Prediction of Hidden Ore Bodies using Integrated Geology, Source of Fluids and Stratagem EH4 Geophysical Survey in Kuoerzhenkuola Gold Deposit in Xinjiang, China

Magnetic and gravimetric surveys were conducted over an area of approximately 1400 square miles in the bauxite district of central Arkansas. The primary purpose of these surveys was to discover any possible buried and hitherto unknown syenite masses favorable for the occurrence of bauxite and to determine the approximate position of the buried flanks of the known syenite masses which might offer conditions favorable for the discovery of new ore bodies. These surveys indicated that the various syenite outcrops are domes or bosses on a large batholith and that other similar domes occur on the batholith but do not outcrop. Drilling on the local geophysical anomalies proved the presence of 10 buried domes, but only 2 were found to project above the upper surface of the Midway clays, a requisite of conditions favorable for the occurrence of bauxite ore bodies. The geophysical data indicated the approximate configuration of the buried flanks of the known syenite outcrops, and the portions of these flanks that project above the Midway have now been outlined more accurately by drilling. The geophysical surveys have produced evidence permitting the elimination of a large area as unfavorable for the occurrence of bauxite. Magnetic surveys extending along the Midway‐Wilcox contact from Gurdon in Clark County on the southwest to Searcy in White County on the northeast have proved the improbability of the existence of other syenite masses similar to those found in Pulaski and Saline Counties. A detailed magnetic survey of the Magnet Cove area in Hot Spring County has proved that the syenite mass exposed in that locality is an isolated intrusion and entirely unrelated to those of Pulaski and Saline Counties. This syenite mass does not occur under conditions believed to be favorable for the occurrence of bauxite.

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Fluid Inclusions and their Geological Significance of Huajian Gold Deposit, Hebei Province, China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.277 ◽

2014 ◽

Vol 962-965 ◽

pp. 277-281

Author(s):

Cheng Long Shi ◽

Yang Song ◽

Jian Zhong Hu

Keyword(s):

Gold Deposit ◽

North China ◽

Gold Mineralization ◽

Hebei Province ◽

North China Block ◽

Quartz Veins ◽

Low Salinity ◽

The North ◽

Ore Bodies ◽

Metallogenic Belt

The Huajian gold deposit is located in the metallogenic belt of the northern part of the North China block. This deposit's ore bodies are mainly hosted in metamorphosed Neoarchean and Mesoproterozoic sedimentary rocks, of which Mesozoic volcano-intrusive complexes are closely associated with the Gold mineralization. The FIs of the Huajian deposit are primarily aqueous FIs with minor gas FIs. The pure gas or liquid FIs are very few. The ore-forming fluids were characterised by moderate–low temperature, low salinity and high oxygen fugacity and belonged to an H2O–NaCl ± CO2system. The FIs in quartz veins primarily developed in temperature intervals of 202–380°C, 191–407°C and 170–307°C., corresponding to salinities of 3.85wt.% to 11.23 wt.%, 3.69wt.% to 10.99 wt.% and 2.06wt.% to 17 wt.% NaCl eq.., respectively. The trapping pressures of the FIs from high temperature fluids in the quartz veins are 10-90 MPa, corresponding to depths of 1.0–10 km, assuming a density of the overlying rocks of 0.54 g/cm3–0.98 g/cm3. Multiple stages of phase separation or immiscibility of ore-forming fluid was critical for the formation of the Huajian deposit.

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The Saidu Gold Deposit of Southern Altai, China: Mineralizing Stages and Ore-Forming Fluids Evolution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.215 ◽

2013 ◽

Vol 734-737 ◽

pp. 215-218

Author(s):

Guo Rui Zhang ◽

Jiu Hua Xu ◽

Li Hua Shan ◽

Hui Zhang ◽

Xiao Feng Wei

Keyword(s):

