MINERALOGICAL AND GEOCHEMICAL CHARACTERIZATION OF THE ARIZLI MN DEPOSIT (AFYONKARAHISAR, TURKEY): EVIDENCE FOR DIAGENETIC AND SUPERGENE ENRICHMENT

The Binkilic manganese deposit, occurring in the Congeria and Fish Series of the Oligocene in Thrace Basin, is associated with relatively rapid marine transgressions and regressions across older basement rock and is called as shallow-marine basin-margin deposit. The geochemical characteristics of the deposit were examined by means of major oxide, trace and rare elements (REE) contents and the origin of mineralization was discussed. The deposit contains lower Mn / Fe ratios than those of hydrothermal and sedimentary exhalative deposits. The concentrations of Ba, Co, Sr, Cu, Zn and Ni are closely related to the increase of manganese content and indicate the element’s nature in various manganese minerals. According to trace element spider diagram normalized to shale composite NA, the ore is clearly enriched in Sr, Ni while distinctly depleted in Rb. The chemical analysis results indicated that total REE contents of the samples are relatively low and the ratio of ΣLREE/ΣHREE shows a primary enrichment for LREE that has occurred during the Mn oxidation process. The increase in total LREE is mainly associated with the amount of terrigenous material that was transported in the depositional environment. The chondrite-normalized REE patterns are remarkably similar, yielding HREE-depleted curves with a small negative Ce and middle positive Eu anomalies and reflect their same origin of ore source. The Ce values and Ce/Ce* ratios show that the Binkilic deposit is mainly associated with the marine basin and the ore is formed in both anoxic and oxic conditions. The major oxide, trace element and REE assessments indicated that the Binkilic Mn deposit occurred as a diagenetic type of Mn deposit with terrigenous material addition, but some manganese oxides are related to the upwelling of reducing waters containing abundant organic matter and dissolved Mn to the shallow-marine areas.

Manganese (Mn) oxidation in marine environments requires oxygen (O2 ) or other reactive oxygen species in the water column, and widespread Mn oxide deposition in ancient sedimentary rocks has long been used as a proxy for oxidation. The oxygenation of Earth's atmosphere and oceans across the Archean-Proterozoic boundary are associated with massive Mn deposits, whereas the interval from 1.8-1.0Ga is generally believed to be a time of low atmospheric oxygen with an apparent hiatus in sedimentary Mn deposition. Here, we report geochemical and mineralogical analyses from 1.1Ga manganiferous marine-shelf siltstones from the Bangemall Supergroup, Western Australia, which underlie recently discovered economically significant manganese deposits. Layers bearing Mn carbonate microspheres, comparable with major global Mn deposits, reveal that intense periods of sedimentary Mn deposition occurred in the late Mesoproterozoic. Iron geochemical data suggest anoxic-ferruginous seafloor conditions at the onset of Mn deposition, followed by oxic conditions in the water column as Mn deposition persisted and eventually ceased. These data imply there was spatially widespread surface oxygenation ~1.1Ga with sufficiently oxic conditions in shelf environments to oxidize marine Mn(II). Comparable large stratiform Mn carbonate deposits also occur in ~1.4Ga marine siltstones hosted in underlying sedimentary units. These deposits are greater or at least commensurate in scale (tonnage) to those that followed the major oxygenation transitions from the Neoproterozoic. Such a period of sedimentary manganogenesis is inconsistent with a model of persistently low O2 throughout the entirety of the Mesoproterozoic and provides robust evidence for dynamic redox changes in the mid to late Mesoproterozoic.

Ancient manganese (Mn) deposits are primarily characterized by the presence of Mn(II) carbonates that likely formed by the diagenetic reduction of precursor Mn(IV) oxides. As such, Precambrian sedimentary Mn deposits have been used as a line of evidence for the evolution of oxygen in Earth’s surface environments. However, recent studies have shown that these Mn(II)-carbonates have the ability to directly accumulate within anoxic water columns, where free oxygen does not play a role in their formation. This alternative pathway casts uncertainty on the robustness of using ancient Mn deposits to constrain the redox fabric of the past marine water columns. Here, we investigate the Wafangzi Mn and Fe ore deposit from the 1.45 billion-year-old Tieling Formation, North China. The deposit contains Mn(II, III) mineral phases (hausmannite, braunite) as inclusions, or unreacted residues, trapped within Mn(II) carbonate (Ca-rhodochrosite). Some nodules and oolites of Mn(II) and Fe(II)-carbonate phases are also present and display a banded structure with concentric rings. Mn(III) oxide (manganite) is present in a paragenetic assemblage along with hematite and replacement textures with braunite. The negative carbon isotope composition (δ13C, –7‰ to –4‰) from Mn(II) carbonate samples in the Wafangzi Mn deposit which are distinct from that of contemporaneous seawater (~0‰), along with petrographic and speciation analyses, collectively suggest that the Mn(II, III)- and Fe(II)-bearing mineral phases formed through the diagenetic reduction of primary Mn(IV)/Fe(III) minerals coupled to the oxidation of organic matter. Therefore, the Wafangzi Mn deposit suggests the presence of sufficiently oxygenated marine waters, overlying anoxic ferruginous deeper waters with a transitional manganous water layer that could have driven the redox cycling of Mn, Fe, and C. Given the contemporaneous economic Mn deposits in the 1.45 Ga Ullawarra Formation in Western Australia, our findings imply the existence of a transient, and perhaps widespread, pulsed oxygenation event in the mid-Proterozoic oceans.

