This document provides information on prospecting for gold along river banks. It discusses various types of secondary gold deposits that can form in fluvial environments, including imbrications, superficial enrichment near the surface, influences of bedrock, and fluvial traps behind boulders. It also describes how to identify pay streaks, which are enriched areas within rivers that may contain higher quantities of gold. Pay streaks can be simple, formed by one large flood, or complex with multiple cores deposited over time. The document contains diagrams and photographs to illustrate fluvial geological concepts and real examples of features that may indicate gold deposits.
The document discusses mine waste issues at the Sukari Gold Mine in the Eastern Desert of Egypt. It notes that mine wastes from gold mining and processing contain hazardous substances like heavy metals, acids, and chemicals that can pollute the surrounding environment if not properly disposed of and monitored. The wastes are produced from mining activities, mineral processing plants, and smelting and are in the forms of solids, liquids, and gases. At Sukari, waste rock is disposed of in rock dumps, but these are not sealed and allow contaminated water to seep into surface water and groundwater, causing acid mine drainage issues. Waste water from processing contains reagents, solvents, acids, and contaminated groundwater and needs treatment
Rivers erode, transport, and deposit material as they flow across the landscape. There are four main types of erosion by rivers: abrasion, attrition, hydraulic action, and solution. Transportation occurs through traction, saltation, suspension, and solution. Deposition takes place when the river's speed or volume decreases, such as when entering a lake or plain. A river's work depends on its energy, which is determined by the volume of water and flow speed according to the gradient.
Aggregate Used in Concrete & Building Purposes; صخورالصوان (Chert)
درنات او عقيدات الشيرت(Nodular or Concretion Cherts)
زلط الطواحين (Mill chert)
الشيرت الطبقى (Bedded Cherts )
رواسب الكالسيوم الكربونات (Calcium Carbonate Deposits)
الحجر الجيري (Limestone)
الدولوميت (Dolomite/ Dolostone)
الفرق بين الحجر الجيري (Limestone) و الدولوميت (Dolomite/ Dolostone)
استخدمات الحجر الجيري
السن المستخدم فى الاغراض المدنية
سن الأسفلت (Road or Asphalt Aggregates):
سن جابرو (Gabbro Aggregates)
سن بازالت (Basalt Aggregates)
سن الدولوميت (Dolomite/Dolostone Aggregates)
سن الشيرت (Chert Aggregates)
السن المستخدم فى الخرسانة وأغراض البناء (Aggregate Used in Concrete & Building Purposes)
الفرق بين الزلط (Flint/Chert) و السن (Aggregate)...!
الأقضلية بين استخدام الزلط (Flint/Chert) و السن (Aggregate) فى الخرسانة وأغراض البناء
This document is a presentation by 10 students on fluvial channels. It defines a fluvial channel as the pathway through which rivers flow. It describes the different stages and forms of river channels, including straight, anastomosing, braided, and meandering. It discusses the deposits associated with braided and meandering rivers, including point bars and braided bars. Finally, it notes the economic importance of fluvial deposits as aquifers, petroleum reservoirs, and hosts for minerals.
Porphyry copper deposits are the world's most important source of copper and molybdenum. They form due to fluids released from subducting tectonic plates melting the mantle and generating magmas. Porphyry deposits are large, low-grade deposits centered around intrusive porphyry stocks. They are characterized by vein-hosted and disseminated sulfide mineralization within zones of hydrothermal alteration surrounding the intrusion. Porphyry deposits are mined via large-scale open-pit and underground block caving methods due to their great size and low grades.
Sulfide mineralization are the main resource for exploiting Pb, Zn, and Cu metals in Egypt.
Sulfide mineralization is represented by four sulfide types of the different setting, lithology and ages, namely:
i) Lead-Zinc sulphide Deposits
ii) Cu-NiCo sulphide Deposits
This type of mineralization is well represented in Abu Swayel in South Eastern Desert. The ore is closely related to mafic-ultramafic and gabbro of ophiolitic rocks.
iii) Cu-Ni sulphide deposits
This type of mineralization occurs in layered mafic-ultramafic intrusions like gabbro rocks at Akarm and El Geneina .
iv) Stratiform Massive Sulphide (Zn-Cu-Pb) Deposits
This type of mineralization is represented by a group of small lenses associated with talc deposits in South Eastern Desert at: Um Samuki, Helgit, Maakal, Atshan, Darhib, Abu Gurdi, and Egat.
Residual mineral deposits; Laterites; Laterite Profile; Laterisation system; Laterite/Bauxite Conditions; Laterite-type Bauxite, Constitution of Bauxite, Types of deposits; Origin and Mode of formation; Clay (Kaolinite) Deposits; Nickel Laterite Deposits; Mineralogy and Types of lateritic nickel ore deposits; World Nickel Laterite Deposits; Processing of Ni Laterites; Example: Ni-laterites, Ni in soils in east Albania
Lakeland Resources Inc. (TSXv: LK) (FSE: 6LL) geologist Darren L. Smith, M.Sc., P.Geol. recently gave the attached presentation investor groups in Europe. His presentation covered the technical aspects of uranium exploration in the Athabasca Basin, Saskacthewan and was titled "Athabasca Basin Uranium."
The document discusses mine waste issues at the Sukari Gold Mine in the Eastern Desert of Egypt. It notes that mine wastes from gold mining and processing contain hazardous substances like heavy metals, acids, and chemicals that can pollute the surrounding environment if not properly disposed of and monitored. The wastes are produced from mining activities, mineral processing plants, and smelting and are in the forms of solids, liquids, and gases. At Sukari, waste rock is disposed of in rock dumps, but these are not sealed and allow contaminated water to seep into surface water and groundwater, causing acid mine drainage issues. Waste water from processing contains reagents, solvents, acids, and contaminated groundwater and needs treatment
Rivers erode, transport, and deposit material as they flow across the landscape. There are four main types of erosion by rivers: abrasion, attrition, hydraulic action, and solution. Transportation occurs through traction, saltation, suspension, and solution. Deposition takes place when the river's speed or volume decreases, such as when entering a lake or plain. A river's work depends on its energy, which is determined by the volume of water and flow speed according to the gradient.