Gold Deposit ◽

Gold Mineralization ◽

Early Stage ◽

Shear Zones ◽

Ductile Shear Zone ◽

Tectonic Zone ◽

Low Salinity ◽

Ore Bodies ◽

Evolution Characteristics ◽

Homogenization Temperatures

The Saidu gold deposit is located in the northwest part of Ertix Tectonic Zone in Xinjiang. The ore bodies occur in altered mylonite zones within the Mar-kakol giant fault zone and are controlled by the ductile shear zone. The structural-metallogenic fluids of the early stage are characterized by mesothermal-hydrothermal CO2-N2-rich fluids, with homogenization temperatures of fluid inclusions being 252~408°C. The tectonic-metallogenic fluids at the middle stage are characterized by CO2-H2O fluids, with homogenization temperatures being 203~326°C. The fluids at the late stage were epithermal-mesothermal low salinity aqueous solutions, with homogenization temperatures being 120~221°C. The main gold mineralization was related to the post-orogenic extension environment, with the evolution characteristics corresponding to the evolution of shear zones.

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The Orogenic Crixás Gold Deposit, Goiás, Brazil: A Review and New Constraints on the Structural Control of Ore Bodies

Minerals ◽

10.3390/min11101050 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1050

Author(s):

Stanislav Ulrich ◽

Steffen Hageman ◽

Juliana Charão Marques ◽

Frederico Lana A. R. Figueiredo ◽

João E. F. Ramires ◽

...

Keyword(s):

Gold Deposit ◽

Structural Control ◽

Gold Mineralization ◽

Current Knowledge ◽

Current Model ◽

Regional Scale ◽

Structural Data ◽

Stratigraphic Sequence ◽

Structural Framework ◽

Ore Bodies

A review of the current knowledge of lithostratigraphy, geochronology, mineralogy, alteration, fluid chemistry and structural data is provided in order to discuss the main controls on mineralization in the Crixás gold deposit and the existing structural framework and evolution. Gold mineralization at Crixás represents orogenic upper mesothermal to lower hypothermal types developed within the overturned Paleoproterozoic (Rhyacian) stratigraphic sequence. The structural data indicates that upright folding of the stratigraphy and formation of a distinct S1 foliation characterizes D1 deformation. This controls the formation of laminated quartz veins, precipitation of Au-rich sulfides, and the development of NW trending orebodies. Localized F2 folding of D1 structures and strong L2 stretching lineations characterizes the D2 event. This localized F2 folding created oreshoots trending W-WNW within distinct orebodies. The D2 deformation is associated with the precipitation of native Au. The ‘bulk plunge’ of these orebodies is a combination of both plunges defined by D1 and D2 deformation events. A critical assessment of lithostratigraphic and structural data reveal two possible tectonic scenarios operating during the Paleoproterozoic. The first possible tectonic scenario considers sagduction and the development of a regional-scale synclinorium, followed by tilting and localized folding of D1 structures. The second scenario, which is similar to the current model, considers accretion producing a synclinorium, followed by thrusting. Based on the current knowledge, both models are considered to be permissible and a series of focused research studies are proposed to test both the current and the new tectonic models.

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Justification of safe and effective working conditions for pit reserves of “Pioner” gold deposit

E3S Web of Conferences ◽

10.1051/e3sconf/20185602013 ◽

2018 ◽

Vol 56 ◽

pp. 02013 ◽

Cited By ~ 1

Author(s):

Marina Potapchuk ◽

Gennady Kursakin ◽

Viktor Krukov ◽

Mikhail Lomov

Keyword(s):

Gold Deposit ◽

Working Conditions ◽

Physical And Mechanical Properties ◽

Rock Massif ◽

Ore Bodies ◽

Minimum Margin ◽

Rational Order ◽

Working Out ◽

Underground Method ◽

Safe Working

Further prospects for the development of “Pioner” gold deposit are associated with the development of deep-seated ore bodies by an underground method. When assessing the bump hazard of proposed technological solutions for stripping and working out the pit reserves of the deposit and substantiating the safe working conditions, some comprehensive studies were carried out, including an analysis of the geological and geomechanical conditions of deposit's development, detailed study of the physical and mechanical properties of rocks and ores, investigation of the fracture tectonics of the deposit and stress and strain state of the rock massif of the deposit. The performed modeling of the geomechanical processes of the rock massif with the use of numerical methods made it possible to identify the safe parameters of the guarding safety pillars under the pit bottom, and also to identify areas and elements of rock structures characterized by a minimum margin of stability according to the criteria of the acting maximum compressive and tangential stresses after complete mining of ore bodies. Recommendations were developed on the rational order of mining of ore bodies and on effective ways to protect and maintain mine workings.

