scholarly journals Mineralogical - geochemical characteristics of gold mineralization and its potential in the Tuong Duong area, Nghe An province

2021 ◽  
Vol 62 (3b) ◽  
pp. 30-40
Author(s):  
Hung The Khuong ◽  
Dung Tri Ha ◽  
Keyword(s):  
Gold Mineralization ◽  
Direct Calculation ◽  
Gold Deposits ◽  
Mineral Deposit ◽  
Thin Sections ◽  
Icp Ms ◽  
Deposit Type ◽  
Gold Mineral ◽  
Hydrothermal Activities ◽  
Potential Area

Tuong Duong area, Nghe An province is considered as a high potential area of gold deposits such as the Yen Na - Yen Tinh, Ban Bon, Xieng Lip, and Na Khom gold occurrences. Based on synthesizing, geological processing data, analysis and complement of the 15 thin sections, 10 thick sections, 02 scanning electron microscope and 05 ICP - MS samples, results show that the gold mineralization has fomed from hydrothermal activities at low - moderate temperature, belonging to quartz - sulfur - gold mineral deposit type. The gold contents in orebodies vary from medium to high values, with average contents ranging from 0.8÷6.55 (g/ton). Results also provide an overview of the prospect of gold resources, serving as a basis for determining the Au prospective areas in Tuong Duong, Nghe An province. The direct calculation method for metallization parameters and Huvo methods are applied in this paper to estimate gold resources in the study area, resulting in 2.21 tons of Au - metal.

scholarly journals MINERAL POTENTIAL MAPPING USING GEOGRAPHIC INFORMATION SYSTEMS (GIS) FOR GOLD MINERALIZATION IN WEST JAVA, INDONESIA

2015 ◽  
Vol 7 (1) ◽  
pp. 61
Author(s):  
Seang Sirisokha ◽  
Lucas Donny Setijadji ◽  
I Wayan Warmada
Keyword(s):  
Gold Mineralization ◽  
Spatial Association ◽  
Geographic Information ◽  
Gold Deposits ◽  
Weights Of Evidence ◽  
Rock Unit ◽  
West Java ◽  
Mineral Potential ◽  
Potential Mapping ◽  
Potential Area

Western Java is a part of the Sunda Banda magmatic belt. This belt is well known to be host for several gold deposits in Indonesia, the distribution of 107 Au occurrences in this area was examined in terms of spatial association with various geological phenomena. The goal of this project is to use GIS to conduct weights of evidence (WofE) model for gold mineralization in West Java, Indonesia. A Geographic Information System (GIS) is a computer system for capturing, storing, querying, analyzing, and displaying geospatial data and weight of evidence method is one of the most important datadriven methods for mapping in GIS. The method is a probability based on technique for mapping mineral potential using the spatial distribution of known mineral occurrences. Therefore this method is very useful for gold potential mapping. There are six evidences maps such as NE–SW lineaments NW–SE Lineament, host rocks, heat sources, clay alteration and limonitic alteration, have been combined using a weights of evidence model to predict gold potential in West Java. The best predictive map generated by this method defines 21.62% (9902 km) of study area as favourable zones for gold mineralization further exploration work. It predicts correctly 74 (92.5%) of the 80 model deposits and predicts correctly 26 (96.35%) of the 27 validation deposits, has 6 main 2 prospective target for future exploration are located in Bayah Dome, southern mountain, Honjie Igneous Complex and Bogor zone, Purwakarta. Bayah Dome is highest potential area for gold deposit like Gunung Pongor, Cikidang, Cirotan, Ciawitali, Cikotok destricts and other deposits. The potential area of Au occurrences in research area is associated with NE–SW and NW–SE structure/ lineaments, dominated surrounding the Tertiary intrusive rock unit and hosted in Miocene to Pleistocene lithology rock unit.

Classification of pyrite types using fractal and stepwise factor analyses in the Chah Zard gold-silver epithermal deposit, Central Iran

2020 ◽  
Vol 20 (4) ◽  
pp. 496-508
Author(s):  
Hossein Kouhestani ◽  
Majid Ghaderi ◽  
Peyman Afzal ◽  
Khin Zaw
Keyword(s):  
Inductively Coupled Plasma ◽  
Gold Mineralization ◽  
Study Data ◽  
Gold Deposits ◽  
Central Iran ◽  
Factor Analyses ◽  
Icp Ms ◽  
Gold Silver ◽  
Log Ratio

