Gold Fields Research Articles

Utilising the 3D mineral system approach to identify the source of alluvial gold deposits in Ibala Town, Southwest Nigeria: an In-depth geological and geophysical exploration

ABSTRACT The Ibala gold field, discovered by artisanal miners in 2018, is located east of Ibala town in Osun State, southwest Nigeria. As older mines are depleted and abandoned, miners are now investigating the source of the deposits, believed to be auriferous quartz veins. This study uses the mineral system approach to trace the origin of the alluvial gold in the Ibala area. The research is conducted in three phases: first, a detailed analysis of the region’s structural patterns and rock distribution is undertaken to understand the area’s tectonic history. Next, a 3D conceptual model is created using an integrated geological and geophysical modeeling techinque to identify exploration targets and map the mineral system components. Finally, on-site verification is performed to validate the findings. The study reveals that the gold originates from auriferous shear zones characterized by high conductivity and chargeability geophysical signatures. These zones were formed by auriferous fluids released during the metamorphic devolatilization of deep volcanic rocks. As the fluids migrated through shear zones, they interacted with host rocks, precipitating gold alongside pyrite. When weathered, the gold-bearing material is transported via drainage channels, which miners now exploit. By using a mineral system approach, this research pinpoints the primary gold sources, supporting more efficient resource management and sustainable mining practices in the region.

Arc-shaped faults of the Golden Valley gold field of the Midlands greenstone belt in Zimbabwe and their role in localization of the ore mineralization

A detailed analysis of the geological and structural position of gold and tungsten deposits in the Golden Valley ore field of the Midlands greenstone belt has demonstrated that most of the gold deposits are controlled by arc-shaped faults that taken together form a semicircular structure with dimensions of 9×11 km. In addition, these arc-shaped faults apparently control the distribution of dikes of porphyry granites, that are associated with gold ore veins. Quartz-scheelite and gold-quartz-scheelite veins together form a second, less distinct, semicircular structure comparable in size to the first one. The highlighted structures were formed around isometric Late Archean granodiorite massifs, Lion Hill and Whitewaters, respectively, and are partially overlapped in space. The magnetic fi ld, also, reveals one additional arc-shaped fault and a series of linear faults. This arc-shaped fault, in conjunction with its associated branching veins of the Golden Valley and Patchway deposits, represents the so-called “horsetail” structure that is characteristic for gold deposits. This fault that is the most favorable structure for localization of gold ore veins, as well as the proposed junctions of arc-shaped and linear faults of radial and northwestern orientations, are considered as the most promising areas where geological prospecting is recommended.

Seismic imaging of deep‐seated gold deposit and host rocks through a reappraisal of legacy seismic data in the Fochville mining area, South Africa

AbstractReappraisal of legacy reflection seismic data has shown to deliver value in mineral exploration, particularly in brownfield settings. In this work, we demonstrate how the reappraisal and processing of legacy reflection seismic data can be advantageous in the mineral exploration industry. We use today's standard seismic processing tools to improve the imaging of deep and complex geological structures that host mineral deposits. The recovered and processed 25.3 km long legacy seismic profile in this study was acquired in 1983 by the Gold Division of Anglo‐American as part of the Witwatersrand Gold Fields exploration program. This study aims to improve the imaging of the Ventersdorp Contact Reef gold‐bearing horizon (termed reef), a world‐class gold deposit (2 m thick) situated at depths between ∼2400 and ∼4100 m below the ground surface near South Deep Gold Mine in Fochville, South Africa. The final processing results from the pre‐stack time and phase‐shift migration approaches clearly reveal a dipping reflection associated with the gold‐bearing horizon and major steeply dipping faults that crosscut and displace the deposit. The final results are integrated with borehole information, 1D synthetic modelling and aeromagnetic data to constrain the structural interpretation. In particular, 1D synthetic simulation and borehole data constrain the depth position of the gold deposit. The magnetic data provides additional constraints on the complex faulted blocks of the host rocks such as the intrusions that may have a direct impact on ore resources and evaluation. The mining companies, such as South Deep Gold Mine, operating closer to the seismic profiles can use this new structural information to update the current geological models and improve future mine planning and designs, thus providing some insight into the prospectivity of unmined ground.