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Rb-Sr Isotopic Geochronology and Geological Implications of Dongfeng Gold Deposit in Jiaodong Area

Earth Sciences Research Journal ◽

10.15446/esrj.v20n1.55178 ◽

2016 ◽

Vol 20 (1) ◽

pp. 1-7

Author(s):

Wang Zongyong ◽

Han Xin ◽

LV Guxian ◽

Zhang Xunyu ◽

Zhang Yingchun ◽

...

Keyword(s):

Gold Deposit ◽

Isotopic Analysis ◽

Northwestern Part ◽

Mineralization Process ◽

Geological Process ◽

Ore Bodies ◽

Isotopic Geochronology ◽

Mesozoic Granite ◽

Set Up ◽

The Relationship

The superlarge Dongfeng gold deposit is located in the Potouqing faults-alteration belt of the eastern part of the ‘Zhao-Lai-gold ore belt’, which belongs to the northwestern part of the Jiaodong area. Tectonically, ore bodies are controlled by faults and gold mainly occurs in the pyrite and polymetallic sulfide-bearing quartz vein. In this paper, Rb–Sr isotopic analysis is carried out with the beresite, which formed by hydrothermal metasomatism, and the Rb–Sr isochron age is 125.5±6.7Ma, indicating this deposit set up in the early Cretaceous of the late Yanshanian. Based on the relationship between the Dongfeng gold deposit and the Mesozoic granite, it is suggested that the formation of the gold deposit is a complex geological process of gradual enrichment and precipitation of the ore-forming elements. The initial 87Sr/86Sr ratio of the beresite is 0.711502±0.000069, which indicates the ore-forming materials mainly come from the crust. Combined with the complex mineralization process of the Dongfeng gold deposit and the reported H-O isotopic data, it is suggested that the ore-forming materials are mainly derived from the crust with some mantle materials, while the ore-forming fluids are originated primarily from magmatic hydrothermal and mantle with some precipitate water.

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«PIONEER» GOLD ORE DEPOSIT: HISTORY OF DISCOVERY, GEOLOGICAL STRUCTURE AND ORE COMPOSITION

10.22250/jasu.10 ◽

2020 ◽

pp. 58-63

Author(s):

VITALY ALEKSEEVICH STEPANOV ◽

Keyword(s):

Gold Deposit ◽

Late Jurassic ◽

Geological Structure ◽

Sulfide Mineralization ◽

Ore Deposit ◽

Terrigenous Rocks ◽

Ore Bodies ◽

History Of ◽

Gold Ore Deposit ◽

Gold Sulfide

Brief information about the history of the discovery of the large Pioner gold deposit in the Amur province is given. The main features of the geological structure of the deposit, located at the contact of the multiphase granitoid intrusion of the Early Cretaceous age and terrigenous rocks of the Middle-Late Jurassic, are shown. Ore bodies are linear stockworks of silicified and carbonated rocks with gold sulfide mineralization. Gold is both free in the form of large, small and micron-sized particles, and in bound form in pyrite. In common ores, its fineness ranges from 650 to 880 units, in rich ores it rises to 870 - 915‰.

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Application and Significance of Geological, Geochemical, and Geophysical Methods in the Nanpo Gold Field in Laos

Minerals ◽

10.3390/min12010096 ◽

2022 ◽

Vol 12 (1) ◽

pp. 96

Author(s):

Jie Gan ◽

Hui Li ◽

Zhengwei He ◽

Yu Gan ◽

Junqing Mu ◽

...

