbonaceous shale, corresponding to the ore-forming layer. This distinct low-resistivity layer was possibly produced by aqueous fluids and pyrite in the syn-sedimentary fault and alteration zone. The accumulations of sulfide minerals in the rock samples suggest a possible anoxic-euxinic deposition environment during the manganese mineralization and precipitation. The fault revealed in the resistivity models is perhaps a previous fault zone produced by extension in the Nanhua rifting process, which provided migration and upwelling channels for ore-forming minerals. Based on our resistivity models, density models, and geological survey, the manganese ore-forming model was derived, which can help to provide geophysical evidence for the origin of the Datangpo-type manganese deposit. [ABSTRACT FROM AUTHOR]

[Display omitted] • New mineral-elemental-isotopic data for manganese deposits of the Permian Maokou Formation, northern Guizhou, South China. • Mn and Fe systems in biomats led to precipitated micro-laminae of microbiogenic minerals. • This manganese deposit is formed by the combination of hydrothermal and microbial activities. Economically important manganese deposits are hosted in the Middle Permian Maokou Formation of Zunyi, northern Guizhou, South China. During the Middle Permian, the intense rifting related to the initial stage of the Emeishan Large Igneous Province (ELIP) led to the development of carbonate platforms and inter-platform troughs. The manganese deposits occur in the transitional zone between carbonate platforms and troughs. Previous studies emphasized that the hydrothermal activities at the bottom of the trough basin controlled the formation of manganese deposits. In this study, new sedimentary, mineralogical, and stable isotope evidence are acquired from this manganese deposit, indicating that the microbially-mediated metallogenic mechanism also made an important contribution for the Middle Permian manganese deposition. The metallogenesis of this manganese deposit is highly like the combination of hydrothermal and microbial processes. Manganese ores in Zunyi are manganese carbonate, showing massive and clastic structures, no macroscopic nor microscopic lamination are found, samples are coarse-grained, diagenetically recrystallized with abundant mineralized microbial and microfossil biosignatures. FTIR, EPMA, and Raman analyses recognize micrometer-scale cyclic mineralogical assembly and help reconstruct the proposed new model of microbial manganese metallogenesis. Hydrothermal activity in the basin provided dissolved Mn2+ ions into the anoxic basal watermass. In the syngenetic stage, microbial systems could be subdivided into three categories: (1) cyanobacterial system, (2) Mn-biomat system and (3) Fe-biomat system. Cyanobacterial activity led to the precipitation of calcite, and it could be partially affected by Mn-metasomatism and transformed to Mn-bearing calcite. Mn-oxidizing microbes led to the precipitation of manganese bio-oxide (δ-MnO 2) near the redoxcline of the basin. Fe-biomat system was responsible for the precipitation of Fe-oxides (hematite) and Fe-hydroxides (ferrihydrite and lepidocrocite). After burial, manganese oxides reacted with the organic matter in the sediments through the microbially-mediated processes during the early diagenesis and the Mn-metasomatism of the cyanobacterial carbonate jointly contributed to formation of early diagenetic manganese carbonate ore. The redox fluctuations between oxic/suboxic and anoxic zones led to the re-oxidation process and resulted in cyclic marcasite. Anatase cycles observed in samples were interpreted as the diagenetic product of Fe-biomat system. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ore-forming fluids originated from ELIP volcanism-related hydrothermal activities. • The sedimentary environment likely evolved from anoxic through suboxic to oxic. • Permian Mn mineralization led by ELIP-induced tectono-hydrothermal activities and redox changes. The Permian manganese (Mn) ore belt lies in western South China Block, and contains many large-medium Mn deposits. However, the genesis and metallogenic mechanism of these deposits remains a matter of debate. Here we shed light on this issue based on new mineralogical, geochemical, and Sr isotope data from the Changgou Mn deposit in the Zunyi orefield (Guizhou, SW China). The Mn orebodies occur as lenses and layers, and are hosted in carbonaceous-siliceous limestone, carbonaceous mudstone, and tuffaceous claystone. The ores show a variety of structures (e.g., detrital, brecciated, massive, and banded) and complex mineral compositions (e.g., galena, sphalerite, siegenite, molybdenite, barite, rutile, and monazite). The ore samples are characterized by chalcophile and siderophile element enrichments, low Al 2 O 3 /TiO 2 ratios (mean 10.36), high and varying Mn/Fe ratios (1.26–4.71), distinctly high REY (rare earth and yttrium) contents (mean 766.46 ppm), and high La/Ce (mean 1.04) and low Y/Ho (mean 28.17) ratios. The footwall and ore samples have 87Sr/86Sr ratios of 0.706897 to 0.707093. Integrated mineralogical and geochemical signatures indicate that the ore-forming fluids were most probably originated from hydrothermal activities related to early-stage Emeishan Large Igneous Province (ELIP) subaqueous volcanism. Redox proxies reveal that sedimentary conditions evolved from euxinic-anoxic (footwall deposition), through anoxic-suboxic (Mn mineralization), to oxic (hanging-wall deposition). Such changes were probably resulted from a coeval eustatic sea-level drop and enhanced seawater oxygen supply. Manganese was likely initially enriched in form of Mn2+, and subsequently precipitated with oxidation, and then transformed into Mn carbonate during sediment diagenesis. To conclude, the tectono-hydrothermal activities and major environmental redox changes led by the ELIP volcanism have provided a favorable source-migration-sink system for the Mn mineralization. [ABSTRACT FROM AUTHOR]

