(PDF) Metavolcanic host rocks, mineralization, and gossans …
The gossans are interpreted to represent relict massive sulphides that have undergone supergene weathering; 'chert' beds within these massive sulphide deposits may be leached wall-rock gossans ...
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Gossan | Oxide Minerals, Iron Ore & Sulfide Minerals
Gossan, rust-coloured oxide and hydroxide minerals of iron and manganese that cap an ore deposit. Gossans form by the oxidation of the sulfide minerals in an ore deposit and they thus may be used as clues to the existence of subsurface ore deposits, especially if distinctive boxworks are present.
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Gold, wolframite, tourmaline-bearing lateritized gossans in …
Gossans The gossans are represented by several outcrop- ping tabular ferruginous bodies ranging from 1 to 3 m wide, associated or intercalated with brittle quartz veins and kaolinitic zones. One of the best exposures of gossans from this area was obtained in trench 35 (Fig. 3), where wolframite agregates were first de- scribed by the …
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Important of Gossans in Mineral Exploration: A Case Study …
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein. In the 19 th and 20 th centuries gossans were important guides to buried ore deposits used by prospectors in their quest for metal ores. An experienced prospector could read the clues in the structure of the …
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Topical study of lead-zinc gossans
Even in cases of "ideal gossans" in which there appears to be excel-lent cavity reproduction of former sulfides, gossan porosity determina-tions made by standard weighing …
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The geochemistry of selected base-metal gossans, southern Africa
Geochem. Explor., 22: 161--192. A comparative study of the gossans from ten base-metal deposits in southern Africa included the establishment of geochemical criteria for regional evaluation of gossans and ironstones. Factors such as ore composition, nature of gangue, element mobility, depth of weathering, degree of erosion and …
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The geochemical association Au–As–B–(Cu)–Sn–W
The gossans show the highest average contents for the majority of the determined elements (Au, As, B, Cu, Mn, Mo, Ni, Pb, Sn, W, Y and Zn), followed by the laterites (Ga, Hg, Sc, Sn and V). Only Zr is more concentrated in the latosols. The abundances for many of the gossan elements vary widely; exceptions are Mo, Ni, Zn, Ga …
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Detecting and mapping gossans using remotely-sensed …
High Lake Gossan appears orange-yellow in colour. +3. (A) Red/Blue (LANDSAT-7 bands 3/1) ratio highlights the High Lake Gossan. This ratio leverages high reflection of red energy-the reason why ...
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Gossan
The other varieties of gossan contain quartz and iron oxides, goethite, limonite, and jarosite, which form as pseudomorphs. Although mostly red in color, gossans also appear …
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Mineragraphy | SpringerLink
The term gossan is applied to oxidized, leached, and commonly cellular exposures of sulfides either at the surface or beneath superficial cover, but within a zone of oxidation.Cap rock, although an alternate term, usually refers to outcrop expressions of sulfide ore bodies.. An appreciation of the significance of gossans in particular, and of leached rock …
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The geochemistry of gossans associated with Sarcheshmeh …
The mature gossans overlying the Sarcheshmeh porphyry copper ores contain abundant hematite with variable amounts of goethite and jarosite, whereas immature gossans consist of iron-oxides, malachite, azurite and chrysocolla. In mature gossans, Au, Mo and Ag give significant anomalies much higher than the background concentrations.
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Yilgarn Nickel Gossan Geochemistry – a Review, with New …
Moeskops, P.G., 1977. Yilgarn nickel gossan geochemistry – a review, with new data. J. Geochem. Explor., 8: 247–258. Recent chemical investigations by the author on 40 Ni ores, 103 true gossans and 69 false gossans (collected from 32 localities, including most producing nickel mines) have largely supported the findings of previous …
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Gossan and Ironstone Surveys
The gossans consist of goethite, hematite and resistate minerals, particularly barite, together with minor malachite, chrysocolla and alunite-jarosite minerals. The …
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Simplified illustration showing the enrichment of primary …
The presence of two gossans in Area 4 provided the first opportunity to investigate the potential effects of the deposits on stream water and sediment geochemistry in this region ( Williamson et ...
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An isotopic and trace element investigation of gossans from Troodos
The Troodos ophiolite is widely accepted to be a fragment of Mesozoic oceanic crust, which uplifted during Alpine orogeny, due to the collision of Eurasia and Africa (Gass and Masson-Smith, 1963; Vibetti, 1993; Adamides, 2011; Antivachis, 2015). It belongs to supra-subduction ophiolites, which probably set up during subduction initiation associated with …
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Gold remobilization in gossans of the Amani area
Gold remobilization in gossans of the Amani area, southwestern Tanzania. Gossan caps contain supergene gold hosted in iron oxyhydroxides. Supergene gold has …
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Important of Gossans in Mineral Exploration: A Case Study in …
Although most gossans are red, orange, or yellow, black gossans from manganese oxides such as pyrolusite, manganite, and especially psilomelane form at …
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Mineragraphy | SpringerLink
The presence of concealed gossans is usually noted from subsurface geochemical and geophysical anomalies and from samples obtained from percussion drilling, …
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Metavolcanic host rocks, mineralization, and gossans of …
alteration. The gossans are interpreted to represent relict massive sulphides that have undergone supergene weathering; 'chert' beds within these massive sulphide deposits may be leached wall-rock gossans that experienced silicification and Pb–Ba–Fe enrichment from acidic groundwaters generated during gossan formation. ARTICLE HISTORY
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REMOTE SENSING AND COMPOSITIONAL ANALYSIS OF …
gossans. Spectral and compositional data acquired in the laboratory will be used to create a spectral library of Martian analogue gossans. It will be used in spectral unmixing algorithms to locate gossans on a WorldView-2 multispectral image (2 m/pixel) and a PRISMA hyperspectral image (30 m/pixel). Linear and
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Gossan | SpringerLink
The Cornish term gossan is applied to chemically weathered, iron-stained outcrops of sulfide mineral deposits. Synonyms include the French chapeau de fer, the German eiserner Hut, and the Spanish colorados. The term pacos ore is used in Bolivia for gossans over tin veins that are residually enriched in cassiterite.Most workers reserve the term "capping" for …
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Gossan
Gossan refers to the rust-colored capping or staining of a mineral deposit, which is mostly formed due to the oxidation or alteration of iron sulfides. Gossan generally appears as a red stain against the background rock and soil, due to the presence of a large quantity of oxidized iron. It gets its name from a Cornish miner's slang "gōs ...