Aggregate Used in Concrete & Building Purposes; صخورالصوان (Chert)
درنات او عقيدات الشيرت(Nodular or Concretion Cherts)
زلط الطواحين (Mill chert)
الشيرت الطبقى (Bedded Cherts )
رواسب الكالسيوم الكربونات (Calcium Carbonate Deposits)
الحجر الجيري (Limestone)
الدولوميت (Dolomite/ Dolostone)
الفرق بين الحجر الجيري (Limestone) و الدولوميت (Dolomite/ Dolostone)
استخدمات الحجر الجيري
السن المستخدم فى الاغراض المدنية
سن الأسفلت (Road or Asphalt Aggregates):
سن جابرو (Gabbro Aggregates)
سن بازالت (Basalt Aggregates)
سن الدولوميت (Dolomite/Dolostone Aggregates)
سن الشيرت (Chert Aggregates)
السن المستخدم فى الخرسانة وأغراض البناء (Aggregate Used in Concrete & Building Purposes)
الفرق بين الزلط (Flint/Chert) و السن (Aggregate)...!
الأقضلية بين استخدام الزلط (Flint/Chert) و السن (Aggregate) فى الخرسانة وأغراض البناء
This document is a presentation by 10 students on fluvial channels. It defines a fluvial channel as the pathway through which rivers flow. It describes the different stages and forms of river channels, including straight, anastomosing, braided, and meandering. It discusses the deposits associated with braided and meandering rivers, including point bars and braided bars. Finally, it notes the economic importance of fluvial deposits as aquifers, petroleum reservoirs, and hosts for minerals.
Porphyry copper deposits are the world's most important source of copper and molybdenum. They form due to fluids released from subducting tectonic plates melting the mantle and generating magmas. Porphyry deposits are large, low-grade deposits centered around intrusive porphyry stocks. They are characterized by vein-hosted and disseminated sulfide mineralization within zones of hydrothermal alteration surrounding the intrusion. Porphyry deposits are mined via large-scale open-pit and underground block caving methods due to their great size and low grades.
Sulfide mineralization are the main resource for exploiting Pb, Zn, and Cu metals in Egypt.
Sulfide mineralization is represented by four sulfide types of the different setting, lithology and ages, namely:
i) Lead-Zinc sulphide Deposits
ii) Cu-NiCo sulphide Deposits
This type of mineralization is well represented in Abu Swayel in South Eastern Desert. The ore is closely related to mafic-ultramafic and gabbro of ophiolitic rocks.
iii) Cu-Ni sulphide deposits
This type of mineralization occurs in layered mafic-ultramafic intrusions like gabbro rocks at Akarm and El Geneina .
iv) Stratiform Massive Sulphide (Zn-Cu-Pb) Deposits
This type of mineralization is represented by a group of small lenses associated with talc deposits in South Eastern Desert at: Um Samuki, Helgit, Maakal, Atshan, Darhib, Abu Gurdi, and Egat.
Residual mineral deposits; Laterites; Laterite Profile; Laterisation system; Laterite/Bauxite Conditions; Laterite-type Bauxite, Constitution of Bauxite, Types of deposits; Origin and Mode of formation; Clay (Kaolinite) Deposits; Nickel Laterite Deposits; Mineralogy and Types of lateritic nickel ore deposits; World Nickel Laterite Deposits; Processing of Ni Laterites; Example: Ni-laterites, Ni in soils in east Albania
Lakeland Resources Inc. (TSXv: LK) (FSE: 6LL) geologist Darren L. Smith, M.Sc., P.Geol. recently gave the attached presentation investor groups in Europe. His presentation covered the technical aspects of uranium exploration in the Athabasca Basin, Saskacthewan and was titled "Athabasca Basin Uranium."
This document provides an overview of uranium geology and exploration in the Athabasca Basin region of northern Saskatchewan, Canada. It discusses the characteristics of uranium, describes the geology and deposit types in the Athabasca Basin, and outlines exploration techniques used to discover deposits. Key points include: Uranium is a radioactive element commonly found in pitchblende deposits; the Athabasca Basin hosts high-grade unconformity-associated uranium deposits due to its unique geological history and features; and discoveries are made through a combination of geophysical surveys, geochemical sampling, and drilling to follow up on anomalies.
The document discusses mineral resources that are found in the ocean or were originally deposited under marine conditions. It describes how oceans contain vast quantities of dissolved materials and minerals due to geological processes. Currently, direct extraction from the ocean is limited but includes salt, magnesium, placer deposits, and fresh water. However, as terrestrial deposits become exhausted, exploitation of ancient ocean deposits and extraction directly from the sea will likely increase to meet growing demand. The document outlines some of the major mineral resources found in oceans or deposited from oceans, such as salt, potassium, magnesium, sand and gravel, limestone, gypsum, manganese nodules, phosphorites, and metal deposits associated with seafloor vents.
1. The field report summarizes the geological field trip to the Malakand area. Key rock units studied included lacustrine fluvial deposits, various metasedimentary rocks like graphitic schist, talc schist, quartz-mica schist, green schist, garnet-mica schist, and banded marble. Igneous rocks like the Malakand granite were also examined.
2. Structural features like sedimentary and amphibolite dykes cutting through the rock units were observed. Metamorphism ranged from green schist facies to amphibolite facies near the Malakand granite contact.
3. The field trip provided an
This document discusses ore deposits and the fluids involved in their formation. It covers five main types of ore-bearing fluids: 1) magmas and magmatic fluids, 2) meteoric waters, 3) connate waters, 4) fluids associated with metamorphic processes. It then discusses the migration of ore-bearing fluids through rocks, noting that permeability and porosity allow fluids to circulate over long periods of time. Metals can also migrate in the colloidal state within fluids. The document provides an overview of the key fluids and processes involved in forming various ore deposit types.
The interview summarizes announcements from Soltera Mining Corp regarding assay results from their El Torno gold property in Argentina. One reported low gold values from weathered surface material not suitable for production. Another reported high gold values from vein samples, including 1.5m at 376g/t gold, confirming a gold-rich zone. Goldlake will invest $900k by June to support exploration of main vein targets. Next steps are detailed mapping, sampling and geophysics to define drill targets for the next field season starting in September.
The document summarizes exploration work done on the Major Hart property, which contains a pluton that shows highly anomalous stream sediment geochemistry indicative of a rare-element granite. Several key points are made:
1) Stream samples from the property contain anomalies of rare earth elements, tin, tantalum, and tungsten that are amongst the highest levels in BC.
2) The pluton shares similar geochemistry with deposits elsewhere that contain rare earth element pegmatites and tin mines.
3) Distal dykes from the pluton are associated with high-grade gold veins, and the property has potential for contact-related gold and emerald deposits.
4) The property
The interview summarizes assay results from Soltera Mining Corp's El Torno gold project in Argentina. Initial testing of eluvial deposits found insufficient gold levels for commercial production. However, further sampling of the main vein system found much higher gold values, including channels up to 6.5 meters wide with 6.2-8.8 g/t gold. These confirm a gold-rich zone along the vein and indicate potential for future production. Goldlake Resources agreed to fund exploration of the major vein targets. Next steps include detailed mapping and sampling along the 14 km vein system, geophysics, and an initial drill program later in 2021 to define targets.