40Ar/39Ar Dating of Hydrothermal Processes in Large Gold Deposits of the Kochkar Anticlinorium (South Urals, Russia)

The age restrictions for productive mineral associations of the two largest gold deposits of the Southern Urals—Svetlinsk and Kochkar, which are located in the East Uralian megazone—are discussed. The 40Ar/39Ar dating method was performed for the first time for potassium-containing hydrothermal minerals (micas and amphiboles) from the ore veins and ore-host alteration, as well as from marbles. The age estimates obtained are in the range of 290–276 Ma; the weighted average value for the Svetlinsk deposit is 276 ± 2 Ma; for the Kochkar field, 284 ± 2 Ma. It is supposed that the studied mineral assemblages of the Svetlinsk and Kochkar deposits were formed in the beginning of the postcollision stage corresponding to the tectonic relaxation regime. Age of hydrothermal mineral formation in the gold fields of the Kochkar anticlinorium are consistent with the time of post-tectonic plutonic activity, which was expressed in the Middle–Southern Urals in large-scale granitization (~300 Ma). The ore-bearing alteration of a femic profile (of the same age for two deposits), which are most likely basificates, are near-synchronous with the granitization.

Evaluation of potentially toxic metals in tailings from Busia gold mine fields of eastern Uganda

Busia Gold mines in eastern Uganda generate significant wastes that contribute to environmental and health challenges in the region. This study assessed the extent of 9 potentially toxic metals (PTMs) present in Busia gold mine tailings. The study also evaluated environmental risks for each of the PTMs, using contamination indices. The indices were: index of geo accumulation (Igeo); potential ecological risk index (RI); contamination factor (CF); pollution load index (PLI) and ecological risk factor (ERI). Tailing samples were collected at two distinct depths; surface (0–30 cm) and deep (30–60 cm) from four sites. The samples were analyzed using an Atomic Absorption Spectrometry (AAS). The Igeo results showed that As and Hg recorded extreme pollution levels (Igeo >5) in all 4 sites. The other seven PTMs in all the sites were classified between heavily polluted to unpolluted categories. CF results revealed extreme contamination for Hg at site-A and As at site-M with moderate contamination of Ni, Zn, and Co at sites-C and B. RI findings showed that all the sites recorded RI > 600, with the highest (RI = 80, 407) at site-A, followed by site-C (RI = 74, 536). All the sites had a high level of ecological impact with greater potential for environmental risks in the area. In the case of PLI, all the sites were classified as polluted sites (PLI > 1). Sites-M and C recorded the highest (PLI = 12), followed by sites-B and A, with PLIs of 11 and 9, respectively. ERI findings for all the sites showed significant Hg, As, and Cd contamination, (ERI >320). Site-A recorded the highest Hg contamination (ERI = 78, 825). Site-M recorded elevated levels of As and Cd, with ERI of 1, 323, and 399, respectively. Pb at site-M posed considerable potential ecological risk with an ERI of 108, while Zn, Cu, Co, Ni, and Cr presented low ecological risk across all sites with ERI˂ 40. There is, therefore, need to properly manage tailings in Busia gold fields to minimize ecological contamination to avoid impacts on human, animal, and plant health.

Integrated geophysical Investigation for gold mineralization potential over southern parts of Kebbi state and its Environs, northwestern Nigeria

The potential zones of gold mineralization were identified in this study using aeromagnetic and aero-radiometric methods. The Nigerian Geological Survey Agency (NGSA) provided half-degree airborne magnetic and radiometric datasets covering the southern part of Kebbi State. Magnetic data were subjected to first vertical derivative (1VD), total gradient amplitude (TGA), total horizontal derivative (THD), source edge detection (SED), center for exploration targeting (CET), Euler deconvolution (ED) and source parameter imaging (SPI) to identify favourable structures to gold mineralization. Aero-radiometric data delineation of the region of hydrothermal alteration zones through the K/eTh ratio, K_deviation, F_parameters, and Ternary image analyses were successful. The results of the magnetic data techniques revealed the regions of major structures/or lineaments with gold mineralization attributes, trending in the NE to SW directions and the SE to NE parts of the study area. The depth to the structures of the magnetic source hosting gold mineralization was less than 5 m using algorithm ED and SPI techniques. Normalized radiometric data showed the area of anomalously high and moderate hydrothermal altered zones. The region's designation as a gold field is supported by major fault lines observed on the 1VD, a sequence of bristle fractures from the CET analysis, and high values of K_deviation and F_parameter, all of which are were visible on the Ternary images. The integrated results revealed zones of major structures and hydrothermal regions of gold fields at Agwara, Western Magama, Rijau, Fakai, Bukkuyum, and Borgu in the SE of the study area.