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CÔNG TY TNHH SẢN XUẤT GẠCH BLOCK HỮU THẮNG. Điện thoại : 0962 33 74 79 - 0347 36 16 17. Email : [email protected] Website ...
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(PDF) Detection of Gossan Zones in Arid Regions Using
The Khunayqiyah gossans, Eastern Arabian Shield, Saudi Arabia, have been used to demonstrate the effectiveness of using the Landsat 8 OLI imagery for detecting and delineating of gossan zones in ...
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Landsat 8 OLI Data
Mineralogically, massive gossans consist mainly of limonite, goethite, hematite, malachite, and azurite (Fig. 4f). In addition to the four known ore bodies or …
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Gossan | Oxide Minerals, Iron Ore & Sulfide Minerals
Gossan, rust-coloured oxide and hydroxide minerals of iron and manganese that cap an ore deposit. Gossans form by the oxidation of the sulfide minerals in an ore deposit and they …
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A method of distinguishing nickel gossans from other …
These samples have been positively identified as true gossans or ironstones derived from other parent rock types described herein by examination in polished and/or thin section and by correlating the weathered outcrop samples with known ore or rock equivalents at depth in mine workings or drill core. Of the 430 samples, 250 are from 22 …
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43rd Lunar and Planetary Science Conference (2012) …
of gossans have identified both chemolithotrophs [8, 9] and microbial fossils, preserved as hydrous ferric oxide (HFO) coated filaments [10, 11]. The purpose of this study is to investigate the formation of mineralogic biosignatures in gossans related to HFO precipitation in association with microbial communities.
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A Deep Learning Approach to the Detection of Gossans in …
Gossans are surficial deposits that form in host bedrock by the alteration of sulphides by acidic and oxidizing fluids. These deposits are typically a few meters to kilometers in size and they constitute important vectors to buried ore deposits. Hundreds of gossans have been mapped by field geologists in sparsely vegetated areas of the Canadian Arctic. …
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An isotopic and trace element investigation of gossans from …
The Troodos ophiolite is widely accepted to be a fragment of Mesozoic oceanic crust, which uplifted during Alpine orogeny, due to the collision of Eurasia and Africa (Gass and …
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Gossan-7 formed close to the contact of metamorphics of
Gossans are important guides to buried metallic ore deposits and are usually found in the upper and exposed part of an ore deposit or mineral vein, which involves intensely …
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Gossan
Although most gossans are red, orange, or yellow, black gossans from manganese oxides such as pyrolusite, manganite, and especially psilomelane form at the oxidized portion of Manganese-rich mineral deposits. In the 19th and 20th centuries, gossans were important guides to buried ore deposits used by prospectors in their quest for metal ores.
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Gossan Definition & Meaning | YourDictionary
Gossan definition: An exposed, oxidized portion of a mineral vein, especially a rust-colored outcrop of iron ore.
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Supergene features and evolution of gossans capping
Twelve massive sulphide deposits from the Iberian Pyrite Belt (IPB) show well-preserved iron caps, some of which were mined during the last century to recover precious metals (e.g., Tharsis, Rio Tinto, San Miguel). Field observations and correlation assays between the distinct mineral sequences at different deposits suggest that all the …
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Microtextural evaluation of nickel sulphide gossans in …
The use of reflected light microscopy to examine microtextures preserved in the surface gossans from a supergene pyrite-violarite-marcasite sulphide assemblage has allowed the refinement of geochemical classification schemes. The preservation of supergene zone textures by pseudomorphous Si–Fe replacement often permits the …
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Gossan-7 formed close to the contact of …
Gossans are important guides to buried metallic ore deposits and are usually found in the upper and exposed part of an ore deposit or mineral vein, which involves intensely oxidized and weathered ...
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(PDF) Important of Gossans in Mineral …
There are 8 gossans outcrops in NE-SW orientation in the area of 1.6 km in length among units targeted for mineralization. The presence of these gossans indicates that there may be mineralization ...
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13. Weathering Processes
chemistry of seafloor gossans (Mills and others, 2001) has been interpreted in terms of precipitation from low-tempera-ture vent fluids and hydrogenous reactions involving ambient seawater. However, seafloor weathering of unstable sulfide minerals ultimately produces metal oxides and oxyhydroxides, so some gossans must be a product of halmyrolysis.
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Mineralogical and textural evolution of the Alvo 118
The Carajás Mineral Province is home to one of the most extensive copper-gold belts globally, where hypogene orebodies were partially transformed into gossans.The Carajás Mountains host mature gossan profiles modified by lateritization.Conversely, the surrounding denuded landscape holds deep immature gossans characterized by …
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