The document discusses skarn deposits, which are metallic deposits associated with skarn rocks formed by the chemical alteration of carbonate rocks like dolostone and limestone. It defines skarn and its classifications, discusses associated mineral deposits, and highlights potential occurrences in Nigeria. Specifically, it notes that the Younger Granites Complex and marble-bearing schist belts may host skarn occurrences in Nigeria rich in iron, copper, gold, and molybdenum deposits. The document also presents a case study of the Antamina copper-zinc skarn deposit in Peru to illustrate deposit geology and mineralization.
Komattite
Named after the Komati River in South Africa.
first described by Morris and Richard (twins) for ultramafic units in the Barberton Greenstone belt of South Africa.
Mostly of komatiite are Archean age
distributed in the Archaean shield areas.
Also a few are Proterozoic and Phanerozoic.
In all ages komatiites are highly magnesium.
Mostly a volcanic rock; occasionally intrusive.
Mafic rocks were identified as extrusive because of their volcanic textures and structures, and they seem to have been accepted as a normal component of Archean volcanic successions, Abitibi in Canada.
The ultramafic rocks were interpreted as intrusive which are founded as sills and dykes, Barberton in South Africa.
Spinifex texture-typical of Komatiites:
Slides related to wall rock alteration.In these slides it is described that how host rock behave when it comes in contact with the hydro thermal fluid coming from deep Earth (Mantle) and their results.
Komattite
Named after the Komati River in South Africa.
first described by Morris and Richard (twins) for ultramafic units in the Barberton Greenstone belt of South Africa.
Mostly of komatiite are Archean age
distributed in the Archaean shield areas.
Also a few are Proterozoic and Phanerozoic.
In all ages komatiites are highly magnesium.
Mostly a volcanic rock; occasionally intrusive.
Mafic rocks were identified as extrusive because of their volcanic textures and structures, and they seem to have been accepted as a normal component of Archean volcanic successions, Abitibi in Canada.
The ultramafic rocks were interpreted as intrusive which are founded as sills and dykes, Barberton in South Africa.
Spinifex texture-typical of Komatiites:
Slides related to wall rock alteration.In these slides it is described that how host rock behave when it comes in contact with the hydro thermal fluid coming from deep Earth (Mantle) and their results.
How can minerals deposits be formed; GEOLOGICAL PROCESSES; Ore Fluids; Ore Forming Processes; Concentrating Processes; Magmatic mineral deposits; Residual mineral deposits ; Placer deposits; Sedimentary mineral deposits; Metamorhogenic mineral deposits; Hydrothermal mineral deposits ; Magmatic Deposits
Cumulate deposits: fractional crystallization processes can concentrate metals (Cr, Fe, PGE, Pt, Ni, Ti, Diamond ))
Pegmatites : late staged crystallization forms pegmatites and many residual elements are concentrated (Li, Ce, Be, Sn, U, Rare Earths (REE), Feldspar, Mica, Gems).
magmatic deposits; Mode of Formation of Magmatic Ores Deposits; Mode of Formation of Orthomagmatic Ores ; Fractional Crystallization (or Crystal fractionation ); Magmatic (or Liquid ) Immiscibility; Simple crystallization without concentration (Dissemination); Segregation of early formed crystals; (Layer Types); Injection of material concentrated elsewhere by differentiation Residual liquid segregation; Residual liquid injection; Immiscible liquid segregation; Immiscible-liquid-injection; Early magmatic deposit; Late magmatic deposit; Types of Magmatic Ore Deposits:Chromite; Fe-Ti (± V) oxides; Ni – Cu – Fe (± Pt) sulfides; Platinum Group Elements (PGEs); REE, and Zr in Carbonatites; Diamond in kimberlites.
Texture of Ore Minerals; Importance of Studying Textures; Individual Grains Properties; Filling of voids; Texture Types; Genetically differentiated between Texture types; Secondary textures from replacement; Hypogene Texture; Supergene Texture; Primary texture formed from Melts; Primary texture of open-space deposition; Secondary textures from cooling; Secondary textures from deformation; TEXTURES OF ECONOMIC ORE DEPOSITS; Textures of Magmatic ores; Cumulus textures; Intergranular or intercumulus textures; Exsolution textures; Textures of hydrothermal ore deposits and skarns; Replacement textures; Open space filling textures; Textures characteristic of surfacial or near surface environments and processes; Criteria for identifying replacement textures; Vein and Veining have different Nature Features
THE PRESENCE AND VARIETY OF A PARTICULAR PLANTS
SPECIES IN THE AREA OF MINERALISATION HAVE BEEN RECOGNISED AS A GUIDE TO LOCATING ORE, METHOD,UNIVERSAL INDICATORS , UNIVERSAL INDICATOR ,LOCAL INDICATOR
A presentation on Hydrothermal wall rock alteration with case studies on geophysical applications.