The major target of this research is the classification of pyrite types using fractal and stepwise factor analyses in the Chah Zard ore deposit, Central Iran. The ore occurs within a breccia/vein type and the major ore mineral hosting gold mineralization is pyrite. In this study, data were selected using optical, scanning electron microscopy (SEM) and backscattered electron observations as well as laser ablation-inductively coupled plasma–mass spectrometry (LA-ICP–MS) analysis. Conventional interpretations represent four gold-bearing pyrite types of various textures including fractured and porous Py1, oscillatory-rimmed and simple-zoned Py2, colloform Py3 and inclusion-rich Py4. The stepwise factor process was performed on the centred log ratio (clr) transformed data in two phases and Au was grouped with As, Te, Ni and Co in the second factor from the second stage (F2-2). Also, C-N fractal modelling was performed on the As, Au, Te and F2-2 values, all of which demonstrate multifractal nature. Four populations were separated based on F2-2 values and the C-N log–log plot. The main gold mineralization starts from 32 ppm, 2.8%, 7.94 ppm and 1.26 for Au, As, Te concentrations and F2-2, respectively, based on the C-N fractal modelling. These values are correlated with inclusion-rich Py4 and simple-zoned and oscillatory-rimmed Py2. The results obtained in this study show that fractal interpretation of LA-ICP–MS data by stepwise factor analysis may provide a suitable tool for the recognition of ore mineralization in epithermal gold deposits.

Geochemistry, petrogenesis and tectonic implications of granitic plutons at the Liziyuan orogenic goldfield in the Western Qinling Orogen, central China

2012 ◽  
Vol 150 (1) ◽  
pp. 50-71 ◽  
Author(s):  
TAO YANG ◽  
LAIMIN ZHU ◽  
FEI WANG ◽  
HUJUN GONG ◽  
RUKUI LU
Keyword(s):  
Gold Mineralization ◽  
Early Stage ◽  
Gold Deposits ◽  
Central China ◽  
Late Triassic ◽  
Trace Element Geochemistry ◽  
Qinling Orogen ◽  
Element Geochemistry ◽  
Medium Temperature ◽  
Icp Ms

AbstractThe Liziyuan goldfield is located along the northern margin of the western part of the Qinling Orogen (WQO). The goldfield consists of five gold-only deposits hosted by metavolcanic rocks, and one polymetallic (Au–Ag–Pb) deposit hosted by the Tianzishan Monzogranite. As the Liziyuan goldfield appears to be spatially and temporally related to the Jiancaowan Porphyry, the study of the deposit provides a crucial insight into the relationship between tectonic-magmatic events and gold metallogenesis in the WQO. In this paper, we present whole-rock major and trace element geochemistry, and in situ zircon U–Pb and Lu–Hf isotopic data from the Tianzishan Monzogranite and Jiancaowan Porphyry. The two granitic plutons are enriched in LILEs and LREEs, depleted in HFSEs and have zircon εHf(t) values between −14.1 and −5.1 for the Tianzishan Monzogranite and between −21.0 and −8.4 for the Jiancaowan Porphyry. These characteristics indicate that the granites are derived from the crust. The Tianzishan Monzogranite has LA-ICP-MS zircon U–Pb ages of 256.1 ± 3.7 to 260.0 ± 2.1 Ma, which suggests that it was emplaced in the WQO during the convergence of the North and South (Yangtze) China cratons in the early stage of the Qinling Orogeny. In contrast, the porphyry has a LA-ICP-MS zircon U–Pb age of 229.2 ± 1.2 Ma, which is younger than the peak collision age, but corresponds to the widespread Late Triassic post-collisional granitic plutons in the WQO. The Tianzishan Monzogranite has somewhat higher Sr contents (196–631 ppm), lower Y (2.23–19.6 ppm) and Yb (0.20–2.01 ppm) contents, and a positive Eu/Eu* averaging 1.15. These characteristics suggest the pluton was derived from partial melting of the thickened crust. In contrast, the relatively higher MgO content (0.85–2.08 wt%) and Mg no. (43.4–58.2) of the Jiancaowan Porphyry indicates that insignificant amounts of subcontinental lithospheric mantle-derived mafic melts were involved in the generation of the magma. The Liziyuan goldfield is hosted by faults in greenschist-facies metamorphic rocks. Fluid inclusion studies suggest that gold was precipitated from CO2-rich, low-salinity and medium temperature fluids. This feature is consistent with the other orogenic gold deposits throughout the world. The field relationships and zircon U–Pb ages of the two granitic plutons suggest that gold mineralization is coeval with or slightly younger than the emplacement of the Jiancaowan Porphyry. Therefore, both the porphyry and deposit formed during the post-collisional stage of the Qinling Orogen.

