Geochemistry of native gold from deposits of various types

Nikolaeva, L. A.; Nekrasova, A. N.; Milyaev, S. A.; Yablokova, S. V.; Gavrilov, A. M.

doi:10.1134/s1075701513030045

Cited by 19 publications

(25 citation statements)

References 4 publications

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“…In complex with another typomorphic features it becomes an additional criterion for primary source determination (Glushkova and Nikiforova, 2011;Nikolaeva et al, 2013). (analyst Galankina O.)…”

Section: Gold Particles Researchmentioning

confidence: 99%

Primary Au prospecting results in the Logrosán area (Central Iberian Zone, Spain).

Cheremazova¹,

Скублов²,

Новоселов³

et al. 2015

Journal of Iberian Geology

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The Central Iberian Zone presents an exceptional geological interest for its great exploration potential for a number of elements including gold. Metallogeny within the area is mainly related to regional metamorphism and late magmatic activity during the Variscan orogeny. In 2013-2014 junior company Mineral Exploration Network Ltd. has carried out an extensive prospecting field work with a primarily view to discover Au within the area around Logrosan granitic pluton (Cáceres, Spain). The main output of the survey was a localization and presorting of potentially mineralized territory unites at the extensive spatial scale (more than 240 sq. km). The known gold showings in the Central Iberian zone are considered to be synorogenic with a mainly metamorphic fluid source. As arsenic commonly forms widespread geochemical haloes near practically all orogenic gold deposits and appears to be easily and credibly measured by express analytical methods (XRF), it was selected as one of the major pathfinder elements for the initial prospecting. Designed geochemical survey allowed delineating potential target area with contrastive complex As-W-Zn-Pb anomaly in soil sediments and significant quantities of gold particles in heavy mineral concentrates. Placer gold particles analyses and their typomorphic features confirmed nearby primary gold source existence. The suggested scope of work proved to be efficient for assessing mineralization potential and selecting perspective target areas for a detailed drilling.Keywords: gold exploration, Central Iberian Zone, pan concentrate, geochemical soil sampling, Iberian Variscan Belt Resumen La Zona Centro Ibérica muestra un interés geológico excepcional debido a su gran potencial de exploración de gran número de elementos, incluido el oro. La metalogenia en esta área está relacionada con un metamorfismo regional y posterior actividad magmática durante la orogenia Varisca. Durante el periodo 2013-2014, la compañía Mineral Exploration Network Ltd llevó a cabo una prospección importante en el campo con una primera observación de Au dentro del área del plutón granítico de Logrosan (Cáceres, España). El primer objetivo de la campaña fue la localización y acotamiento de la zona potencialmente mineralizada a gran escala (más de 20 Km2). El oro descrito es considerado sinorogénico con una fuente principal relacionada con fluidos metamórficos. Como el arsénico aparece frecuentemente constituyendo geoquímicos halos cerca de la mayoría de los depósitos orogénicos de oro y parecen ser medidos fácilmente mediante métodos analíticos (XRF), fue seleccionado como uno de los principales elementos marcadores para realizar la prospección inicial. Los análisis geoquímicos seleccionados permitieron delimitar la zona de interés mediante el contraste del complejo anómalo As-W-Zn-Pb en los sedimentos del suelo y cantidades significativas de partículas de oro en concentraciones de minerales pesados. Los análisis de las partículas de los placeres de oro y sus características tipomórficas confirmaron inicial...

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Section: Gold Particles Researchmentioning

confidence: 99%

Primary Au prospecting results in the Logrosán area (Central Iberian Zone, Spain).

Cheremazova¹,

Скублов²,

Новоселов³

et al. 2015

Journal of Iberian Geology

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“…The indicators of placer gold (morphology, impurity elements, microinclusions, internal structures, etc.) carry extensive information about the nature of native gold, both in endogenous and exogenous conditions [1][2][3][4][5][6][7][8][9][10][11]. In exogenous conditions, the evolution of placer gold occurs, but it retains the "memory" of its primary sources.…”

Section: Introductionmentioning

confidence: 99%

“…The internal structures of placer gold were first studied by Petrovskaya and Fastalovich [12]. Then, Nikolaeva [2], Popenko [3], Savva and Preis [4], Nikolaeva et al [8] and Savva et al [5,13] studied the internal structures of placer gold. They studied the internal structures of native gold from endogenous sources, as well as zones of hypergenesis and alluvial placers.…”