Meteorite impacts are among the very few processes common to all planetary bodies with solid surfaces. Among the effects of impact on water-bearing targets is the formation of post-impact hydrothermal systems and associated mineral deposits. The Haughton impact structure (Devon Island, Nunavut, Canada, 75.2 °N, 89.5 °W) hosts a variety of hydrothermal mineral deposits that preserve assemblages of primary hydrothermal minerals commonly associated with secondary oxidative/hydrous weathering products. Hydrothermal mineral deposits at Haughton include intra-breccia calcite-marcasite vugs, small intra-breccia calcite or quartz vugs, intra-breccia gypsum megacryst vugs, hydrothermal pipe structures and associated surface "gossans," banded Fe-oxyhydroxide deposits, and calcite and quartz veins and coatings in shattered target rocks. Of particular importance are sulfide-rich deposits and their associated assemblage of weathering products. Hydrothermal mineral assemblages were characterized structurally, texturally, and geochemically with X-ray diffraction, micro X-ray diffraction, optical and electron microscopy, and inductively coupled plasma atomic emission spectroscopy. Primary sulfides (marcasite and pyrite) are commonly associated with alteration minerals, including jarosite (K,Na,H(3)O)Fe(3)(SO(4))(2)(OH)(6), rozenite FeSO(4)·4(H(2)O), copiapite (Fe,Mg)Fe(4)(SO(4))(6)(OH)(2)·20(H(2)O), fibroferrite Fe(SO(4))(OH)·5(H(2)O), melanterite FeSO(4)·7(H(2)O), szomolnokite FeSO(4)·H(2)O, goethite α-FeO(OH), lepidocrocite γ-FeO(OH) and ferrihydrite Fe(2)O(3)·0.5(H(2)O). These alteration assemblages are consistent with geochemical conditions that were locally very different from the predominantly circumneutral, carbonate-buffered environment at Haughton. Mineral assemblages associated with primary hydrothermal activity, and the weathering products of such deposits, provide constraints on possible microbial activity in the post-impact environment. The initial period of active hydrothermal circulation produced primary mineral assemblages, including Fe sulfides, and was succeeded by a period dominated by oxidation and low-temperature hydration of primary minerals by surface waters. Active hydrothermal circulation can enable the rapid delivery of nutrients to microbes. Nutrient availability following the cessation of hydrothermal circulation is likely more restricted; therefore, the biological importance of chemical energy from hydrothermal mineral deposits increases with time. Weathering of primary hydrothermal deposits and dissolution and reprecipitation of mobile weathering products also create many potential habitats for endolithic microbes. They also provide a mechanism that may preserve biological materials, potentially over geological timescales.

Numerous Early Cretaceous Mn oxide and Mn-Fe deposits are distributed in the Tokoro belt, northeastern Hokkaido, Japan. The Mn oxide deposits usually occur in the southwestern part of the belt and within bedded cherts whereas the Mn-Fe deposits are restricted to the northeastern part of the belt and occur between bedded cherts and underlying basaltic pillow lava.The Mn oxide ores are characterized by low Fe/Mn ratios, and the trace element concentrations and rare earth element (REE) patterns are similar to those of the submarine hydrothermal Mn deposits. Distribution patterns of trace elements (Co, Ni, Cu, and Zn) and REE in the Mn oxide ores determine two types of deposits: hydrogenous deposits which have relatively high concentrations, and submarine hydrothermal deposits which have low concentrations.These compositional trends and geologic evidences of the Tokoro Mn deposits suggest that the Fe phases precipitated first closer to their source whereas the Mn phases deposited later at a distance from their source. Some hydrogenous effects on the Mn oxide deposits are due to the adsorption of trace elements from seawater. Trace element concentrations of Tokoro Mn oxide deposits show that they formed within 40 km from their source.