This document provides an overview of the geology, mineral occurrences, and previous exploration work in the Prospecting License C-75 area in Guyana. The area consists of Lower Proterozoic volcanic and sedimentary rocks overlain by younger sediments. It has seen historical small-scale gold and diamond mining. Recent work included mapping geology from air photos and satellite data, identifying structures, sampling rocks and minerals, and interpreting aeromagnetic data to define lithologies and structures. Gold and diamond occurrences are present both within bedrock and in alluvial deposits.
The Olympic Dam deposit in South Australia contains huge reserves of copper, uranium, gold, and silver. It is hosted by the Burgoyne batholith within the Olympic Dam Breccia Complex, which formed from repeated brecciation and hematite alteration over 1588 million years. BHP Billiton currently mines the deposit, producing around 200,000 tons of copper and 3,500 tons of uranium oxide annually from 9 million tons of ore. The deposit remains an important economic resource due to its large size and potential for further expansion.
1) Immobile element analysis was used to identify volcanic rock types at the Kristineberg VMS deposit in Sweden, despite extensive alteration and metamorphism. This helped correlate units between drill holes.
2) A chemostratigraphic sequence was determined, with rhyolite A south of lens B and rhyolite X north of lens A, separated by andesitic to rhyodacitic rocks hosting the lenses.
3) Calculated alterations show strong asymmetric envelopes up to 50m from lenses, with additions of Mg, Fe, and Si losses.
The owner of a gold proejct in Mashonaland West province of Zimbabwe is seeking for investors to help fund sampling and drilling of a gold project area in the gold rich area of Sanyati. Excellent potential. The owner is a seasoned Geologist himself.
This document discusses mineral and energy resources. It begins by describing how early humans began using minerals like flint and metals over 20,000 years ago. It then covers the formation of different types of mineral deposits including hydrothermal deposits formed from hot aqueous solutions, magmatic deposits within igneous rocks, and sedimentary deposits from precipitation or weathering. Specific examples of important mineral deposits are provided for different minerals. The document concludes by discussing classifications of useful mineral substances and various energy resources.
The document summarizes geology and geophysics research on the Lisle-Golconda goldfield in northeast Tasmania. It finds that over 95% of gold production in the region came from alluvial deposits, with the primary hard rock source unknown. Studies of gold grains indicate much of the alluvial gold is of secondary origin, having precipitated from groundwater within sediments. Geophysical data helps constrain the subsurface distribution of granitic intrusions spatially associated with many gold occurrences in the field.
This document discusses different types of drainage sediments that can contain anomalies indicative of mineral deposits: sediments from springs and seepage areas, active stream sediments, floodplain sediments, and lake sediments. It describes how metals may be incorporated into these sediments from mineralized bedrock or transported by water. Drainage sediments are useful in geochemical exploration for mining because they allow large areas to be surveyed as sediments are carried by surface and groundwater flows.
Uranium Deposits
Uranium is a very dense metal which can be used as an abundant source of concentrated energy. It occurs in most rocks in concentrations of 2 to 4 parts per million and is as common in the earth's crust as tin, tungsten and molybdenum.
.
There are three main types of uranium deposits including 1. unconformity-type deposits, 2. paleoplacer deposits and 3. sandstone-type (roll front) deposits (Figure 1). Sandstone-type deposits are abundant in sedimentary rocks of the Colorado Plateau and found on the Navajo Nation. This type of uranium deposit is easier and cheaper to mine than the other types because the uranium is found near the surface of the Earth. These deposits formed when oxidized groundwater that had leached uranium from surface rocks flowed down into aquifers, where it was reduced to precipitate uraninite, the primary ore mineral of uranium. In some deposits, like those found on the Navajo Nation, reduction took place along curved zones know as roll-fronts, which represent the transition from oxidized to reduced conditions in the aquifer.
This document provides information on diamond geology, including the classification and origins of diamond deposits. It discusses primary kimberlite and lamproite deposits as well as secondary alluvial and marine deposits. It also describes some of the major diamond mining areas in South Africa, including both primary kimberlite mines and secondary alluvial deposits. Worldwide, economically significant diamond deposits are primarily found in regions with Archean craton geology, which provides the appropriate pressure and temperature conditions for diamond formation and preservation.
The Royalle property is located 175 km north of Vancouver in central British Columbia, near the historic Bralorne-Pioneer gold mining camp. The property consists of three contiguous mineral claims covering 2,620 hectares. Exploration over the years has identified several gold and copper-tungsten zones, including the Upper Piebiter gold zone and the Chalco copper-tungsten zone. Recent geophysical surveys have outlined structures prospective for porphyry and epithermal mineralization. The property remains underexplored and offers potential for the discovery of bulk tonnage gold deposits and porphyry-related mineralization.
This document summarizes sedimentary ore deposits, specifically banded iron formations (BIF). It discusses the processes that form different types of BIF, including Algoma and Superior types, as well as their geologic time distribution. The document also explains the role of microbial communities in the deposition of iron minerals and formation of BIF layers through anoxic iron redox cycling, including phototrophic Fe(II) oxidation and nitrate-dependent Fe(II) oxidation mediated by bacteria. Overall, the document provides an overview of the genesis and microbial influences on the formation of important economic BIF deposits in sedimentary environments.
In this presentation we discuss cobalt crusts, its classification, Occurrence and Distribution, Formation, Texture, Mineralogy, Scope for future mining and exploration.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
This document provides an overview of uranium geology and exploration in the Athabasca Basin region of northern Saskatchewan, Canada. It discusses the characteristics of uranium, describes the geology and deposit types in the Athabasca Basin, and outlines exploration techniques used to discover deposits. Key points include: Uranium is a radioactive element commonly found in pitchblende deposits; the Athabasca Basin hosts high-grade unconformity-associated uranium deposits due to its unique geological history and features; and discoveries are made through a combination of geophysical surveys, geochemical sampling, and drilling to follow up on anomalies.
The document discusses mineral resources that are found in the ocean or were originally deposited under marine conditions. It describes how oceans contain vast quantities of dissolved materials and minerals due to geological processes. Currently, direct extraction from the ocean is limited but includes salt, magnesium, placer deposits, and fresh water. However, as terrestrial deposits become exhausted, exploitation of ancient ocean deposits and extraction directly from the sea will likely increase to meet growing demand. The document outlines some of the major mineral resources found in oceans or deposited from oceans, such as salt, potassium, magnesium, sand and gravel, limestone, gypsum, manganese nodules, phosphorites, and metal deposits associated with seafloor vents.