Integrating multispectral remote sensing and geological investigation for gold prospecting in the Borongo-Mborguene gold field, eastern Cameroon

Multispectral remote sensing data has great promise for mineral prospecting via regional-scale mapping of alteration zones and geological structures, once the method is calibrated using in-situ geological observations. The Borongo-Mborguene area, located in eastern Cameroon at the transition from sub-tropical to arid climates, hosts several alluvial gold deposits. In this investigation, maps developed by processing of Landsat-8 OLI images, ASTER satellite images, and SRTM DEM data were compared to results of a comprehensive field survey to locate zones of hydrothermal alteration and regional structural lineaments, and to verify the association of these features with gold mineralization. Specific Landsat-8 and ASTER band ratios, as well as principal component analysis of the multispectral images, were selected to isolate spectral signals that characterize particular groups of alteration minerals, such as clays, hydrated carbonates, hydrated sulphates, iron oxides, and iron hydroxides. Lineaments and their preferred orientations were extracted by filtering of the digital elevation data. A fuzzy logic approach was subsequently applied to the ensemble of resulting maps to highlight five areas of concentrated hydrothermal alteration and structural complexity as potential gold prospects (Mborguene, Boutila, Nandoungue, Borongo and Ouaden villages). Petrographic study of samples collected from the remotely-identified alteration zones revealed a hydrothermal ore assemblage of gold, galena, pyrite and hematite in mineralized quartz veins. Structural control of the alteration zones in the Borongo-Mborguene gold field was confirmed by field mapping along a shear zone. Hence, our petrographic and field studies indicate that the multispectral remote sensing data and data processing methods developed herein are appropriate for mineral exploration in remote sub-tropical areas of Africa. More generally, the computationally efficient and simple procedure developed here should yield accurate preliminary maps of the spatial distribution of hydrothermal halos and related mineral deposits in challenging mixed-type vegetated terrain around the globe.

Green Product Awareness Effect On Purchase Decision Of College Students In Kolar Gold Fields.

Green Product Awareness Effect On Purchase Decision Of College Students In Kolar Gold Fields.

Bioaccumulation of Pb (Lead) in the Muscles of Danio rerio and its Effect on the Anti-oxidant Enzyme Catalase in the Mining Vicinity of Kolar Gold Fields

Bioaccumulation of Pb (Lead) in the Muscles of Danio rerio and its Effect on the Anti-oxidant Enzyme Catalase in the Mining Vicinity of Kolar Gold Fields

IJCM_313A: Assessment of the health-related quality of life among ex-mine workers of Kolar gold fields, Kolar, Karnataka

Background: Karnataka ranks third with regards the number of mines in India and Kolar, at one time, had the world’s deepest and most productive gold mines. Miners are exposed to hazardous agents like silica, coal and asbestos which adversely impact health. Objectives: To assess the health-related quality of life (HRQL) of ex-mine workers at Kolar Gold Fields (KGF), Kolar, Karnataka. Methodology: An analytical cross-sectional study was conducted among 240 (estimated 196 with 50% prevalence) male ex-mine workers of KGF. An interview scheduled, consisting of socio-demographic factors, COPD Assessment Test (CAT) and Kings Brief Interstitial Lung Disease (KBILD) was administered. Lower CAT score and higher KBILD score indicate better HRQOL. Results: The mean age of the participants was 69.71±8.56 years. Participants were previously involved in drilling (113-47%) and blasting (127-53%) activities in the mines, with a mean of 14.68±6.46 years of work exposure. The mean scores for CAT and KBILD were 15.80±7.42 and 52.83±8.77 respectively. Based on CAT scores, half (51%) of participants reported medium impact of COPD on their health. Participants with longer duration of work experience had significantly higher CAT scores [OR-36.64 (12.14-110.6)]. KBILD score was significantly higher among those who worked in blasting (M=113. SD=52.14) than those involved in drilling (M=127, SD=53.43). Lower duration of work was significantly associated with higher KBILD scores (p<0.01). Adjusted logistic regression showed higher education and income had a positive impact on HRQL and an increase in age and longer work experience adversely affected HRQL. Conclusion: This study reveals the hazardous impact of drilling and blasting work on the health-related quality of life of ex-mine workers. Understanding this, for the future, it is important to educate workers, improve financial stability and minimize hazard exposure to enhance the quality of life of miners amidst the challenges of mining operations.