References : https://drive.google.com/drive/folders/16VSZMPMASMNVB47JdBUa_7udBk1qvK2U?usp=sharing
Metallogenic Epoch and Province
Metallogenetic Epochs
Metallogenetic epochs, as defined above, are specific periods characterised by formation of large number of mineral deposits. It does not mean that all the mineral deposits formed during a definite metallogenetic epochs. In India the chief metallogenetic epochs were:
1. Precambrian
2. Late Palaeozoic
3. Late Mesozoic to Early Tertiary
How can minerals deposits be formed; GEOLOGICAL PROCESSES; Ore Fluids; Ore Forming Processes; Concentrating Processes; Magmatic mineral deposits; Residual mineral deposits ; Placer deposits; Sedimentary mineral deposits; Metamorhogenic mineral deposits; Hydrothermal mineral deposits ; Magmatic Deposits
Cumulate deposits: fractional crystallization processes can concentrate metals (Cr, Fe, PGE, Pt, Ni, Ti, Diamond ))
Pegmatites : late staged crystallization forms pegmatites and many residual elements are concentrated (Li, Ce, Be, Sn, U, Rare Earths (REE), Feldspar, Mica, Gems).
magmatic deposits; Mode of Formation of Magmatic Ores Deposits; Mode of Formation of Orthomagmatic Ores ; Fractional Crystallization (or Crystal fractionation ); Magmatic (or Liquid ) Immiscibility; Simple crystallization without concentration (Dissemination); Segregation of early formed crystals; (Layer Types); Injection of material concentrated elsewhere by differentiation Residual liquid segregation; Residual liquid injection; Immiscible liquid segregation; Immiscible-liquid-injection; Early magmatic deposit; Late magmatic deposit; Types of Magmatic Ore Deposits:Chromite; Fe-Ti (± V) oxides; Ni – Cu – Fe (± Pt) sulfides; Platinum Group Elements (PGEs); REE, and Zr in Carbonatites; Diamond in kimberlites.
Texture of Ore Minerals; Importance of Studying Textures; Individual Grains Properties; Filling of voids; Texture Types; Genetically differentiated between Texture types; Secondary textures from replacement; Hypogene Texture; Supergene Texture; Primary texture formed from Melts; Primary texture of open-space deposition; Secondary textures from cooling; Secondary textures from deformation; TEXTURES OF ECONOMIC ORE DEPOSITS; Textures of Magmatic ores; Cumulus textures; Intergranular or intercumulus textures; Exsolution textures; Textures of hydrothermal ore deposits and skarns; Replacement textures; Open space filling textures; Textures characteristic of surfacial or near surface environments and processes; Criteria for identifying replacement textures; Vein and Veining have different Nature Features
THE PRESENCE AND VARIETY OF A PARTICULAR PLANTS
SPECIES IN THE AREA OF MINERALISATION HAVE BEEN RECOGNISED AS A GUIDE TO LOCATING ORE, METHOD,UNIVERSAL INDICATORS , UNIVERSAL INDICATOR ,LOCAL INDICATOR
A presentation on Hydrothermal wall rock alteration with case studies on geophysical applications.