1. The field report summarizes the geological field trip to the Malakand area. Key rock units studied included lacustrine fluvial deposits, various metasedimentary rocks like graphitic schist, talc schist, quartz-mica schist, green schist, garnet-mica schist, and banded marble. Igneous rocks like the Malakand granite were also examined.
2. Structural features like sedimentary and amphibolite dykes cutting through the rock units were observed. Metamorphism ranged from green schist facies to amphibolite facies near the Malakand granite contact.
3. The field trip provided an
This document discusses ore deposits and the fluids involved in their formation. It covers five main types of ore-bearing fluids: 1) magmas and magmatic fluids, 2) meteoric waters, 3) connate waters, 4) fluids associated with metamorphic processes. It then discusses the migration of ore-bearing fluids through rocks, noting that permeability and porosity allow fluids to circulate over long periods of time. Metals can also migrate in the colloidal state within fluids. The document provides an overview of the key fluids and processes involved in forming various ore deposit types.
The interview summarizes announcements from Soltera Mining Corp regarding assay results from their El Torno gold property in Argentina. One reported low gold values from weathered surface material not suitable for production. Another reported high gold values from vein samples, including 1.5m at 376g/t gold, confirming a gold-rich zone. Goldlake will invest $900k by June to support exploration of main vein targets. Next steps are detailed mapping, sampling and geophysics to define drill targets for the next field season starting in September.
The document summarizes exploration work done on the Major Hart property, which contains a pluton that shows highly anomalous stream sediment geochemistry indicative of a rare-element granite. Several key points are made:
1) Stream samples from the property contain anomalies of rare earth elements, tin, tantalum, and tungsten that are amongst the highest levels in BC.
2) The pluton shares similar geochemistry with deposits elsewhere that contain rare earth element pegmatites and tin mines.
3) Distal dykes from the pluton are associated with high-grade gold veins, and the property has potential for contact-related gold and emerald deposits.
4) The property
The interview summarizes assay results from Soltera Mining Corp's El Torno gold project in Argentina. Initial testing of eluvial deposits found insufficient gold levels for commercial production. However, further sampling of the main vein system found much higher gold values, including channels up to 6.5 meters wide with 6.2-8.8 g/t gold. These confirm a gold-rich zone along the vein and indicate potential for future production. Goldlake Resources agreed to fund exploration of the major vein targets. Next steps include detailed mapping and sampling along the 14 km vein system, geophysics, and an initial drill program later in 2021 to define targets.
This document provides an overview of the geology, mineral occurrences, and previous exploration work in the Prospecting License C-75 area in Guyana. The area consists of Lower Proterozoic volcanic and sedimentary rocks overlain by younger sediments. It has seen historical small-scale gold and diamond mining. Recent work included mapping geology from air photos and satellite data, identifying structures, sampling rocks and minerals, and interpreting aeromagnetic data to define lithologies and structures. Gold and diamond occurrences are present both within bedrock and in alluvial deposits.
The Olympic Dam deposit in South Australia contains huge reserves of copper, uranium, gold, and silver. It is hosted by the Burgoyne batholith within the Olympic Dam Breccia Complex, which formed from repeated brecciation and hematite alteration over 1588 million years. BHP Billiton currently mines the deposit, producing around 200,000 tons of copper and 3,500 tons of uranium oxide annually from 9 million tons of ore. The deposit remains an important economic resource due to its large size and potential for further expansion.
1) Immobile element analysis was used to identify volcanic rock types at the Kristineberg VMS deposit in Sweden, despite extensive alteration and metamorphism. This helped correlate units between drill holes.
2) A chemostratigraphic sequence was determined, with rhyolite A south of lens B and rhyolite X north of lens A, separated by andesitic to rhyodacitic rocks hosting the lenses.
3) Calculated alterations show strong asymmetric envelopes up to 50m from lenses, with additions of Mg, Fe, and Si losses.
The owner of a gold proejct in Mashonaland West province of Zimbabwe is seeking for investors to help fund sampling and drilling of a gold project area in the gold rich area of Sanyati. Excellent potential. The owner is a seasoned Geologist himself.
This document discusses mineral and energy resources. It begins by describing how early humans began using minerals like flint and metals over 20,000 years ago. It then covers the formation of different types of mineral deposits including hydrothermal deposits formed from hot aqueous solutions, magmatic deposits within igneous rocks, and sedimentary deposits from precipitation or weathering. Specific examples of important mineral deposits are provided for different minerals. The document concludes by discussing classifications of useful mineral substances and various energy resources.
The document summarizes geology and geophysics research on the Lisle-Golconda goldfield in northeast Tasmania. It finds that over 95% of gold production in the region came from alluvial deposits, with the primary hard rock source unknown. Studies of gold grains indicate much of the alluvial gold is of secondary origin, having precipitated from groundwater within sediments. Geophysical data helps constrain the subsurface distribution of granitic intrusions spatially associated with many gold occurrences in the field.
This document discusses different types of drainage sediments that can contain anomalies indicative of mineral deposits: sediments from springs and seepage areas, active stream sediments, floodplain sediments, and lake sediments. It describes how metals may be incorporated into these sediments from mineralized bedrock or transported by water. Drainage sediments are useful in geochemical exploration for mining because they allow large areas to be surveyed as sediments are carried by surface and groundwater flows.
Uranium Deposits
Uranium is a very dense metal which can be used as an abundant source of concentrated energy. It occurs in most rocks in concentrations of 2 to 4 parts per million and is as common in the earth's crust as tin, tungsten and molybdenum.
.
There are three main types of uranium deposits including 1. unconformity-type deposits, 2. paleoplacer deposits and 3. sandstone-type (roll front) deposits (Figure 1). Sandstone-type deposits are abundant in sedimentary rocks of the Colorado Plateau and found on the Navajo Nation. This type of uranium deposit is easier and cheaper to mine than the other types because the uranium is found near the surface of the Earth. These deposits formed when oxidized groundwater that had leached uranium from surface rocks flowed down into aquifers, where it was reduced to precipitate uraninite, the primary ore mineral of uranium. In some deposits, like those found on the Navajo Nation, reduction took place along curved zones know as roll-fronts, which represent the transition from oxidized to reduced conditions in the aquifer.