scholarly journals NATIVE GOLD OF UKRAINE, PREREQUISITES FOR THE CREATION OF ITS CRYSTALLOGENETIC DETERMINANT

2018 ◽  
pp. 6-18
Author(s):  
V. Kvasnytsya ◽  
I. Kvasnytsya
Keyword(s):  
Native Gold ◽  
Gold Mineralization ◽  
Gold Deposits ◽  
Ukrainian Shield ◽  
Low Grade ◽  
Near Surface ◽  
Mineral Associations ◽  
Gold Mineral ◽  
Impurity Elements

The main developments in the typomorphism of native gold from various depth and uneven-aged deposits are described briefly, and the basis for creating a native gold crystallogenetic determinant of Ukraine is proposed. A significant geological material for the most known occurrences of gold mineralization in Ukraine was collected and processed, and a certain stage of studying the crystallomorphology and chemical composition of visible native gold was completed. The crystals of native gold from the occurrences and deposits on the Ukrainian Shield, the Donbass, in the Ukrainian Carpathians and the Transcarpathia have been characterized. The methods of native gold studying, such as goniometry, scanning electron microscopy, and microprobe analysis were used. The typomorphic features of native gold from the main deposits and ore occurrences of Ukraine are determined, which can be used in the practice of predictive, geological prospecting and prospecting for gold. The native gold of the Ukrainian Shield is attributed to deep mineralization, the Ukrainian Carpathians and the Donbass - to medium-deep mineralization and the Transcarpathia – to shallow mineralization. It is shown that in Ukraine, as in other gold-bearing regions of the world, the transition from an ancient deep and medium deep mineralization to a younger near-surface mineralization increases the number of well-formed crystals of native gold and their morphology becomes more complex, individuals of isometric form are replaced by distorted crystals, the role of dendrites and complex twins increases, the grade of gold becomes lower and its heterogeneity grows, the composition and concentration of impurity elements change. The crystallomorphology of the shallow low-grade native gold of the Transcarpathia is diverse (the Muzhi³ve deposit, quartz-barite ores). Unique crystals here are complex twins of cube-octahedrons of native gold. Specificity of medium-deep medium-grade native gold from some ore occurrences of the Donbass is rhombododecahedral faceting of its crystals. Crystallomorphology of deep high-grade native gold from deposits and ore occurrences of the Ukrainian Shield is monotonous. Research data on native gold from known deposits and ore occurrences of Ukraine are generalized and systematization of endogenous gold ore occurrences of Ukraine is made on this basis. A model of a crystallogenetic determinant of native gold of Ukraine is proposed, in which the following main sections are emphasized: 1) native gold mineral associations; 2) chemical-structural and other features of gold crystals; 3) gold crystals morphology; 4) gold crystals anatomy; 5) the method and mechanism of gold crystals growth; 6 ) typomorphic signs of gold crystals; 7) genesis of gold. As an example, a crystallogenetic determinant of native gold from the Proterozoic conglomerates of the Bilokorovychi structure on the Volyn megablock is given. The mineralogical criteria of gold mineralization are outlined and some general conclusions concerning genesis, forecast and searches of gold deposits in Ukraine are made.

scholarly journals Multi-scale interactions of geological processes during mineralization: cascade dynamics model and multifractal simulation

2011 ◽  
Vol 18 (2) ◽  
pp. 161-170 ◽  
Author(s):  
L. Yao ◽  
Q. Cheng
Keyword(s):  
Gold Mineralization ◽  
Quantitative Model ◽  
Gold Deposits ◽  
Mineral Deposit ◽  
Point Of View ◽  
Cascade Process ◽  
Statistical Point ◽  
Mineral Potential ◽  
Geological Processes ◽  
Evidence Model

Abstract. Relations between mineralization and certain geological processes are established mostly by geologist's knowledge of field observations. However, these relations are descriptive and a quantitative model of how certain geological processes strengthen or hinder mineralization is not clear, that is to say, the mechanism of the interactions between mineralization and the geological framework has not been thoroughly studied. The dynamics behind these interactions are key in the understanding of fractal or multifractal formations caused by mineralization, among which singularities arise due to anomalous concentration of metals in narrow space. From a statistical point of view, we think that cascade dynamics play an important role in mineralization and studying them can reveal the nature of the various interactions throughout the process. We have constructed a multiplicative cascade model to simulate these dynamics. The probabilities of mineral deposit occurrences are used to represent direct results of mineralization. Multifractal simulation of probabilities of mineral potential based on our model is exemplified by a case study dealing with hydrothermal gold deposits in southern Nova Scotia, Canada. The extent of the impacts of certain geological processes on gold mineralization is related to the scale of the cascade process, especially to the maximum cascade division number nmax. Our research helps to understand how the singularity occurs during mineralization, which remains unanswered up to now, and the simulation may provide a more accurate distribution of mineral deposit occurrences that can be used to improve the results of the weights of evidence model in mapping mineral potential.