References : https://drive.google.com/drive/folders/16VSZMPMASMNVB47JdBUa_7udBk1qvK2U?usp=sharing
Metallogenic Epoch and Province
Metallogenetic Epochs
Metallogenetic epochs, as defined above, are specific periods characterised by formation of large number of mineral deposits. It does not mean that all the mineral deposits formed during a definite metallogenetic epochs. In India the chief metallogenetic epochs were:
1. Precambrian
2. Late Palaeozoic
3. Late Mesozoic to Early Tertiary
Seismic Reflection Surveys in Search for Iron Oxide Copper-Gold (IOCG) Depositsiosrjce
Seismic reflection method can delineate very complex geological structures hence it might be very
effective for detecting the presence of Iron Oxide Copper-Gold (IOCG) deposits. Despite this superior
attributes, there exist a real problem for exploration beyond the immediate vicinity of a known deposit. All
previous studies have focused upon high resolution detection of mineralization and the hosting structures at
mine scale. No argument for “regional” exploration have been proposed probably because a cost benefit
analysis has never be conducted at such scale to proceed with such exploration venture. In this study, we
analyze the feasibility of such regional exploration by modelling a Vulcan IOCGU deposit scenario were a 2D
seismic survey with relatively sparse source-receiver geometry was used to detect the presence of a possible
intrusive package within 2km depth range. The modelling results demonstrates that seismic reflection method
using 10m geophones and 20m shot spacing can be used to image deposit within the depth of 2km. The
presence of reflections was visibly observed especially at the edges of intrusive packages hence it is suggested
that application of seismic reflection methods perhaps will remains the best alternative and most viable method
for exploring deep seated IOCG
Geochemistry and Genesis of Kammatturu Iron Ores of Devagiri Formation, Sandu...IJMER
The Greenstone belts of Karnataka are enriched in BIFs in Dharwar craton, where Iron
formations are confined to the basin shelf, clearly separated from the deeper-water iron formation that
accumulated at the basin margin and flanking the marine basin. Geochemical data procured in terms of
major, trace and REE are plotted in various diagrams to interpret the genesis of BIFs. Al2O3, Fe2O3 (T),
TiO2, CaO, and SiO2 abundances and ratios show a wide variation. Ni, Co, Zr, Sc, V, Rb, Sr, U, Th,
ΣREE, La, Ce and Eu anomalies and their binary relationships indicate that wherever the terrigenous
component has increased, the concentration of elements of felsic such as Zr and Hf has gone up. Elevated
concentrations of Ni, Co and Sc are contributed by chlorite and other components characteristic of basic
volcanic debris. The data suggest that these formations were generated by chemical and clastic
sedimentary processes on a shallow shelf. During transgression, chemical precipitation took place at the
sediment-water interface, whereas at the time of regression. Iron ore formed with sedimentary structures
and textures in Kammatturu area, in a setting where the water column was oxygenated.
PowerPoint Presentation prepared for the PDAC 202mining convention as an explainer tool for Major Mining companies, with a view to joint venture the Pecors Nickel, Copper, Platinum, Palladium, Gold project at Pecors lake, Ontario, Canada
Komattite
Named after the Komati River in South Africa.
first described by Morris and Richard (twins) for ultramafic units in the Barberton Greenstone belt of South Africa.
Mostly of komatiite are Archean age
distributed in the Archaean shield areas.
Also a few are Proterozoic and Phanerozoic.
In all ages komatiites are highly magnesium.
Mostly a volcanic rock; occasionally intrusive.
Mafic rocks were identified as extrusive because of their volcanic textures and structures, and they seem to have been accepted as a normal component of Archean volcanic successions, Abitibi in Canada.
The ultramafic rocks were interpreted as intrusive which are founded as sills and dykes, Barberton in South Africa.
Spinifex texture-typical of Komatiites:
The name Spinifex refer to a spiky grass in Australian.
Distribution and Mobility of Heavy Metal Materials in Settling Ponds Post Lat...IJERA Editor
The formation of waste matter sedimentation in settling ponds, along with accumulation of heavy metals, such as Nickel (Ni), Chrome (Cr3+ and Cr6+), manganese (Mn) and Cobalt (Co) and elements or compounds in laterite soil. These heavy metals will concentrate in different environmental geochemistry, which are laterite sediment layers pre- and post-mining. The purposes of this study are to identify changes of heavy metal distribution in settling ponds and analyze heavy metal mobility in settling ponds. The research methods were qualitative and quantitative methods. Laboratory research used AAS (Atomic Absorption Spectrophotometer) which was studied, analyzed, and synthesized comprehensively. Data processing technique used SPSS v.21 software and Principal Component Analysis (PCA) method. The result showed that distribution of heavy metals Fe and Cr relatively strengthened constantly. The graphs of Fe and Cr were interpreted as similar mobility and mechanism of transportation os elements which can form chemical compounds. Meanwhile, metals Ni and Co had similar graph which was relatively flat constantly. This was interpreted as similar mobility of heavy metals in settling ponds. The mobility of heavy metals Fe and Cr were mostly concentrated to form ferrochrome compound in the sediment of settling ponds compared with Ni with its low mobility and Co with its very low mobility.
