The Betam gold deposit, located in the southern Eastern Desert of Egypt, is related to a series of milky quartz veins along a NNW-trending shear zone, cutting through pelitic metasedimentary rocks and small masses of pink granite. This shear zone, along with a system of discrete shear and fault zones, was developed late in the deformation …

osmium geochronology of ore-associated arsenopyrite and pyrrhotite was performed in an effort to delineate the timing of gold mineralization in relation to known tectonothermal events in the northern Black Hills. Arsenopyrite yields a rhenium–osmium (Re–Os) age of 1,736±8 Ma (mean squared weighted deviation=1.6), consistent with existing ...

Alteration assemblages at Chirano contrast with the graphite-carbonate-pyrite-arsenopyrite-pyrrhotite assemblages that dominate the lode gold deposits in southwest Ghana, which are hosted by graphitic shear zones and Birimian sedimentary rocks. ... Gold mineralization in the Ashanti Belt of Ghana; genetic constraints of the …

Abstract. A major gold province of the world exists in the Proterozoic Birimian and Tarkwaian supracrustal rocks of West Africa. The bulk of the gold comes from the primary lode occurrences of the Birimian rocks of Ghana (formerly The Gold Coast). Birimian lithofacies is characterised by subaqueous fine-grained sediments with bimodal …

The traditional concept of the Early Proterozoic gold deposits in Ghana — i.e. gold-bearing shear zones overlain by Tarkwaian paleoplacers containing reworked gold derived from the shear-zones — needs to be reconsidered in the light of recent research in Ghana, the Ivory Coast and French Guiana. This research has revealed a consistent pattern of …

Gold bonding in arsenopyrite, examined by transmission electron microscopy, is shown to be dispersed within the FeAsS crystal structure. ... Ashley, P.M., Creagh, C.J. and Ryan, C.G. (2000) Invisible gold in ore and mineral concentrates from the Hillgrove gold-antimony deposits, NSW, Australia. Mineralium Deposita, 35, 285–301.

Gold mineralization at Namdini is contained within sheared and highly altered rocks containing sulfides, mainly pyrite with minor arsenopyrite. Reserves. The Namdini project is estimated to contain 129.6 million tonnes (Mt) of probable ore reserves grading 1.14 g/t Au, while Contained gold is estimated to be 4.76Moz. Mining at …

The mineralization at Malati Pump is essentially Au-rich with only minor Sb. Gold (up to 3 g/t) is found in quartz–tourmaline–pyrite veins near the apex of the granodiorite pluton and is related to fine disseminated pyrite in the wall rock and as visible and microscopic inclusions in the pyrite (Kedda 1992).The exposed intrusion is a cupola …

Central Ashanti gold mine is located approximately 57km south-west of Obuasi and 195km north-west of Ghana's capital Accra. Formerly known as the Ayanfuri gold project, the mine produced in excess of 300,000oz of gold between 1994 and 2001. It is owned by Central Ashanti Gold Limited, a wholly owned subsidiary of Perseus, …

America, they propose that gold mineralization began with the precipitation of "invisible" gold in pyrrhotite and its subsequent dissolution and fixation in the matrix of later pyrite, arsenopyrite and quartz. This paper documents gold mineralization in the large Bogosu-Prestea mesothermal lode gold system of the

DISCUSSION A. Schmidt Mumm Æ T. Oberthu¨r Æ U. Vetter T. G. Blenkinsop High CO2 content of fluid inclusions in gold mineralisations in the Ashanti Belt, Ghana: a new category of ore forming ...

Most of the gold 27 mineralisation at West Branch is hosted by quartz-carbonate veins within the sheared and 28 hydrothermally altered meta-diorites that constitute the Greenschist Zone. At Tasiast, gold 29 mineralisation has been defined over a strike length >10 km and to vertical depths of 740 m.