scholarly journals Source of the Chaoyangzhai Gold Deposit, Southeast Guizhou: Constraints from LA-ICP-MS Zircon U–Pb Dating, Whole-rock Geochemistry and In Situ Sulfur Isotopes

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 235 ◽  
Author(s):  
Hinyuen Tsang ◽  
Jingya Cao ◽  
Xiaoyong Yang
Keyword(s):  
Gold Deposit ◽  
Quartz Vein ◽  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Gold Mineralization ◽  
Sulfur Isotopes ◽  
Gold Deposits ◽  
Sulfur Source ◽  
Icp Ms ◽  
Gold Bearing

The Chaoyangzhai gold deposit is one of the newly discovered medium to large scale turbidite-hosted gold deposits in Southeast Guizhou, South China. In this study, laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS) zircon U–Pb dating on the tuffaceous- and sandy-slates of Qingshuijiang Formation, Xiajiang Group, and gold-bearing quartz vein yielded similar age distributions, indicating that zircon grains in gold-bearing quartz vein originated from the surrounding tuffaceous- and sandy-slates. In addition, the youngest weighted mean ages of the zircon grains from the tuffaceous- and sandy-slates were 775 ± 13 Ma and 777 ± 16 Ma, respectively, displaying that the tuffaceous- and sandy-slates of the Qingshuijiang Formation were likely deposited in Neoproterozoic. Based on their major and trace element compositions, the tuffaceous- and sandy-slates were sourced from a felsic igneous provenance. The sandy slates have higher contents of Au (mostly ranging from 0.019 to 0.252 ppm), than those of the tuffaceous slates (mostly lower than 0.005 ppm). The δ34SV-CDT values of pyrite and arsenopyrite of the gold-bearing samples range from +8.12‰ to +9.99‰ and from +9.78 to +10.78‰, respectively, indicating that the sulfur source was from the metamorphic rocks. Together with the evidence of similar geochemical patterns between the tuffaceous- and sandy-slates and gold-bearing quartz, it is proposed that the gold might be mainly sourced from sandy slates. The metamorphic devolatilization, which was caused by the Caledonian orogeny (Xuefeng Orogenic Event), resulted in the formation of the ore-forming fluid. Gold was likely deposited in the fractures due to changes of the physico-chemical conditions, leading to the formation of the Chaoyangzhai gold deposit, and the large-scale gold mineralization in Southeast Guizhou.

Studi Awal Geologi di Daerah Beruang Kanan Kabupaten Gunung Mas Propinsi Kalimantan Tengah

PROMINE ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1-11
Author(s):  
Retno Anjarwati ◽  
Arifudin Idrus ◽  
Lucas Donny Setijadji
Keyword(s):  
Gold Mineralization ◽  
Volcanic Rocks ◽  
Gold Deposits ◽  
Central Kalimantan ◽  
Magmatic Arc ◽  
Tertiary Sediment ◽  
Copper Gold ◽  
Regional Tectonic ◽  
Mineralization Processes ◽  
High Yields

The regional tectonic conditions of the KSK Contract of Work are located in the mid-Tertiary magmatic arc (Carlile and Mitchell, 1994) which host a number of epithermal gold deposits (eg, Kelian, Indon, Muro) and significant prospects such as Muyup, Masupa Ria, Gunung Mas and Mirah. Copper-gold mineralization in the KSK Contract of Work is associated with a number of intrusions that have occupied the shallow-scale crust at the Mesozoic metamorphic intercellular junction to the south and continuously into the Lower Tertiary sediment toward the water. This intrusion is interpreted to be part of the Oligocene arc of Central Kalimantan (in Carlile and Mitchell 1994) Volcanic rocks and associated volcanoes are older than intrusions, possibly aged Cretaceous and exposed together with all three contacts (Carlile and Mitchell, 1994) some researchers contribute details about the geological and mineralogical background, and some papers for that are published for the Beruang Kanan region and beyond but no one can confirm the genesis type of the Beruang Kanan region The mineralization of the Beruang Kanan area is generally composed by high yields of epithermal sulphide mineralization. with Cu-Au mineralization This high epithermal sulphide deposition coats the upper part of the Cu-Au porphyry precipitate associated with mineralization processes that are generally controlled by the structure

scholarly journals Genesis of the Late Cretaceous Longquanzhan Gold Deposit in the Central Tan-Lu Fault Zone, Shandong Province, China: Constraints from Noble Gas and Sulfur Isotopes

