Shale | Properties, Composition, Formation, Uses » Geology …
Black shale result presenced of greater than one percent carbonaceous material and indicates a reducing environment.Red, brown and green colors are indicative of ferric oxide ... Black carbonaceous shale which owes its color to organic matter (>5%). It is rich in sulfide minerals and contains elevated concentrations of several metals (V, U, …
The characteristics and formation of black shale-hosted …
Black shale-type gold deposits are hosted in a wide range of carbonaceous sediments from the Proterozoic to the Mesozoic-Cenozoic. Asia alone contains more than 15 giant and large gold deposits of this type, containing a total resource of more than 12, 000 t of Au.
Geology, Geochemistry and Mineralogy of Hyper-Enriched Black Shale …
Hyper-enriched black shale (HEBS) deposits are a globally important resource for base-, strategicand precious-metals. In northern Yukon, thin (3 to 40 cm-thick) HEBS deposits occur sporadically over 1000s of km at the Road River Group-Canol Formation contact. The deposits in each location share lithological and geochemical characteristics (particularly …
The origin of Cretaceous black shales: a change in the …
It is obvious that the oceanic setting at the time of black shale formation was anoxic; hence the expression "Oceanic Anoxic Event" was introduced to denote the events in the mid-1970s. 9) Sedimentologically, the presence of fine laminae in black shale is a smoking gun of bottom-water anoxia (Fig. (Fig.1 1). 50) Fine laminae in black shale ...
Multi-stage metal enrichment and formation of gold
Black shales may serve as an important source of metals such as Co, Ni, or As, largely due to anoxic to euxinic conditions in association with high concentrations of sulfur leading to efficient scavenging and transport of metals from seawater into the seafloor sediment. We report on an unusual type of Au mineralization newly discovered in …
Gold mineralization in Proterozoic black shales: …
The Proterozoic black shales rich in gold, sulfur, and organic matter, which were deposited in the Proterozoic continental margin rifts, comprised the source bed for …
The characteristics and formation of black shale …
Auriferous deposits located in black shale are among the most attractive long-term targets for gold exploration. Black shale-type gold deposits are hosted in a wide range of …
(PDF) Gold-tourmaline mineralization in carbonaceous shales …
These processes produce regionally extensive black shale and turbidite sequences enriched in syngenetic gold and arsenic, commonly from 5 to 100 ppb Au and 10 to 200 ppm As. Rare organic- and ...
Cu isotopes and concentrations during weathering of black shale …
To understand black shale weathering, a geochemical survey was initiated for soils developed on shales of the Marcellus Formation at a zero-order catchment at a satellite site of the Susquehanna/Shale Hills Critical Zone Observatory located in Jackson Corner, Pennsylvania. ... This formation is an organic- and metal-rich, carbonaceous shale ...
black carbonaceous shale and gold mining
black carbonaceous shale and gold mining. Unconventional Resources - Petroleum Agency SA. The Frontier Geology Department is aptly named as its focus is the evaluation and promotion of South Africa's unconventional …
Кey issues for improving of carbonaceous ore beneficiation …
According to the ore composition and structural features of black-shale blocks, the studied subjects are associated with big large-volume gold deposits belonging to black-shale formation: 1) dispersed, finely disseminated condition of noble metal mineralization; 2) presence of carbonaceous matter in ore-bearing rocks; 3) presence of …
Black Horse Group Mine – Western Mining History
black horse tungsten vein was mined for scheelite to a depth of 100 ft, and explored to a depth of 200 ft. comment (geology): ore in two quartz-calcite veins along bedding faults ore in two quartz-calcite veins along bedding faults. limestone, shale, carbonaceous shale and carbonaceous limestone; striking e, dip n.
A black shale protolith for gold-tellurium mineralisation in …
This study reinforces previous evidence that microbial sulphate reduction is the starting point that leads ultimately to Au-Te ore formation in black shale sequences (Chang et al. 2008; Tomkins 2013), and supports a more general model of Au concentration in pyritic, carbonaceous sediments (Pitcairn 2011; Gaboury 2013; Tomkins 2010, 2013). …
Critical Metals in Black Shales | U.S. Geological …
Black shales have been of increasing interest in recent years due to their oil and gas potential, but also because many are enriched in nonfuel "unconventional" …
Кey issues for improving of carbonaceous ore …
According to the ore composition and structural features of black-shale blocks, the studied subjects are associated with big large-volume gold deposits …
Multi-stage metal enrichment and formation of gold …
Black shales, marine siliciclastic rocks with > 1 wt% of total organic carbon (TOC) content, may serve as an important source of metal accumulations, notably redox …
A black shale protolith for gold-tellurium …
The host succession includes carbonaceous, pyritic shales (pelites) which were a source of trace elements, including gold and tellurium. LA-ICP-MS mapping of pyrite crystals shows that late stages …
(PDF) Spontaneous combustion of carbonaceous shale at an …
Abstract and Figures. Spontaneous combustion during coal mining operations is a major problem that affects the health and safety of workers and causes environmental problems. The phenomenon is ...