Immobilization of perrhenate using synthetic pyrite particles: Effectiveness and remobilization potential

کانسار منگنز شهرستانک در جنوب استان قم و 12 کیلومتری جنوب غربی شهرستان کهک واقع شده است. ایـن کانسار به لحاظ سنگ شناسی و چینه شناسی دارای تنــــوع زیادی است؛ به طوری‌که واحدهای مختلف سنگی شامل 1) سنگهای آتشفشانـی- رسوبـی ائوسن میانی- بالایی، 2) واحدهای کنگلومرایی و ماسه سنگی قرمز زیرین به سن الیگوسن، 3) ته نشستهای آهک و مـارن (سازند قم) به سن الیگومیــوسن، 4) دایک های حد‌واسط تا بـــازیک به سن ائوسن و میــوسن پایانـــی در منطقه قابل مشاهــده است. بالا بـودن میانگیــن مقـادیـر Mn/Fe (33/11) و Si/Al (86/4)، پاییــن بودن مقادیر میانگیــن فلزات کمیـاب به ویــژه فلـزات Co ( 40/11 پی ی ام)، Ni (24 پی ی ام) و Cu (85/81 پی پی ام)، ، پایین بودن مقدار میانگین آنومالی *Ce (99/0 پی پی ام) و بالابودن مقادیر SiO2، Mn، Fe، Ba، Zn، As و Sr در کانسنگ منگنز شهرستانک به‌عنوان شواهدی از غنی‌شدگی و تخلیه Mn از گرمابیهای برون‌دمی هستند و نقش فرآیندهای آب‌زاد در پیدایش این کانسار را ناچیز می نماید. شواهد زمین شناسی و زمین شیمیایی گویای نهشت کانه ها از گرمابیهای زیردریایی (برون‌دمی) در بستر حوضه اقیانوسی نئوتتیس در زمان ائوسن میانی تا پایانــی در واحدهای سنگی توف آهکی با میان لایه هایی از آهک میکرایتــی و واحد سنگ آهک ماسه ای می باشد. لذا در مورد شرایط تشکیل این کانسار می توان عنوان کرد که، فعالیتهای گرمابی شدید باعث شسته شدن گدازه های بازالتی و آندزیتی شده و عناصر Mn، Fe، Si، Ba، Sr، As توسط فعالیتهای برون‌دمی- آتشفشانی؛ از طریق گسلهای همزمان با رسوب گذاری وارد حوضه رسوبی گردیده و با پس‌روی دریا و ایجاد شرایط اکسیدی کانیهای اکسی هیدروکسیدی اولیه منگنز ته نشست شده اند.