This document provides information on diamond geology, including the classification and origins of diamond deposits. It discusses primary kimberlite and lamproite deposits as well as secondary alluvial and marine deposits. It also describes some of the major diamond mining areas in South Africa, including both primary kimberlite mines and secondary alluvial deposits. Worldwide, economically significant diamond deposits are primarily found in regions with Archean craton geology, which provides the appropriate pressure and temperature conditions for diamond formation and preservation.
The Royalle property is located 175 km north of Vancouver in central British Columbia, near the historic Bralorne-Pioneer gold mining camp. The property consists of three contiguous mineral claims covering 2,620 hectares. Exploration over the years has identified several gold and copper-tungsten zones, including the Upper Piebiter gold zone and the Chalco copper-tungsten zone. Recent geophysical surveys have outlined structures prospective for porphyry and epithermal mineralization. The property remains underexplored and offers potential for the discovery of bulk tonnage gold deposits and porphyry-related mineralization.
This document summarizes sedimentary ore deposits, specifically banded iron formations (BIF). It discusses the processes that form different types of BIF, including Algoma and Superior types, as well as their geologic time distribution. The document also explains the role of microbial communities in the deposition of iron minerals and formation of BIF layers through anoxic iron redox cycling, including phototrophic Fe(II) oxidation and nitrate-dependent Fe(II) oxidation mediated by bacteria. Overall, the document provides an overview of the genesis and microbial influences on the formation of important economic BIF deposits in sedimentary environments.
In this presentation we discuss cobalt crusts, its classification, Occurrence and Distribution, Formation, Texture, Mineralogy, Scope for future mining and exploration.
Similar to 1- Gold and rivers 2017 - (eng version) - [Oberto, 2018] (20)
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
2. Secondary gold deposits and fluvial dynamics
• A short useful guide for gold prospecting along river banks
with or without the presence of bedrock.
08/03/2018 2
3. The author
08/03/2018 3
Matteo Oberto is an Italian
amateur gold prospector with
knowledge in geological
sciences as part of his
geology degree.
He is active on the web as a
promoter of many products
and he has written guides on
prospecting gold and gems.
4. 1 ) Main locations of gold deposits along
rivers
08/03/2018 4
Contents:
- Imbrications & natural traps;
- Superficial enrichment;
- Presence and influence of bedrock;
- Fluvial traps & boulder enrichments;
- How to find a pay streak;
- How to work a pay streak;
- Prospecting the river banks;
- Conclusive notes and contacts
5. 1 a – Imbrications & natural traps;
08/03/2018 5
Blue arrow: main water current flow during the flood;
Red rectangles: Major dimensional axes of clasts , showing the imbrication structure;
Purple triangles: Main gold enrichment, the main one is behind the final cobble (the large violet triangle).
6. 1 b – Superficial enrichment (Surface flood enrichment)- an example
08/03/2018
6
The best place to look for gold is usually close to the surface, due to its accessibility and readiness to recover. The first
30 – 40 cm are the best for finding good gold, which comes from the last flood. It is wrong to automatically assume
that gold is greater in quantity with depth - however, sometimes this case holds true, for example if there is overburden on
that gold deposit or if there have been many prospectors in that area.
7. Is it possible to pick gold out from other sediments by hand?
08/03/2018
7
The technique known as “gold picking” is rarely possible, in fact gold will usually be collected with
equipment (pan, sluice, etc) and traces of gold can be found inside the concentrate of heavy
minerals or by panning. Instead of pick ing gold by hand, it would be better if the prospector learns how to observe the
environment. Other factors to keep in mind are:
the presence of big boulders, imbraction structures, green or dark grey – black cobbles, etc.
8. 1 c – The concentration of big boulders
08/03/2018 8
On the left, you can see that the boulder
can have a 2 metre long major axis.
In respect to the adjacent clasts and their average
dimensions , the boulders are really
concentrated there. These are often good spots
for attaining large amounts of gold.
9. 08/03/2018 9
The alluvional material concentrated among the boulders
will not be easier to prospect or dig out but it is often good quality, in
terms of the quantity of gold content and heavy minerals.
The prospector should remember that if there isn’t any kind of
gold in the river, it won’t be trapped by any fluvial traps.
Examples of heavy minerals: Magnetite, garnet, hematite, gold, corindum, etc.
Example of heavy antrophic materials found with gold: Tin shots, metallic rubbish, etc.
The prospect should be concentrated closer to bigger boulders
10. Pay attention to the superficial wash of light sediments (clay, silt, sand)
08/03/2018 10
As the reader can see, in the left picture there is a real case where the
blue portion is made of washed clasts and there isn’t any sandy or silty material.
Below that level, it is concentrated by the wash itself and the heaviest portion
of the sediment collected among the clasts.
In this case, the prospector should move the upper clasts away in order to dig the
best portion of sediment.
Clast cover
Enrichment due to the wash
11. 1 d – The presence and influence of bedrock
08/03/2018 11
Water on clay
bedrock
The alluvional auriferous deposit could be positioned above a bedrock, which
could contain gold usually in the cracks on the top or along local depressions.
The bedrock could be:
- Bedrock made by rock (this will be discussed in depth in another guide);
- Bedrock made by clay and silt (we will focus on this aspect in this guide);
Both cases are good for gold enrichment in fluvial deposits above the
bedrock. Usually, the sediments above the bedrock are richer than more distant ones.
It’s also true that the river doesn’t carry any gold and you won’t find any gold on the
bedrock.
In the left picture, the water on the clay bedrock is visible.
This works as an impermeable limit, and water has to accumulate on it.
12. Detail of an alluvial deposit
08/03/2018 12
Quaternary deposits may get altered during time and they could become
a sort of bedrock themselves, useful for gold deposition.
In the left picture, the reader can see a very altered alluvial deposit set above
the real regional clay bedrock, called “Villafranchiano»”
The reader should also be aware of the clasts inside the altered fluvial deposit.
They appear white or white grey and are quarzites, which are usually
very difficult to be altered. The light brown coloration of the deposit is due to
the high content of clay, a product of alteration.
13. Rivarolo (near Turin), a real case of clay bedrock
- Where are the best auriferous levels set?
08/03/2018 13
Clay bedrock (Villafranchiano)
Alluvial altered
deposit
Quaternary alluvial deposit
The quaternary alluvial deposit is the sum of several erosion episodes during past floods. The gold
present in the sediments would be mobilized if the erosion takes place in the floods- the successive
deposition and sedimentation could generate a local enrichment.
C
b
B
a
A
C – Gold has been found along the most depressed path along the river bed or located along pay streaks;
b – Best auriferous gravel level sets above B. It’s just 30 cm thick;
B – Gold has been found fine and dispersed;
a – Nice auriferous gravel level sets above A. It contains also chunky gold and flakes;
A – Gold has been found only in the superficial cracks or local erosion depressions.