In Situ Trace Element and S-Pb Isotope Study of Pyrite from the Denggezhuang Gold Deposit in the Jiaodong Peninsula—Insights into the Occurrence of Gold and the Source of Ore-Forming Materials

The Jiaodong gold province is one of the most important gold fields globally and the largest in China. The Denggezhuang gold deposit is situated in the eastern portion of the Muping metallogenic belt, within the Jiaodong gold province. Despite many recent investigations, detailed mineralogical studies, particularly on auriferous minerals such as pyrite, are lacking. Therefore, further constraints on the occurrence mode and source of gold are necessary for this deposit. This study employed in situ laser ablation (multi-collector) inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) trace element and sulfur-lead isotopic analyses on pyrite at different stages. The aim was to reveal the occurrence status of various trace elements within Denggezhuang pyrite and to trace the complete evolution process of multi-stage fluids at Denggezhuang, elucidating the sources of gold mineralization. Four generations of pyrite in chronological order, Py-1, Py-2a, Py-2b, and Py-3, were identified via petrographic and backscattered electron (BSE) image analyses. Using in situ LA-MC-ICP-MS, we found that Co and Ni are most abundant in Py-1, while Py-2b is rich in As, Au, Ag, Pb, and Zn, reflecting the evolution of the mineralizing fluids in different mineralization stages. Py-2b contains a significant amount of invisible lattice gold, which migrates and precipitates within fluids rich in As. The in situ LA-MC-ICP-MS S-Pb isotopic analysis of pyrite indicates a relatively consistent source of ore-forming materials across different stages. Additionally, the S-Pb isotope characteristics resemble those of widely distributed coeval mafic dikes. Therefore, we propose that a water-rich, fertile, and deep-seated mafic magmatic system might have provided fluids, materials, and heat for mineralization.

Three-dimensional modeling and geostatistical structural analysis for ore deposit prospecting trend and wisdom mining: a case study in the Jiaoxibei gold field, China

The orientation of deep-seated orebodies was observed shifted from the northwest to north at the Xincheng deposit in the Jiaoxibei gold field during the mining operations. To make informed decisions, understanding the geological factors influencing this directional change is crucial for mining engineers. Prior research suggested that the ore-controlling fault morphology might correlate with the orebody positions and the thickness of alteration zones. Hence, the morphology of fault structures emerges as a key point in this work. First, we constructed a three-dimensional (3D) fault surface model. A large fault framework was interpreted using gravity–magnetic–electrical geophysical datasets, and then, the local details of the fault surfaces were characterized using an interpolation method based on the drillhole fault gouge data. Subsequently, we statistically assessed the spatial association between fault morphology and orebody positioning using the standardized C-values method and demarcated the ore-controlling structures on fault surfaces using quantitative indicators. The indicators of fault dips, fault azimuths, and the second-order trend residuals of fault surfaces represented the fault morphology. The drillhole grade data (Σsampling grade * sampling length) were used to describe the scale of mineralization zones, and the cumulative thickness of the pyrite–sericite altered rocks indicated the intensity of alteration zones. Finally, a geostatistical structural analysis was used to depict the mineralization orientation at different locations. Through these methods, we aim to propose a potential pattern of how ore-controlling fault morphology spatially influences the positions and orientations of orebodies. This comprehensive approach offers valuable insights into exploring deep-seated mineralization at the Xincheng deposit, aiding in a better understanding of the deposit’s geological dynamics for future mining endeavors.

Sulphur in apatite: a potential monitor of the magmatic redox state in the world-class gold fields of the North China Craton

ABSTRACT The redox condition, a key parameter of mineralization, is one of the most difficult parameters to constrain precisely. Here we employ electron probe and X-ray photoelectron spectroscopy (XPS) to analyse sulphur (S) in apatite grains from five granitoid plutons that are differentially related to gold mineralization in the world-class gold fields of Jiaodong, Xiaoqinling, and Wutai-Hengshan within the North China Craton (NCC) to constrain the redox condition of melt. The results show increasing order of the apatite S content and S6+/ΣS ratios in the Linglong (only spatially close the Jiaodong gold deposits), Sunzhuang (related with the Yixingzhai gold deposits), Huashan (weakly related with the Xiaoqinling gold deposits), Wenyu (closely related with the Xiaoqinling gold deposits) and Guojialing plutons (closely related with the world-class Jiaodong gold deposits), indicating that the oxidation state increased from the Linglong pluton to the Guojialing pluton. The S concentrations of Guojialing, Wenyu, Huashan and Sunzhuang plutons, are estimated using previous methods are, 120–208 ppm, 107–138 ppm, 72–77 ppm and 10–74 ppm, respectively. Combined with the regional differences in gold mineralization in the North China Craton, the gradual increase in mineralization scale is consistent with the trend of increasing oxidation state in the granitoid plutons from Wutai-Hengshan to Xiaoqinling to Jiaodong goldfields, thus also underpinning the contribution of Mesozoic granites to gold mineralization in the North China Craton through providing the thermal energy and medium for the activation and migration of ore-forming fluids.