Effects of pH and dissolved oxygen on Cr(VI) removal in Fe(0)/H2O systems

Introduction The Mn mineralization occurs in the northeastern segment of the Sabzevar zone (SZ), north of the Central Iranian Microcontinent (CIM). This Zone (SZ) is located between the CIM fragmentation in the south and the Kopeh dagh sedimentary sequence in the north. The ore deposits of the northeastern segment of the Sabzevar zone can be divided into three groups, each with different metal association and spatial distribution and each related to a major geodynamic event. The first mineralization with associated Ordovician host rock is characterized by Taknar polymetallic (Fe-rich) massive sulfide deposit. The Cretaceous mineralization consists of Cr deposits associated with serpentinized peridotites, Cyprus type VMS, Mn deposit in pillow lava, volcano-sedimentary hosted Besshi type VMS and Mn deposit. Paleogene mineralization in eastern segment of the Sabzevar zone began with porphyry deposits, Cu Red Bed mineralization occurs in the Paleogene sandy red marl. Materials and methods A field study and sampling was performed during the autumn of 2012. To assess the geochemical characteristics of 48 systematic samples (least fractured and altered) of ore-bearing layers and host rocks were collected from the deposit for polished thin section examination. In order to correctly characterize their chemical compositions, 15 least-altered and fractured samples were chosen for major elements analysis. Results The Late Cretaceous volcano-sedimentary sequence in south-southwest of Sabzevar hosts numerous manganese mineralization. The sequence based on the stratigraphic position, age and composition of the rocks, can be divided into two lower and upper parts. The lower part or K2tv unit mainly formed from marine sediments interbedded with volcanic rocks. The sedimentary rocks of this part include silicified tuff, chert, shale and sandstone, and the volcanic rocks involve pyroclastic rocks of various composition, rhyolite, dacite and andesitic lava. The upper part or LMV unit comprised of limestone, marl and volcanic rocks, overlies concordantly on the lower part (K2tv). The manganese mineralization within the host volcano-sedimentary sequence, based on stratigraphic position, relative age and type of host rocks involved the two horizons: the first horizon (Mn Ia, Ib) consisting of Benesbourd (Masoudi, 2008), Nudeh (Nasrolahi et al., 2012), Homaie (Nasiri et al., 2010), Goft and Manganese Gostar Khavar Zamin deposits, occurred in the lower part of the sequence (K2tv unit) and is hosted by red tuffs. The second horizon (Mn II) comprising of Zakeri (Taghizadeh et al., 2012), Cheshmeh Safeid, Mohammad Abad Oryan and Chah Setareh deposits, is hosted by marly-carbonate tuffs and locates within the upper part of the sequence (LMV unit) (Maghfouri, 2012). Geometry and shape of the ore bodies in various deposits are as stratiform, layered, parallel and concordant with layering of the host rocks. Textures of the ores include massive, lenticular, banded, laminated and disseminated. Mineralogy of the ores in the two ore horizons is simple and similar and is dominated by pyrolusite, psilomelane and braunite. Gangue minerals are predominantly the host rock-forming minerals including quartz, chlorite and feldspar. Discussion Geochemical data, structures and textures, stratigraphic position and lithologic characteristics of the host rocks represent that manganese reserves in south-southwest Sabzevar were formed as sedimentary-exhalative. Acknowledgements The authors are grateful to the Tarbiat Modares University Grant Commission for research funding. References Maghfouri, S., 2012. Geology, Mineralogy, Geochemistry and Genesis of Cu Mineralization within Late Cretaceous Volcano-Sedimentary Sequence in Southwest of Sabzevar, with emphasis on the Nudeh Deposit. M.Sc. Thesis, Tarbiat Modares University, Tehran, Iran, 312 pp. (in Persian) Masoudi, M., 2008. Geology, mineralogy, geochemistry and genesis of Benesbourd Mn deposit in the Southwest Sabzevar. M.Sc. Thesis, Tehran Islamic Azad University, Iran, 100 pp. (in Persian) Nasiri, F., Lotfi, M. and Jafari, M., 2010. Mineralogical studies on the Homaei manganese deposit in southwest of Sabzevar. 30th Symposium on Geosciences, Geological Survey of Iran, Tehran, Iran. (in Persian) Nasrollahi, S., Mousivand, F. and Ghasemi, H., 2012. Nudeh Mn deposit in the upper Cretaceous volcano- sedimentary sequence, Sabzevar subzone. 31th Symposium on Geosciences, Geological Survey of Iran, Tehran, Iran. (in Persian) Taghizadeh, S., Mousivand, F. and Ghasemi, H., 2012. Zakeri Mn deposit, example of exhalative mineralization in the southwest Sabzevar. 31th Symposium on Geosciences, Geological Survey of Iran, Tehran, Iran. (in Persian)

Geology, geochemistry and genesis of the Godar Sabz Mn deposit in the Baft region, Iran

Bangka Island is an important tin producer in Indonesia, mostly from the secondary tin deposits. However, the secondary tin deposit is depleting, causing further exploration shifted to the primary tin mineral. The purpose of this study is to make a mineralization model of primary tin deposit in Bangka Island. Methods that implemented in this study are petrographic analysis, mineragraphic analysis, XRD (X-Ray Diffraction), and XRF (X-Ray Fluorescence) analysis. The studied rock samples that consisted of granite, meta-sandstone, and sandstone. Some of the rocks are altered rocks with varying intensity. Petrographic and mineragraphic analysis show the presence of minerals that indicate the primary tin deposits, such as cassiterite, tourmaline, topaz, sericite, pyrite, and sphalerite. XRF analysis shows data about the value of Sn elements so that they can be classified into two classes, very high grade (> 800 ppm), and low grade (100–200 ppm). XRD analysis is necessary to do to determine the type and intensity of alterations that occur in the study area. The results of each analysis will provide supporting information regarding the primary tin mineralization process in Bangka Island.