Manganese and Fe have similar geochemical properties in the supergene environment. Separation of Mn and Fe is an important process for the formation of high-grade sedimentary manganese deposits. Large-scale manganese carbonate deposits (total reserves of approximately 700 Mt) were formed during the interglacial of the Sturtian and Marinoan in South China. The orebodies are hosted in the black rock series at the basal Datangpo Formation of the Cryogenian period. The Fe contents in ores range from 1.15 to 7.18 wt.%, with an average of 2.80 wt.%, and the average Mn/Fe ratio is 8.9, indicating a complete separation of Mn and Fe during the formation of manganese ores. Here, we present element data of manganese carbonates and sulfur isotopes of pyrite from the Dawu deposit, Guizhou, China, aiming to investigate the separation mechanism of Mn and Fe and the ore genesis. The Fe in ores mainly occurs as carbonate (FeCO3) and pyrite (FeS2). The Mn, Ca, Mg and Fe exist in the form of isomorphic substitutions in manganese carbonate. The contents of FeCO3 in manganese carbonates are similar in different deposits, with averages of 2.6–2.8 wt.%. The whole-rock Fe and S contents have an obvious positive correlation (R = 0.69), indicating that the difference of whole-rock Fe content mainly comes from the pyrite content. The δ34SV-CDT of pyrite varies from 40.0 to 48.3‰, indicating that the pyrite formed in a restricted basin where sulfate supply was insufficient and the sulfate concentrations were extremely low. Additionally, the whole-rock Fe content is negatively correlated with the δ34S values of the whole-rock and pyrite, with correlation coefficients of −0.78 and −0.83, respectively. Two stages of separations of Mn and Fe might have occurred during the mineralization processes. The reduced seawater became oxidized gradually after the Sturtian glaciation, and Fe2+ was oxidized and precipitated before Mn2+, which resulted in the first-stage separation of Mn and Fe. The residual Mn-rich and Fe-poor seawater flowed into the restricted rift basin. Mn and Fe were then precipitated in sediments as oxyhydroxide as the seawater was oxidized. At the early stage of diagenesis, organic matter was oxidized, and manganese oxyhydroxide was reduced, forming the manganese carbonate. H2S was insufficient in the restricted basin due to the extremely low sulfate concentration. The Fe2+ was re-released due to the lack of H2S, resulting in the second-stage separation of Mn and Fe. Finally, the manganese carbonate deposit with low Fe and very high δ34S was formed in the restricted basin after the Sturtian glaciation. [ABSTRACT FROM AUTHOR]

The article focuses on Geological Brigade No. 103 of Guizhou Geology and Mineral Exploration and Development Bureau discovered two super-large manganese deposits at Pujue and Taoziping in Songtao County, Guizhou Province, China. It mentions it is abundant manganese ore resources, with a potential economic value and tectonic denudation and karst erosion landform. It also mentions manganese deposits with the same synsedimentary fault.