New data on the geological structure and zonality of the Vorontsovka gold field in the Northern Urals

Spatial distribution of gold, copper, and iron ore deposits in the Northern Urals with the largest Turya-Auerbakh ore region is controlled by north-west trending linear zones of a probably fault nature. The influence has been demonstrated of regional factors (including the tectonic, magmatic, and geochemical ones) favoring formation of the large Au-As-Sb-Hg-Tl Vorontsovka deposit located within a volcanogenicsedimentary, substantially carbonate rock sequence. Closely spaced swarms of Devonian pre-ore and Carboniferous post-ore mafic dykes have been identified within the deposit. The primary geochemical halos of the Vorontsovka deposit have a multielement composition and, coupled with the ores, form a thick ore-halo zone confined to the gentle tectonic contact of sandstone-siltstone and limestone units. The main halo-forming elements are zonally distributed in the section. The footwall side of the gold deposit (rear zone) is dominated by Zn, Cd, Cu, Pb, Ag, and Bi; the axial zone, by Sb, Hg, Tl, and As; and the hanging side (frontal zone), by
 As, Zn, Hg, Pb, Ag, (Cu). In the east (closer to the Auerbakh granitoid massif), Ag, Zn, Pb, Mn, Y, Mo, and W relatively accumulate, while in the west (most remotely from the intrusive), Sb, Ba, As, Hg, Co, Ni, and Sn dominate. The 40Ar/39Ar age of ~391.1 million years, obtained for hydromica of the gold-arsenic ores, corresponds to the period of emplacement of granodiorite of the final Auerbakh massif intrusive phase. The conclusion is made on the crucial magmatic contribution to the formation of gold ores of the deposit.

Sustaining the frontier: a Chinese merchant on the settlement frontier of colonial Far North Queensland

ABSTRACT The fortuitus access to long lost manifests of the Cooktown to Laura railway provides a unique insight into the operations of Chinese merchants serving Far North Queensland gold field communities during the colonial era which hitherto have received scant attention. Whilst the existence of Chinese merchants throughout Far North Queensland during colonial times, commencing with the Palmer River goldrush of 1873 has been documented, very little has been known about the specific details of their operations. The details of the manifests, complimented with other archival records, provide a unique picture of a sophisticated supply network drawing from local, intercolonial and overseas sources. It also highlights the dual flow of goods and services that sustained the operations of these frontier merchants. The paper will case study a pioneers Chinese Merchant of this era who had business interests in Cooktown, Laura and Maytown.

‘A long want’: an archival exploration of scurvy in the Otago goldfields of New Zealand

ABSTRACT In this paper we test a long-held assumption regarding Otago, New Zealand, goldfields life and death- that scurvy was a ubiquitous and persistent cause of misery and death among the goldminers. We will also explore a parallel argument that the Chinese market gardeners played a large role in stamping out the disease in the goldfields. Through the interrogation of various archival medical primary sources, we show that scurvy was indeed a terrible scourge in the Otago goldfields, but only during the initial rushes into new regions. We also argue that while Chinese market gardeners undoubtedly contributed to a more nutritious and varied diet for European miners and settlers, scurvy had already markedly reduced in frequency by the time of their arrival in the gold fields. Patient-oriented accounts of scurvy in the gold demonstrate the clinical and functional cost of scurvy in during the initial gold rushes of Otago. Furthermore, individual stories of previously anonymous patients found locked in these archival sources demonstrate the importance of re-humanising the past to understand the biological and social context of these frontier times.

Effect of praseodymium coating on electron emission from a nanoscale gold field emitter array

Although field emission devices are inherently robust to high temperature and radiation environments as well as have high switching speeds, their development has been hindered by high voltages that are typically required for their operation. In this work, we investigate the effect of thin-film praseodymium (Pr) coating on the emission characteristics of a lateral gold (Au) field emitter array. Because Pr has a significantly lower work function than Au, it is expected to increase the field emission measured current. Pr is deposited onto the device via thermal angled evaporation in a custom-built vacuum chamber with in situ electrical characterization capability. Our experiments demonstrate that a 10 nm-thick Pr layer reduces the turn-on voltage by almost half compared to the noncoated Au structure. These results are promising for the development of power-efficient, low voltage field emission electronics.