Simplified profile
transversal ( respect the
flow direction)
d
14. 08/03/2018 14
Simplified model of chronological events
Auriferous level a genesis -> deposition of deposit B -> Auriferous level b genesis
Partial erosion of B-> auriferous level d genesis -> deposition of deposit C
The reader should note that gold is present in both deposits B and C but the best layers of heavy minerals are set above
the deposits themselves.
NB: B is only locally conserved.
Simplified transverse profile
(respect the main flow direction)
Deposit A genesis
Clay bedrock (Villafranchiano)
Alluvial altered
deposit
Quaternary alluvial depositC
b
B
a
A
d
15. Evidence of clay bedrock outcrop
08/03/2018 15
Deposit C
Clay bedrock “Villafranchiano»”
Auriferous level c
The outcrop is steep and so the sandy material is washed away and the bigger clasts are concentrated in the lowest part
of the picture.
16. 08/03/2018 16
C deposit
B deposit
A deposit (partially buried)
Auriferous level a
Auriferous level b
Example of an outcrop where you can see the differences among the deposits
Lateral b pass to d.
18. Other evidence of the outcrops of the deposits A (red) and B (yellow)
08/03/2018 18
19. 08/03/2018 19
C deposit
B deposit
Auriferous level b
Detail of the alluvial origin of deposit B. There is also the presence
of poligenic cobbles, some of these are totally altered and only the shapes are
visible.
Quarzite, cobble with a good grade of
roundness, index of river transport.
20. 08/03/2018 20
Above picture: detail of the oxide patterns on the
cobbles, index of fluid migration, in this case, above the
impermeable units (clay bedrock);
Right picture: detail of completely altered gneiss cobble
21. 08/03/2018 21
Auriferous level b
The red area is the exploited portion of the auriferous level b,
the reader should be aware that the correct exploitation of that level
has involved also the upper part of deposit B and the lower part of C.
Cracks in B and depressions have been exploited preferentially.
23. A few conclusions from real cases
08/03/2018 23
- The auriferous levels a and b are usually richer than other deposits, they also contain flakes;
- Richness of level a > level b;
- Richness of the deposits: C >> B > A;
- Exclusive alluvial origin of the enrichment (erosion & deposition);
- Presence of big boulders or cobbles at the base of B and C due to the normal river sedimentation and presence of
evident imbricated structures;
- At the bottom of local paleo river erosion depressions, there are the presence of oxides of Mn and Fe due to the
circulation of mineralized fluids;
- Digging in the right locations, the average quantity of gold found per day is usually around 0.1 – 0.8 gram.
24. 1 e - Fluvial traps & boulder enrichments
08/03/2018 24
Blue arrow: main water direction during the
flood;
Red triangle: gold enriched area;
The two cases are different-
In A, the reader can see a good spot for gold
while in B someone has worked on that spot
in the past.
In A, all the dimensions of clasts are present,
such as gravel, sand, silt, and some cobbles.
In B there is a local depression with the
majority of components made of cobbles or
washed gravel.
NB: Exceptional floods are able to change the river pattern and enrich these types of traps.
A B
25. Simplified model of gold enrichment behind and in front of boulders (flow obstacles)
08/03/2018
Materiale didattico gratuito e condivisibile a seguito di
citazione autore: Matteo Oberto 2017.
25
Obstacle
Main direction of
the river flow
Obstacle major axis:
It’s set up orthogonal with respect to the obstacle.
The obstacle makes a pertubation in the river flow and in front and behind
itself there will be low velocity zones, where gold may be collected.
Vision from above
26. Gold enrichment positions
08/03/2018
Materiale didattico gratuito e condivisibile a seguito di
citazione autore: Matteo Oberto 2017.
26
Obstacle
Frontal enrichment
Posterior main enrichment
Flow direction
Erosion wingsErosion wings
Along erosion wings the alluvial material, during floods, is eroded. Part of it will be collected in the posterior enrichment.
Vision from above
27. Model for gold enrichment
08/03/2018
Materiale didattico gratuito e condivisibile a seguito di
citazione autore: Matteo Oberto 2017.
27
Obstacle
Fluvial bed
Frontal enrichment
Posterior enrichment
Due to the velocity pertubation there will be two main portion of low velocity thanks to the vortices. Heavy minerals
will be collected in the frontal and posterior enrichment areas, while the lighter particles will be washed away.
Those vorteces work as concentrators, so heavy material just has to be concentrated during time and floods while lighter
stuff will be transported away thank the water flow. The richest portion are usually ubicated close to the boulder itself.
Lateral view
28. Where can I find gold?
08/03/2018
Materiale didattico gratuito e condivisibile a seguito di
citazione autore: Matteo Oberto 2017.
28
Obstacle
Fluvial bed
Frontal enrichment
Posterior enrichment
Richer portion and
larger gold particles
(Red portion)
Finer and lower gold quantityFiner and lower gold quantity
Lateral view
29. Frontal and posterior enrichment
08/03/2018
Materiale didattico gratuito e condivisibile a seguito di
citazione autore: Matteo Oberto 2017.
29
B
A
B – Frontal gold enrichment;
A – Posterior gold enrichment;
In this case, someone has already
obtained the best material.
30. Imbrications as local obstacles
08/03/2018 30
The river bed works as a sluice in some parts, in fact every clast, cobble and boulder may act as a local gold trap. In this case
the reader can see how few cobbles have been set up imbricated. The purple portion is the main region for gold.
31. 08/03/2018 31
Big obstacles
These tend to generate a posterior enrichment bigger
than the frontal one during floods.
In the picture, the posterior enrichment has been
buried by lighter sediments, which became sediments during the
final phases of the flood. Generally these don’t contain gold.
The elongation of the posterior enrichment shows the
direction and the verse of the water during the formation.
32. 08/03/2018 32
Another difference is how the posterior enrichment shows us
the direction and the verse of the water current.
In this case the last phases didn’t cover the good spots, in fact there
isn’t a sandy layer on the enrichment as we saw before.
33. 08/03/2018 33
Example of a posterior enrichment exploited by a prospector. There is
a general anbsence of the gravel portion, removed for washing.
It’s useful to note that the posterior enrichment should be greater than the
frontal one, and richer also.
Just sometimes, in the frontal enrichment there is more gold, compared to
the posterior enrichment.
34. 08/03/2018 34
Example of posterior enrichment exploitation.
In this case, the reader should note that under the boulder
there was a clay bedrock, in a concentrated layer.