The Minghuazhen Formation in the Cangdong Sag of the Bohai Bay Basin is a key sedimentary unit for investigating regional provenance evolution, paleoclimate variations, and hydrocarbon potential in Eastern China. This study integrates mineralogical and geochemical analyses to explore sedimentary characteristics. Techniques include X-ray diffraction (XRD), major/trace element compositions, rare earth element (REE) distributions, and organic carbon content. XRD data and elemental ratios (e.g., Al/Ti, Zr/Sc) suggest a predominant felsic provenance, sourced from acidic magmatic rocks. The enrichment with light rare earth elements (LREE: La–Eu) and notable negative Eu anomalies in the REE patterns support the interpretation of a provenance from the Taihangshan and Yanshan Orogenic Belts. Geochemical proxies, such as the Chemical Index of Alteration (CIA) and trace element ratios (e.g., U/Th, V/Cr, Ni/Co), indicate a warm and humid depositional environment, characterized by predominantly oxic freshwater conditions. Organic geochemical parameters, including total organic carbon (TOC), total nitrogen (TN), and C/N ratios, suggest that organic matter primarily originates from aquatic algae and plankton, with C/N values predominantly below 10 and a strong correlation between TOC and TN. The weak correlation between TOC and total carbon (TC) indicates that the organic carbon is mainly biological in origin rather than carbonate-derived. Although the warm and humid climate promoted the production of organic matter, the prevailing oxic conditions hindered its preservation, resulting in a relatively low hydrocarbon generation potential within the Minghuazhen Formation of the Cangdong Sag. These findings provide new insights into the sedimentary evolution and hydrocarbon potential of the Bohai Bay Basin.

Freshly prepared carbonate structural Fe(II) (CSF) was used to immobilize As(III) and As(V) in wastewater under oxic and anoxic conditions. Dissolved oxygen was found to exert opposite effects on these two arsenic species. The sorption density of As(III) was higher under oxic conditions, whereas that of As(V) was higher under anoxic conditions. X-ray diffraction and infrared spectroscopic analyses indicated that crystalline parasymplesite (Fe(II)3(AsO4)2·8H2O) was formed when As(V) was removed under anoxic conditions, while an amorphous Fe-As-containing precipitate was formed when As(III) was removed under oxic conditions. The distribution of arsenic and iron between the solution and sediments suggested that the oxidation of structural Fe(II) promoted coprecipitation process and inhibited surface complexation. X-ray photoelectron spectroscopic analyses revealed that more As(III) was oxidized under oxic condition, which contributed to a higher sorption capacity for As(III). The formation of parasymplesite through surface complexation/precipitation was proposed to be more effective for the removal of As(V) by CSF, while As(III) was more efficiently removed through coprecipitation. Together, the results suggest that CSF may be an effective material for sequestering both As(III) and As(V). In addition, attention should be paid to the dissolved oxygen content when remediating different arsenic species.

Thirty surface sediment samples collected from Ariyankuppam (N = 12) and Chunnambar estuaries (N = 18) located along the coast of Pondicherry, India, are analyzed to understand the nature of weathering and provenance. The granulometric study reveals that sediments are poorly sorted, positively skewed and platykurtic to leptokurtic in nature. The abundance and inverse relationship of SiO2 with other major oxides signify the detention of silica within quartz. The Index of Chemical Variability (ICV) suggests that sediments are compositionally immature and are derived from less weathered source rock. The weathering indices such as the Chemical Index of Alteration (CIA); Chemical Index of Weathering (CIW); Plagioclase Index of Alteration (PIA), and A-CN-K diagram also suggest less intense weathering of parent rocks. The major and trace element ratios viz. Al2O3/TiO2, TiO2/Zr, Cr/V and Y/Ni and discrimination diagrams indicate that estuarine sediment is derived from felsic and intermediate provenance.

Mafic dyke swarms of the Baltica-Iapetus transition, Seve Nappe Complex of the Sarek Mts., Swedish Caledonides With respect to petrography and chemistry, the Sarek dolerites compare excellently to T-MORB as far as REE abundance patterns and some trace element ratios are concerned: chondrite normalized (La/Sm) = 0.77–1.04 and (La/Yb) = 1.2–2.9; Zr/Nb = 8.3–11.6; Zr/Y = 2.8–4.8; Y/Nb = 1.9–4.3. However, high abundances of LIL elements and straddling of boundaries to fields of destructive margins in Nb-Y-Zr and Hf-Ta-Th discrimination diagrams indicate a mixed magmatectonic signature. In this respect, the Sarek dolerites compare to basalts of ensialic back-arc basins e.g. the Gulf of California. However, such a setting is incompatible with our present knowledge about the Baltoscandian scenario 500–600 Ma ago, unless the Sarek sheeted dyke complex was part of the Laurentian passive margin. The favoured interpretation is a situation similar to the present-day opening of the South Atlantic Ocean, where...