(PDF) Gold-tourmaline mineralization in …
Black shale deposits are carbonaceous type and belong to terrigenous-carbonaceous and silicon-carbonaceous formations. Among the main minerals in shales are noted: quartz, sericite,...
black carbonaceous shale and gold mining
According to the ore composition and structural features of black-shale blocks, the studied subjects are associated with big large-volume gold deposits belonging to black-shale formation: 1) dispersed, finely disseminated condition of noble metal mineralization; 2) presence of carbonaceous matter in ore-bearing rocks; 3) presence of native ...
Spontaneous combustion of carbonaceous shale at an iron …
In 2020, a premature detonation incident occurred at an iron ore mine where the waste material contains black carbonaceous shale units known to be associated with pyrite. The spontaneous combustion propensity and properties of samples of the black carbonaceous shales from the mine were examined and compared with samples from the Witbank …
The origin and hydrothermal mobilization of carbonaceous matter
Carbonaceous metasediment or black shale-hosted gold deposits have attracted much attention in recent years for their high tonnage and suitability for open-pit mining (Bierlein et al., 2001;Henne ...
Mobility and environmental impact of cadmium (Cd
The western Hunan province is located in the middle of the so-called South-China black shale horizon (SBH) [51], of which black shales of the Lower-Cambrian represent one of the major components of the SBH (Fig. 1 a). Black shales in this area consist mainly of carbonaceous, phosphorite-bearing, stone-coal, silty, and siliceous …
Organic carbon cycling and black shale deposition: an Earth …
INTRODUCTION. Earth's surface can be divided into four 'spheres': the lithosphere, biosphere, atmosphere and hydrosphere. The cycling of organic carbon produced by organisms in the atmosphere, oceans, land and mantle reservoirs is a particular characteristic of Earth [1, 2] (Fig. 1).The 'Gaia hypothesis' proposed by …
black carbonaceous shale and gold mining
Below the jasperoid breccia are thin contorted beds of black carbonaceous shales. In one area the southeast dipping shales are cut by an altered igneous dike mostly altered to clays. The Horse Canyon deposit was discovered about 1982 and open pit gold mining commenced in 1983 employing 106 workers. Finegrained gold is disseminated
RARE-EARTH MINERALS IN CARBONACEOUS SHALE OF …
gold mineralization patterns and material constitution [11–14]. The geomechanical peculiarities of the ore-hosting black shale, carbon matter and rare-earth min-eralization were neglected. Research methods The geochemistry of carbonaceous shales was stud-ied using the microanalysis by ICP-MS spectrometry on
A black shale protolith for gold-tellurium …
Abstract. The Dalradian Supergroup of Britain and Ireland is mineralised by gold-tellurium vein deposits. The host succession includes carbonaceous, pyritic …
Gold mineralization in Proterozoic black shales: Example …
The Haoyaoerhudong gold deposit in the northern margin of the North China Craton (NCC) is a large tonnage lower-grade deposit with a reserve of about 148 tons of gold. Gold mineralization is characterized by pyrite and pyrrhotite films and thin veins on the schistosity plane of the Proterozoic black shales.The orebodies, strictly controlled by …
Reducing preg-robbing in carbonaceous gold ores using passivative …
1. Introduction. Carbonaceous gold ores are considered problematic as the native carbonaceous matter within the ore acts as a sink for the gold cyanide complex, competing with the added activated carbon during leach and recovery operations (Pourdasht, 2018).These ores are commonly called preg-robbing as the Au cyanide …
black carbonaceous shale and gold mining
black carbonaceous shale and gold mining. Shale - Wikipedia. Shale is a fine-grained, clastic sedimentary rock, formed from mud that is a mix of flakes of clay minerals and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. Shale is characterized by its tendency to split into thin layers less than one ...
