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

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 ...

Abstract. Black shales are sedimentary rocks containing >0.5% of organic carbon. They host polymetallic deposits which have been mined for Cu, Ni, Zn, Mn, P, …

A shale with at least 1% carbonaceous material indicating a reducing environment. A dark, thinly laminated carbonaceous shale, exceptionally rich in organic matter (5% or more carbon content) and sulfide (esp. iron sulfide, usually pyrite), and often containing unusual concentrations of certain trace elements (U, V, Cu, Ni).It is formed by partial anaerobic …

Shale is the most common sedimentary rock, accounting for about 70 percent of the rock in the Earth's crust. Shale is a fine-grained rock made from compacted mud and clay. The defining characteristic of shale is its ability to break into layers or fissility. Black and gray shale are common, but the rock can occur in any color.

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 …

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" …

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 …

Black-shale deposits of the Kumak ore field according to the parameter Na2O/K2O = 0.62 belong to the normal potassium formation type, which is typical for deposits with mainly gold-sulfide ...

Abstract. The Dalradian Supergroup of Britain and Ireland is mineralised by gold-tellurium vein deposits. The host succession includes carbonaceous, pyritic …

Highly metalliferous black shales (HMBS) are enriched in organic carbon and a suite of metals, including Ni, Se, Mo, Ag, Au, Zn, Cu, Pb, V, As, Sb, Se, P, Cr, and U ± PGE, compared to common black shales, and are distributed at particular times through Earth history. They constitute an important future source of metals. HMBS are relatively …

Minor precipitation also takes place, and all these fine sediments become a fine-grained sediment rock called shale. When deposition is under reducing conditions, carbonaceous or black shale formation takes place. In carbonaceous shales, the presence of heavy minerals like uranium, vanadium, and zinc has been observed.

Highlights. •. Extraction of key metals from black shales was reviewed. •. Black shales are often enriched in V-Mo-U-Ni-Zn. •. Sulfides, organometallic complexes …

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 …

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 ...

The Kopylovsky and Kavkaz gold deposits in the Artemovskiy ore cluster, Bodaybo district, hosted in terrigenous carbonaceous sequence of the Dogaldyn formation of the Upper Proterozoic Bodaybo group, are localized in cores of high-order anticlines. These deposits contain gold-sulfide and gold-sulfide-quartz ore types. Pyrite is the …

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 ...

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 …

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 …

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 ...

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 …

According to the ore composition and structural features of black-shale blocks, the studied subjects are associated with big large-volume gold deposits …

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 elevated attention in respect to mineral processing in the past couple of decades has principally been focused on four black shale deposits: (i) Kupferschiefer Cu-Ag ore (Poland and Germany) (Borg et al., 2012), (ii) Ni-Mo-PGE polymetallic ore in Guizhou province and its extension in other districts (China) (T. Han et al., 2014), and (iii) …

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, …

Carbonaceous materials in black-shale rock specimens from three gold-ore deposits located in Russia and Kazakhstan have been investigated by micro-Raman spectroscopy using near-ultraviolet, visible, and near-infrared wavelength excitation. Only the 325-nm (3.8 eV) wavelength laser line excitation yielded the Raman spectra for all …

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.

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,...

Because of the high organic carbon concentration in carbonaceous shale, a large proportion of carbonaceous shales are often misclassified into coals using visible and near-infrared (VIS-NIR) …

Carbonaceous Shale: High in organic carbon, often black or dark gray, indicating an anoxic depositional environment. Bituminous Shale: Contains significant amounts of bituminous material, making ...

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). …

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 ...

2.2 Analytical characterization 2.2.1 Sampling program. Using Standard method (ASTM 2010), coal samples were collected from one of the largest coal mines in the Makum coalfield.The rock types were mainly sandstone, shale, and carbonaceous clay. Several coal, MOB, and shale samples were gathered from three distinct sites (shown in …

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 …

Clay Lake Drill Core – Sandstone and Carbonaceous Shale Stockwork Zone. The Clay Lake gold target extends for 2 km by 1 km, (c.140 ha / 350 acres) and lies at the north-eastern end of the 40 mile gold trend which Conroy Gold has discovered. This target was named after the Clay Lake Nugget; a 30.05g nugget with a gold content of 28g.

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 ...

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 …

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.

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 …

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 …