Early workers on the Ashanti gold belt e.g. Cooper (1934) and Junner (1935) focused mainly on the visible minerals within the mineralised zones and considered gold to be younger because it is frequently included in pyrite and arsenopyrite. Leube et al. (1990) grouped gold mineralisation on the Ashanti belt into two types; Quartz Vein Type

The Sanshandao gold deposit is located in the western part of the Jiaodong gold province, about 30 km north of Laizhou City (Fig. 1).The gold mineralization is confined to a major fault zone (Sanshandao fault) that cuts the Sanshandao granodiorite (Fig. 2), a body of the Guojialing granodiorite suite.The deposit is a typical Jiaojia-type …

In the Obuasi deposit, two distinct styles of gold mineralisation occur; (1) goldbearing sul- phides, dominantly arsenopyrite, disseminated in metasedimentary rocks and (2) native gold hosted in quartz veins up to25 m wide. Both mineralisation styles are contained in high grade ore shoots classified in three groups on the

The gold mineralization of Ghana is either primary along the shear-zones in the Birimian of the Gold Coast Range (Ashanti-type or Bl-hosted deposits) where production over the past century has exceeded 1000 t (Kesse 1985), or secondary in quartz-conglomerates (Tarkwa-type or Tarkwaian-hosted deposits) of the Tarkwaian Banket Formation (Fig.

In the Siguiri basin, most gold deposits are found within sedimentary formations as e.g. Siguiri and Lefa gold mines (Anon., 2009). Gold mineralisation found in the Birimian units of the Siguiri basin is related to late tectonic plutonism and hydrothermal events that have remobilised gold along fractures and fault zones (Anon., 2009).

This review compares genetic parameters of 12 orogenic gold deposits. The set of examples is considered to represent largely the variability of orogenic gold deposit (OGD) characteristics. The data are presented in tables and include following definitive parameters: regional geologic settings, nature of hosts rocks and mineralization, ore …

The mineralization occurred in three paragenetic stages from at least a two-phase hydrothermal fluid, with stage II forming a prolonged and main stage of the ore and gold mineralization. Redox changes in ore fluid which were triggered by episodic pressure releases during fissuring and fracturing caused fluctuation of the activity of the As/Ni ...

The bulk of the granitoid-hosted gold mineralization at Edikan is associated with two principal sets of gold-bearing quartz veins, including low-angle fault-fill veins controlled by thrusts and ...

Ghana is the largest producer of gold in West Africa, a region with over 2,500 years of history with regards to gold production and trade. Modern exploration for and mining of gold in Ghana dates ...

Arsenopyrite is formed in hydrothermal deposits, especially those formed at medium to high temperatures. It is often associated with other sulfides such as pyrite and chalcopyrite. CLARK COUNTY: Reported from an unspecified locality in the county as particles in a quartz veins that also yielded some silver and gold values when assayed (Irving, 1882). …

The Au mineralization in the Kubi Gold Mining Area in the Birimian of Ghana is associated with garnet (about 85 vol.%), magnetite, pyrrhotite, arsenopyrite, and sulfide minerals, as well as quartz with gold and calcite. These minerals and the included elements can act as indicator minerals or pathfinder elements. For the present work, we …

However, cratonization in Africa, in a broad sense, was diachronous, ranging from ca. 3.0 Ga in the Barberton greenstone belt, through ca. 2.6-2.5 Ga in the Zimbabwe and Tanzanian cratons, to the ca. 2.0 Ga Eburnean event of West Africa, the latter contributing to the important gold mineralization of southwest Ghana.

The Ashanti belt of Ghana is the key district of gold mineralization in the Paleoproterozoic terrane of West Africa. The area considered in southwest Ghana is covered by lithologies of the volcanic-sedimentary Birimian Supergroup and the overlying clastic sedimentary Tarkwaian Group which were jointly folded and metamorphosed …

In Ghana the Birimian granite-greenstone terrane consists of five, evenly spaced, NE–SW-trending volcanic belts and intervening sedimentary basins (Fig. 2). ... The predominant sulfide mineral is pyrite, whereas arsenopyrite±gold inclusions are subordinate. In the vicinity of sulfide-bearing quartz veins arsenopyrite replaces pyrite …

Other gold deposits developed inside intrusions include the Ahafo South Camp in Ghana, where most of the Au-bearing shear zones are located in mafic chonolith (Masurel et al., 2021), the Nogbele ...

Gold mineralisation at Damang in the southwestern part of Ghana occurs in two types of geological settings: (1) as paleoplacer in the Banket Series conglomerates of the Tarkwaian system and (2) in ...

The Ashanti belt of Ghana is the key district of gold mineralization in the Paleoproterozoic terrane of West Africa. The area considered in southwest Ghana is covered by lithologies of the … Expand

Here Au mineralization is developed as free gold in the matrix of the conglomerates. This style of mineralization is interpreted by Sestini, 1973, Hirdes and Nunoo, 1994 and this paper to be paleoplacer in origin and makes up approximately 20% of the total resource at Damang. The other style of Au mineralization is found in close …