An accurate cleaning of the above portion (5-10cm) can
show nice surprises.
35. 1 f – How to find a pay streak
08/03/2018 35
Alluvial simple pay streak
Floods may create good spotted enrichment just after
concave portions of the river pattern. Along concave curves
the river force can erode big amounts of sediments and the
sedimentation just after, makes a pay streak.
This is known as simple pay streak, when just one
big flood permanently alters the river pattern.
Pay streak body
Cappello
limoso
Depressione interna
«core», porzione più ricca,
semplificata con un ellisse.
An alluvial simple pay streak is generated by one exceptional
flood event.
Vision from above
36. 08/03/2018 36
General gold distribution along a single simple pay streak (top view image)
The reader should be aware that this image is a simplification of reality due to the several processes that could have been
important for the pay streak or its past.
Blue portion: Simple pay streak
Light green: presence of fine gold;
Green: presence of medium gold;
Dark green: presence of coarse gold;
37. 08/03/2018 37
Identification of the pay streak
core by satellite images.
Modern tools like satellite images
are beneficial to prospectors in
finding good locations to search for gold.
The concave fluvial margin
provides gold during floods due to
its erosion by the force of the river flow.
38. 08/03/2018 38
Alluvial pay streaks are used to be found
just after a concave fluvial margin.
They are ephemeral entities.
Some pay streaks may be eroded or buried or
became enriched.
Among important floods, the pay streak may be locally
eroded and some portion will get enriched. This is the
origin of complex pay streaks.
39. 08/03/2018 39
Complex alluvial pay streaks
In a complex alluvial pay streak there are many cores,
so the prospector can find many good locations for finding
gold. Usually, the different cores are ubicated along the
closer margin of the pay streak with respect to the river.
The reader should be aware about what we said before:
local enrichments by obstacles are active in this context, so
boulders may locally enrich a portion of gold.
40. 08/03/2018 40
Morphology of a complex alluvial pay streak.
As we noted before, a simple alluvial pay streak may be created by an important flood event. Among many smaller floods
the same pay streak could be partially mobilized and some portions get richer. In this way along the same actual
pay streak, the prospector can work several cores (usually closer the river course).
It’s useful to note that the bigger gold should be present majorly in the first and the ancient core. An exception should
be noted for flat gold, which can move away and be found in the last cores (the youngest ones).
A real case of complex pay streak
Green cores:
Dark: older
Light: young
41. 08/03/2018 41
Complex alluvial pay straeks, a detailed look
Here is an example of the alluvial pattern of several
complex pay streaks along the same
river. The reader should note that after
an erosion curve, there is usually a
sedimentation area.
Complex alluvial pay streaks
Grey arrow: sedimentation
Blue arrow: erosion
The main concept is that among several notable floods there were several patterns of simple pay streaks. Among two
important flood events there is the time to create few complex pay streakspatterns by the partial erosion and
concentration of past simple pay streaks.
42. 08/03/2018 42
Other types of gold enrichment
When the river section gets larger, gold may be concentrated
When the river path gets larger, the water
speed suffers a decrease and so it would
boost the sedimentation process.
43. 08/03/2018 43
Hidden pay streaks
They are ubicated along old river paths, usually called abandoned meandres or similar ones.
They could be very profitable if no one prospected them over the past few decades.
The blue ellipses are considered hidden
pay streaks and it’s a pattern inactive at the
moment (maybe it could be active during floods).
The purple ellispes are recent simple and
complex pay streaks, part of the recent
alluvial pattern.
44. 08/03/2018
Materiale didattico gratuito e condivisibile a seguito di
citazione autore: Matteo Oberto 2017.
44
Central pay streaks
In this type of pay streak the greater quantity of gold should be higher than the lower core zones, due to
the main important floods that created them. The blue ellipses are the core zone of central pay streaks.
45. 08/03/2018 45
Erosion curve
An example: the core is the richest portion of a pay streak, in this case the blue ellipse. You could find great quantities of
heavy minerals, like magnetite, garnet and tin.
46. 08/03/2018 46
During a flood there were a few metres of water against this erosion curve. Imagine the force of that flow! How many
m3 of sediments have been eroded?
47. 1 g - How to work a pay streak;
08/03/2018 47
Once the prospectors have exploited a paystreak, he must restore the place in the best way possible.
48. Spotted prospecting
08/03/2018 48
A B C
Field activities order:
- A pay streak has been found by satellite pictures
or by field activity (A);
- The area should be panned by the prospector in
the best places (the volume should be the same for
every sample (B);
- In this phase the prospector could spot the richest
portion of the pay streak, it starts the cultivation phase (C).
This order is notable for exploiting the pay streak in
the right way and the easier way possible.
Blue dots: good gold content by panning;
Yellow dots: low gold quantity;
Blue ellipse: core of the pay streak.
49. 08/03/2018 49
The spot prospecting is a speditive way to prospect
an area, based mainly on panning. In this way
the prospector understands the best places to dig.
50. The circular excavation
08/03/2018 50
A
After a very good prospecting spot, the prospector could increase
the dimension of the test in a circular way.
This type of excavation is used mainly for getting more precise data
from a promising exploitation.
51. Example of circular excavation: central aperture and circular enlargement
08/03/2018 51
Blue ellipse: approximate limit of the excavation,
over that there is still the intact alluvial deposit.
Green ellipse: approximate limit of the tailing from
the sieving phase. The reader should note that there
isn’t any imbrication structuresor auriferous sand
and gravel component. The main structure is chaotic.
The excavation proceeds from a central fulcrum, ubicated where the prospector had the best dot sample, to the external
margin, materializing an ellipse like shape.
52. 08/03/2018 52
A practical example:
It’s evident that the prospectors started from the centre and
they proceded to the external margins in all directions,
drawing a circle – ellipse.
Only the most shallow deposits have been exploited by the
prospectors (30 – 40 cm from the surface).
The refuse should be leveled as restoration and not crowded
at the centre.
53. The hole theory
08/03/2018 53
The lighter ellipses show several moments of the exploitation of the same
alluvial deposit by different prospectors. All of them had a unique plan for
the right exploitation, so they only made holes around the best places.
After months of this activity, the prospector would see a situation similar to
the picture: a very big and messy system of excavations. It is possible that
there is still some good portion that has been buried.
A huge hole doesn’t mean that they found a lot of gold!