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 250
Author(s):  
Chuanpeng Liu ◽  
Wenjie Shi ◽  
Junhao Wei ◽  
Huan Li ◽  
Aiping Feng ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Fault Zone ◽  
Late Cretaceous ◽  
Genetic Model ◽  
Gold Mineralization ◽  
Sulfur Isotopes ◽  
Noble Gas ◽  
Gold Deposits ◽  
Shandong Province ◽  
Magma Sources

The Longquanzhan deposit is one of the largest gold deposits in the Yi-Shu fault zone (central section of the Tan-Lu fault zone) in Shandong Province, China. It is an altered-rock type gold deposit in which ore bodies mainly occur at the contact zone between the overlying Cretaceous rocks and the underlying Neoarchean gneissic monzogranite. Shi et al. reported that this deposit formed at 96 ± 2 Ma using pyrite Rb–Sr dating method and represents a new gold mineralization event in the Shandong Province in 2014. In this paper, we present new He–Ar–S isotopic compositions to further decipher the sources of fluids responsible for the Longquanzhan gold mineralization. The results show that the δ34S values of pyrites vary between 0.9‰ and 4.4‰ with an average of 2.3‰. Inclusion-trapped fluids in ore sulfides have 3He/4He and 40Ar/36Ar ratios of 0.14–0.78 Ra and 482–1811, respectively. These isotopic data indicate that the ore fluids are derived from a magmatic source, which is dominated by crustal components with minor mantle contribution. Air-saturated water may be also involved in the hydrothermal system during the magmatic fluids ascending or at the shallow deposit site. We suggest that the crust-mantle mixing signature of the Longquanzhan gold deposit is genetically related to the Late Cretaceous lithospheric thinning along the Tan-Lu fault zone, which triggers constantly uplifting of the asthenosphere surface and persistent ascending of the isotherm plane to form the gold mineralization-related crustal level magma sources. This genetic model can be applied, to some extent, to explain the ore genesis of other deposits near or within the Tan-Lu fault belt.

scholarly journals Oxygen Fugacity and Volatile Content of Syntectonic Magmatism in the Neoarchean Abitibi Greenstone Belt, Superior Province, Canada

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 966
Author(s):  
Baptiste Madon ◽  
Lucie Mathieu ◽  
Jeffrey H. Marsh
Keyword(s):  
Oxygen Fugacity ◽  
Greenstone Belt ◽  
Inductively Coupled Plasma ◽  
Gold Mineralization ◽  
Gold Deposits ◽  
Hydrothermal Systems ◽  
Chemical Diversity ◽  
Temporal Association ◽  
Volatile Content ◽  
Abitibi Subprovince

Neoarchean syntectonic intrusions from the Chibougamau area, northeastern Abitibi Subprovince (greenstone belt), may be genetically related to intrusion related gold mineralization. These magmatic-hydrothermal systems share common features with orogenic gold deposits, such as spatial and temporal association with syntectonic magmatism. Genetic association with magmatism, however, remains controversial for many greenstone belt hosted Au deposits. To precisely identify the link between syntectonic magmas and gold mineralization in the Abitibi Subprovince, major and trace-element compositions of whole rock, zircon, apatite, and amphibole grains were measured for five intrusions in the Chibougamau area; the Anville, Saussure, Chevrillon, Opémisca, and Lac Line Plutons. The selected intrusions are representative of the chemical diversity of synvolcanic (TTG suite) and syntectonic (e.g., sanukitoid, alkaline intrusion) magmatism. Chemical data enable calculation of oxygen fugacity and volatile content, and these parameters were interpreted using data collected by electron microprobe and laser ablation-inductively coupled plasma-mass spectrometry. The zircon and apatite data and associated oxygen fugacity values in magma indicate that the youngest magmas are the most oxidized. Moreover, similar oxygen fugacity and high volatile content for both the Saussure Pluton and the mineralized Lac Line intrusion may indicate a possible prospective mineralized system associated with the syntectonic Saussure intrusion.

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