BASALT RESOURCES OF LOPBURI PROVINCE, THAILAND: A POTENTIAL SOURCE FOR BASALT...Seangleng Hoeun
Apart from a good host of ruby and sapphire, basalts and basaltic rocks can be used for other purposes, especially as producing construction material and making basalt fibers. Basalt has been widely used as concrete aggregate, pavement aggregate, railroad ballast and dimension stone. Not only these conventional applications, but also high quality fiber can be drawn from molten basalt with outstanding mechanical and chemical advantages comparing to hazardous asbestos fiber. Having higher strength and more stable in alkalinity than E-glass, basalt fiber is cheaper than the high-strength-low-density carbon fiber. With high thermal and abrasion resistance, basalt fiber could replace asbestos in various usages. Although all basalt can be used to make fiber, its quality depends largely on mineralogy, chemical composition and recrystallization behaviors of basaltic melts.
The aim of this research is to evaluate the suitability of basalt resources in Lopburi Province, Thailand for making basalt fiber. Integrated results of petrological analysis, mineralogical and geochemical investigation as well as basalt melts’ characterization are presented in this research to delineate the suitability of the basalt resources for producing fiber. The complex geological evolution in central Thailand introduced very high variations of basalt composition and genesis. In some occurrences, basalt found highly altered due to the flow of basaltic lava over pre-existing rhyolitic layer, making it more sensitive to weathering. Meanwhile, some basalt deposits might be metamorphosed through which it makes changes in mineral and chemical compositions. However, fresh basalt to andesitic basalt was also found in some areas, which might be suitable for making fiber due to its unchanged mineralogical and chemical composition. Covering approximately one fourth of the total area of the province, Lopburi basaltic rocks are situated fairly close to a number of industrial zones, where are very advantageous for basalt fiber production.
At the 2010 Prospector's and Developers Association of Canada (PDAC) Conference, David Lentz and Anthony Mariano gave a presentation on ranking and evaluating light to heavy rare earth deposits worldwide. This is that presentation.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
1. THE FEDERAL UNIVERSITY OF TECHNOLOGY,
AKURE, ONDO STATE, NIGERIA.
SEMINAR PRESENTATION ON
SKARN DEPOSITS
BY:
OBI, VICTOR CHIZOBA
IN PARTIAL FUFILMENT OF THE
REQUIREMENT FOR THE AWARD OF THE
DEGREE OF BACHELOR OF TECHNOLOGY,
APPLIED GEOLOGY
OCTOBER, 2017.
1
2. Presentation Outline
2
• Aim
• Objectives
INTRODUCTION
• Definition and Composition
• Formation
• Classification
• Profile and speculations in Nigeria
CASE STUDY
• The Geology of Antamina Cu-Zn Skarn deposit, Peru
• Industrial importance of Skarn deposits
CONCLUSION AND RECOMMENDATION
3. 3
AIM
•To Understand and discuss the basic theories and
principles of skarn deposits.
OBJECTIVES
• To define skarn and its classifications;
• To discuss the mineral deposits associated with skarns;
• To highlight possible occurences in Nigeria.
4. INTRODUCTION: DEFINITION AND COMPOSITION
4
A METASOMATIC ROCK
SKARN IS
FORMED BY CHEMICAL ALTERATION OF
CARBONATE (DOLOSTONE AND LIMESTONE)SKARN IS
ARE METALLIC DEPOSITS ASSOCIATED WITH
SKARN ROCK FORMING MINERALS.
SKARN
DEPOSITS
7. FORMATION OF SKARN
7
Isochemical metamorphism:
Metasomatic transfer of components between
adjacent lithologies on a small scale (argillite and
limestone, banded iron formation and limestone)
forming reaction skarns.
Infiltration metasomatism:
Hyrdrothermal fluid interaction
(magmatic/metamorphic origin) with calcareous
rocks forming replacement or infiltration skarns.
(Ray et al. (1997) and Meinert (1992)
8. 8
FORMATION OF SKARN
ISOCHEMICAL METAMORPHISM
INTRUSION OF MAGMA (900⁰C – 700⁰C
METAMORPHIC RECRYSTALLIZATION,
FLUID CIRCULATION AND LOCAL
BIMETASOMATISM FORMING
REACTION SKARNS AND SKARNOIDS
FROM IMPURE LITHOLOGIES
Figure 2: Isochemical Metamorphism, Modified after Meinert (1992, 1995).