Using association rules analysis to determine favorable mineralization sites in the Jiaojia gold belt, Jiaodong Peninsula, East China

Mesozoic orogenic gold deposits in the Jiaojia goldfield, Eastern China show the features of regular mineralization spatial distribution and have long been captivated the attention of geologists. This study integrates 3D modeling, model space analysis, and association rule analysis to extract the relationship between structural deformation and gold mineralization. The Apriori algorithm with spatial constraints is used to quantify the favorable mineralization sites in the Jiaojia gold field using different combinations of ore-controlling indicators. The first favorable mineralization site has a 44% probability of mineralization and is primarily located in segments of the fault footwall within 25 m of the fault buffer where the transition from steep to gentle occurs (∼1–24). Its uniform distribution indicates that the ore-bearing space near the main fault plane is relatively wide, and hydrothermal diffusion is relatively uniform. Site No. 2 has a 45% probability of mineralization and is located in convex segments (6–35 m) between 25 and 55 m of the fault footwall. The equidistant zonal distribution in this area indicates that secondary faults and fractures have facilitated the migration of hydrothermal fluids, resulting in the formation of extensive ore-bearing spaces. Site No. 3 sited in convex segments (∼0–6 m) distal to the fault footwall (∼55–515 m) of the fault buffer where the dip is gentle (∼30°–35°). The binary structure of differing dips formed by the intersection of steeply dipping orebodies and the slowly dipping orebodies in the central and southern parts of the Nanlü-Xinmu deposit exhibit the complex channel away from the main fault. In this study, the correlation between ore-controlling factors and mineralization in Jiaojia fold field is quantitatively expressed as favorable mineralization sites in the form of association rules, it would contribute to a deeper understanding of the underlying mechanisms governing the formation of structure-controlled orogenic gold deposits in the Jiaojia goldfield.

Biogeochemical networks in the abandoned historical gold mines affecting mobilization and transport of arsenic in Kolar

Enormous water-logging in ancient abandoned mining shafts of Kolar Gold Fields (KGFs), has largely induced the leaching of sulfide-rich gold minerals contaminating the aquifer system with hazardous elements. Transport of these contaminant has posed threat to the health of the urban population of Kolar township. A detailed survey of borewells, covering radius of 10 km of the KGF was carried out during pre and post-monsoon seasons and various parameters were assessed. Almost 80% of the water samples exceeded the regulatory limits of potable water criteria with excess arsenic (As; 12–127 μg/L), fluoride (F; <0.005 μg/L), dissolved salts (>500 mg/L). Water Quality Index (WQI) was used to understand the overall urban groundwater quality. At the centre of sampling circle core, mineral dissolution was found to be the function of pH, induced by acidophilic sulfur oxidizing bacteria . Modelling of predicted microbial metabolic pathways in metagenomics libraries using PICRUSt, indicated complex functional networks. High expression of siderophore proteins (> 2 cm halo in the chrome azurol test) caused Fe-sequestration, secondary Fe-mineral formation and subsequent release of As. Sulfide bearing Au-rich minerals (Arsenopyrite, Scorodite, Jarosite) were bio-weathered leading to release of H3AsO3+ at low pH, resulted in groundwater composition of Ca–HCO3 type and Ca–Na–HCO3 or Ca–Mg–Cl type.

Thị trường vàng sau Nghị định 24 và một số khuyến nghị

Gold plays an instrumental role in the world economy in general and Vietnam in particular, even though it is no longer a currency. In an attempt to stabilize the fluctuated gold market in the early 2000s, the Vietnamese government issued numerous documents, including (i) regulations on the termination of the gold trading floor and domestic gold trading accounts, (ii) regulations on the termination of gold mobilizing and lending activities of credit institutions, (iii) regulations on the management of gold business activities, (iv) regulations on the sanctions for administrative violations in the field of foreign exchange and gold. Decree 24/2012/ND-CP, regulations on the management of gold business activities, is supposed to be the most comprehensive document, which contributes to the restructuring and reorganization of the entire Vietnamese gold market under the control of the State Bank. This paper analyzes the context of Decree 24 issuance and evaluates the outcomes of Decree 24 application based on the following criteria: (i) restructure the gold market and put a restraint on the “goldalized” economy, (ii) stabilize the gold price and reduce the impacts of gold price on the macro-economy, in turn, proposing suggestions regarding the gold market management in the current context.