Section: Introductionmentioning

confidence: 99%

“…In the oxidation zone, they identified the formation of a high-grade shell on low-grade gold, as well as the presence of high-grade veinlets. According to L.A. Nikolaeva et al [8], the structures of primary crystallization and structures caused by intra-and post-ore transformations are recognized in ore gold. The authors revealed that the gold of shallow-depth deposits is characterized by zonal structures, with a gold fineness of less than 800‰, and the gold of medium-depth deposits with a fineness of more than 800‰ is characterized by unclear zonal structures.…”

Section: Introductionmentioning

confidence: 99%

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Internal Structures of Placer Gold as an Indicator of Endogenous and Exogenous Processes

Nikiforova

2022

Minerals

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The study of the internal structures of placer gold on the territory of the east of the Siberian platform, overlain by a thick cover of Mz-Kz deposits, where traditional methods of searching for gold deposits are not effective, allowed us to determine, for the first time, the stages of ore formation and conditions of its occurrence. The identified indicators of the internal structures of placer gold (structures of primary recrystallization, secondary recrystallization, thick high-grade shells) indicate that placer gold content is formed mainly due to the supply and repeated redeposition of native gold from ancient gold-bearing deposits of the Precambrian stage of ore formation to younger ones. The discovered coarse-, medium-grained, mono-grained, unclear-zonal, granulation and disintegration structures suggest a supply of gold from nearby ore sources of the Mesozoic stage of ore formation. In the weathering crust, a high-grade shell is formed. In the hydrodynamic environment, the internal structures of gold practically do not change and fully correspond to the internal structures of endogenous gold. In aeolian conditions, the internal structures are transformed. In ancient gold-bearing conglomerates, under the impact of lithostatic pressure, as well as in metamorphogenic conditions, when the PT conditions change, the internal structure changes. Thus, for the first time, on a huge factual material, it is proved that the internal structures contain extensive information both about the endogenous origin of gold (the stages of ore formation—Precambrian and Mesozoic) and about its transformation in various exogenous conditions. The identified indicator of the internal structures of placer gold for certain types of sources contribute to a more correct selection of methods for searching for ore and placer gold deposits in closed territories and assessing their prospects. The use of this method makes it possible to develop criteria for forecasting different sources and types of gold deposits based on internal structures.

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“…For example, sedimentary pyrite generally has Co/Ni ratios of <1 (Bajwah et al ., 1987), while hydrothermal pyrite generally has Co/Ni ratios of >1 (Bralia et al ., 1979). In addition, the occurrence and chemical composition of gold grains can offer information of the source of metals (Nikolaeva et al ., 2013; Altigani et al ., 2016).…”

Section: Introductionmentioning

confidence: 99%

Metal source of gold deposits in the Jiaoxibei area, Eastern China: Insights from trace element analysis of gold and pyrite

Fan

Yin

et al. 2021

Resource Geology

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The metal source of gold deposits in the Jiaoxibei area, eastern China, has been investigated by many researchers, but no consensus has been reached so far. In this study, three typical gold deposits, the Xinli, Jiaojia, and Dayingezhuang deposits, were selected for trace element analysis of gold and pyrite to constrain the metal source. Pyrite from these three deposits has similar morphological and compositional characteristics, and can be divided into three types: Py1 with euhedral to subhedral textures, Py2 with subhedral to anhedral textures with micro‐fractures, and Py3 with subhedral to anhedral textures and intergrowing polymetallic sulfides. Among them, Py2 and Py3 were formed in the main ore‐forming stage and they are the dominant host minerals of visible gold. In these deposits, visible gold occurs mainly in micro‐fractures or as inclusions in Py2 and Py3. Most of the pyrite has extremely low concentration of invisible gold, indicating that visible gold in the Jiaoxibei district is not a product of the remobilization of invisible gold from earlier pyrite. Both Py2 and Py3 are characterized by low Co concentration of <100 ppm and Co/Ni ratio of <1, which are similar to those of pyrite in sedimentary rocks. Therefore, ore‐forming metals of these gold deposits in the Jiaoxibei district may originate mainly from a sediment‐related metal source.

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Geochemistry of native gold from deposits of various types

Cited by 19 publications

References 4 publications

Primary Au prospecting results in the Logrosán area (Central Iberian Zone, Spain).

Primary Au prospecting results in the Logrosán area (Central Iberian Zone, Spain).

Internal Structures of Placer Gold as an Indicator of Endogenous and Exogenous Processes

Metal source of gold deposits in the Jiaoxibei area, Eastern China: Insights from trace element analysis of gold and pyrite

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