Keyword(s):

Gold Deposit ◽

Large Scale ◽

Geophysical Methods ◽

Mineral Resources ◽

Mining Area ◽

Gold Deposits ◽

Rock Body ◽

Metallogenic Province ◽

Geochemical Anomalies ◽

Ore Bodies

As the main part of the Indosinian metallogenic province in the eastern part of the Tethys metallogenic domain, Southeast Asia has experienced multiple stages of tectonic magnetic activities accompanied by the formation of rich mineral resources. However, due to the undeveloped economy, low degree of geological work, dense vegetation cover, and lack of obvious prospecting marks, traditional geological prospecting work in the area is not optimal. Consequently, the combination of high-precision geophysics and geochemistry has become an important method of looking for ore bodies deep underground in this area. The Nanpo gold deposit is a hydrothermal gold deposit that occurs in the Indosinian felsic volcanic rock body, and its mineralization is closely related to felsic magmatism. This study carried out comprehensive geophysical and geochemical exploration methods of soil geochemical survey, induced polarization (IP) survey, and audio-frequency magnetotelluric (AMT) survey. Based on the characteristics of geophysical and geochemical anomalies, geological inference, and interpretation, the integrated geophysical and geochemical prospecting criteria of the ore area have been determined: The large-scale and overlapping Au-Ag-Cu anomaly area in the host felsic magmatic rocks (mainly diorite, monzodiorite and granodiorite) is a favorable metallogenic area. Two anomalies, P1–H1 and P3–H6, with the best metallogenetic conditions and the deepest extensions of the known ore bodies, were further selected as engineering verification targets. After the study of the drill core, gold (mineralized) bodies consistent with the anomalies were found, indicating that the combined method is suitable for the exploration of mineral resources in this area, and the prospecting effect is good. At the same time, the metallogenic prediction shows that the deep part of the mining area still has great metallogenic prospects and prospecting potential. The characteristics of geophysical and geochemical anomalies and prospecting experience in the study area can provide references for the prospecting of hydrothermal gold deposits in the Luang Prabang–Loei structural belt.

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Metal-Bearing Nanoparticles Observed in Soils and Fault Gouges over the Shenjiayao Gold Deposit and Their Significance

Minerals ◽

10.3390/min9070414 ◽

2019 ◽

Vol 9 (7) ◽

pp. 414 ◽

Cited By ~ 2

Author(s):

Bimin Zhang ◽

Zhixuan Han ◽

Xueqiu Wang ◽

Hanliang Liu ◽

Hui Wu ◽

...

Keyword(s):

Gold Deposit ◽

Metallic Nanoparticles ◽

Fine Fraction ◽

Geochemical Exploration ◽

Near Surface ◽

Theoretical Support ◽

Ore Bodies ◽

Micro Flow ◽

Fault Gouges ◽

Transitional Phase

Mineral deposits concealed by thick cover sequences present special problems for geochemical exploration. A variety of penetrating geochemical methods have been developed in the last few decades to explore for buried deposits. The theoretical basis of the mechanism by which metals migrate upward from buried deposits through the cover to the surface is still not fully understood. One hypothesis is that metal particles or metal elements could be carried onto bubbles or micro-flow of geogas and migrate upward to the surface. After years of study, nano-scale metal-bearing particles have been widely observed in geogas samples from different kinds of concealed deposits. However, the occurrence of these metal-bearing particles carried by geogases in near-surface media, such as soil, has not been studied in detail. In this study, metal-bearing nanoparticles were observed in samples from soils and fault gouges over the Shenjiayao gold deposit. The results indicate that (1) the ore-forming elements in soils can only come from deep-seated ore bodies and they occur in nanoparticles in the study area; (2) there is an obvious relationship between metal nanoparticles in fault gouges and soils; (3) the metallic nanoparticles in fault gouges represent a transitional phase along the whole vertical migration process. In addition, the observation results show that the metal-bearing nanoparticles tend to be adsorbed on the surface of clay minerals, which provide theoretical support for using fine fraction soils as sampling media to carry out geochemical exploration in sediment-covered terrains. Based on the results and discussion, a simple migration model was built in this paper.

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