Initial
situation
Final
situation
54. An example of rectangular excavation
08/03/2018 54
A
A – spot samplings (a) by panning or other system designs the
core portion of the pay streak;
B - Conservative physiognomy of the excavation. All the core is
included in the excavation limits;
C- Towers of cobbles mark the limit of the rectangular excavation.
a
a
a
a
a
a
C
C
C
C
C
C
55. 08/03/2018 55
This method tends to be conservative, in fact the whole core must be included
in the rectangular limits. Obviously some border portions will contain less gold
but the prospector will be sure that he has exploited all of the core first.
A
a
a
a
a
a
a
C
C
C
C
C
C
56. 08/03/2018 56
Example of a rectangular exploitation
The darker green spots show the best direction for the correct
exploitation, usually determinated by panning.
Linear exploitation is a method, in which the prospector can collect
the best gold from less material. Basically, he or she works out the material
among the green dots.
This is a non-conservative way to exploit due to the material that won’t be
worked by the prospector in the first time. It could be useful when there is
less time to work, or the locality is far.
Orange dots: limits of the rectangular exploitation;
White dots: preliminary dots exploitation and the gold content (shades of green);
Green dots:
- Dark green – Greater gold quantity;
- Green – Medium gold quantity;
- Lighter green – Less gold quantity.
57. 08/03/2018 57
c
c
The greater rectangular side is the most comfortable one
for imposing a limit at the exploitation.
The yellow arrow shows the progression direction of the
exploitation.
During the restoration phase, the prospectors put bigger
cobbles one close to the other and above them a cover
made of smaller clasts, like gravel (waste of the washed
material).
After this adjustment, the spot will be levelled.
An example of rectangular exploitation
Bigger cobbles
Wasted washed gravel
58. 08/03/2018 58
The first part of the exploitation is to extract the cobble cover and
collect the auriferous gravel ubicated among the bigger cobbles.
It is good to wash out the cobbles and all the gravel
in place, and just after bring that material to the sluicing phase.
Sometimes gold could stay attached to rocks!
Then the prospector will put the bigger cobbles behind himself and above
that level, the washed material (made of washed gravel).
The extraction phase
59. 08/03/2018 59
Bed of the exploitation
Main direction of the exploitation Correct way:
Uncorrect way:
Bed of the exploitation
It makes no sense to pile boulders and cobbles in the frontal part of the exploitation or along the borders.
Yes
Profile view:
How to collect auriferous material and restore the site
60. 08/03/2018 60
View from above:
Correct Incorrect
Portion to work
Tailings
Excavation front
During the restoration phase, the prospector should also level the wasted material and not
accumulate a tower.
Green spots: limits of the excavation;
Black spots: boulders or big cobbles.
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The sieving phase is one of the initial processes which is important for reducing the volume of the
processed material. It’s important to be aware of the gold that we will expect due to
our efforts to not waste it. In fact, the net dimension of the sieve retrains a percentage of material (tailings) that
could still contain a lot of gold if it’s present.
The sieving phase
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Generally, a wet sieving is more convenient in terms of
recovery, in fact all auriferous particles could be washed away
during an energetic wet sieving phase.
Instead, the dry sieving is preferred during a dry climate or prolonged
dry seasons, when water is less than normal and the auriferous
material is very dry. In that case the grade of suddivision of the
material could be greater and more convenient.
Usually, finer gold particles tend to stay attached at cobbles or gravel;
the wet sieving helps to collect this percentage.
Dry sieving
Wet sieving
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Sluicing
The sluice is an helpful tool for the prospector, in fact it helps during
the concentration phase or the processing one.
The main goal is to notably reduce the volume of the output
auriferous material and by the sluicing, it is possible.
It works as a concentration tool, where several traps help the
heavier material to be caught. After many hours, the sluice cleaning
can give good results.
We will discuss these tools in greater depth in the next guide.
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The panning
Panning is preferred during the initial steps, when the prospector has to prospect the paydirt, in order to find
a good spot. It’s also used for the final washing phase, when the last portion of material, collected by a sluice, for example,
has to be worked due to extract all gold particles.
Every pan has its own limits and finalities. It is useful to know these aspects, and use the right tool in the correct
situation.
65. Example of wasted sand (sluicing and panning tailings)
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The blue ellipses show localized sluicing and panning tailings, the products of the processing phase.
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A SUMMARY:
The three golden rules:
1- Gold doesn’t become greater with depth;
2- If I’m digging well, I’m already restoring the site;
3- It’s not correct leaving the site with holes, trenches or any kind of rubbish; Clean your path!.
Always remember that your pits could be mortal traps for animals, people or children.
Plan and dig responsibly!
67. 1 h – Prospecting the river banks;
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What are the main components that I should look for?
Each flood is composed by an erosion phase and a deposition phase. The first one may make
an erosion semi-ellipse profile seen in the picture below. The next phase will fill the concave
shape with coarser sediments at the bottom and lighter sediments at the top.
Gold will be concentrated at the bottom of the semi-ellipse.
Orthogonal view with respect to the main
water direction.
Semi-ellipse shape
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The cross concave stratification will be made by several flood episodes that can work together in order to
build the below situation.
This view is available if you can observe an orthogonal cut
with respect to the main water direction in that moment.
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Every flood episode may free new gold from old deposits and so it will be concentrated during the
deposition phase in this way and spatial direction.
Gold will be deposited along the most depressed paths!
Obviously there isn’t just gold but also other heavy minerals, like
magnetite, garnet, tin, etc.
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As the reader can observe, in this picture there is the outcrop of a clay bedrock and locally it has been
eroded. Along the most depressed area good quality gold can be found.
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General conclusions from this guide:
- It’s important to know that nature is more complicated than this guide could highlight, in fact
many old floods can’t be investigated easly and so the easiest way to prospect is to test and panning
different locations.
- This guide has underlined the importance that the gold seekers should fall in love with nature,
and the best gold he can have is the fresh air and the beauty of passing all day in the nature.
It’s also a job for the prospectors to keep the localities clean where they prospect.
- It’s obviously important to be aware of legislation, each state or region
has its own rules and the prospector has to follow them.
The legal aspects are a priority!
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See you in the next guide!
The author hopes that this guide can be helpful to other prospectors around the world, who do not
have much geological background but would like to learn more about gold prospecting.
In the next guide, the main topic will be: “Techniques and gold prospecting”
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Author’s notes:
This guide was written in November 2017.
It was written by the author specifically for prospectors or amateurs, who want
to look for gold and who would like to improve their gold recovery. The guide will be
maintained for up to date information which is easy to access.
See you in the next guide!
Matteo
Oberto
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Contact details:
If you want to contact me for cultural and scientific events such as radio calls, skype interviews etc, you can find me at:
Oberto.matteo@libero.it
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you can find me on Facebook, look for: Matteo Oberto.
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