9. 9
SKARN CLASSIFICATION
Soloviev et al. (2013) and Ray et al. (1997)
BASED ON ALTERATION ASSEMBLAGES
•PROGRADE CALCIC SKARN
•PROGRADE MAGNESIUM SKARN
BASED ON PROTOLITH
•ENDOSKARN
•EXOSKARN
12. PROFILE OF SKARN DEPOSITS
12
Main Metal
(By-products)
Fe (Cu, Ag, Au)
Tectonic setting Calcic Fe skarns: Oceanic Island arc
Magnesium Fe Skarns: Continental margin
Host/Associated Rock Types Calcic Fe Skarns: Dykes of Gabbro to
syenite intruding limestone
Magnesium Fe Skarns: Granodiorite to
Granite intruding dolomite and dolomitic
sedimentary rocks
Ore Mineralogy Principal Ore: Magnetite. Subordinate Ore:
Chalcopyrite, bornite, pyrite, etc.
Grade and Tonage Grades are typically 40 to 60%
TABLE 1: Characteristics of Fe Skarn
13. 13
CU SKARN DEPOSIT
Main Metal
(By-Products)
Cu (Au, Ag, Mo, W)
Tectonic Setting Andean-type plutons intrude older
continental-margin carbonate sequences
Hosted / Associated Rock
Types
Dykes and Breccia types of quartz diorite,
granodiorite, etc.
Ore Mineralogy (Moderate to high sulphide content) Pyrite,
Chalcopyrite, magnetite, etc.
Grade and Tonage Average 1 to 2 % Cu
Compiled from: Nadoll et al., 2015; Ray et al., 1997 and soloviev, 2015)
TABLE 2: Characteristics of Cu Skarn
15. 15
Tin (Cassiterite) Deposits in The Younger Granites Complex of
Nigeria.
Schist Belts of Nigeria.
OCCURRENCES (OR SPECULATIONS) OF SKARN
IN NIGERIA
16. 16
Marble occurrences (Schist Belts) in the Precambrian
Basement Complex of Nigeria.
lifeinplanetlight.wordpress.com
Figure 4: Model for Marble formation from Contact Metamorphism
17. 17
CASE STUDY
THE GEOLOGY OF THE ANTAMINA COPPER-ZINC SKARN
DEPOSIT, PERU.
It is located in the eastern part of the Western Cordillera of
north Peru at 9° 32’ south and 77° 03’ west, at an altitude
between 4,200 and 4,800 meters.
Antamina is hosted by Mesozoic carbonates that are within a
fold and thrust belt in the eastern part of the Western
Cordillera.
Antamina is hosted by Cretaceous sedimentary rocks that
comprise carbonates overlying a sandstone-shale-coal sequence.
19. 19
CASE STUDY
Figure 6: Cross Section 20, 200N showing skarn zonation (After, Stewart D. Redwood)
20. 20
MINERALIZATION
The skarn is dominantly garnet.
The metals are also zoned, with copper in the brown garnet and
copper-zinc in the green garnet.
The core intrusion actually comprises a series of quartz monzonite
porphyry intrusions that can be divided into early, middle, and late
phases.
21. ECONOMIC OR INDUSTRIAL APPLICATION
Tin has long been used in alloys with lead
as solder.
Tin in combination with other elements
forms a wide variety of useful alloys
Figure 7 :A coil of lead-free solder wire
Figure 8: A plate of Tin in combination with other elements
forms a wide variety of useful alloys Molybdenum Copper
Alloy 21
22. 22
ECONOMIC OR INDUSTRIAL APPLICATIONS
(CONTD)
Tungsten is mainly used in the production of hard materials based on tungsten carbide
Lead has been used for bullets since their invention in the middle Ages
Lead is still used in statues and sculptures (Fig. 10), including for armatures
Figure 9: Tungsten carbide ring (jewelry) Figure 10: A 17th –century gold-plated lead sculpture
23. ECONOMIC OR INDUSTRIAL APPLICATIONS
(CONTD)
23
Gold is usually alloyed with base metals for use in jewelry because of the softness of pure (24k)
Copper is used to make copper fittings
Figure 12: Moche gold necklaceFigure 11: Copper fittings
24. 24
ECONOMIC OR INDUSTRIAL APPLICATIONS
(CONTD)
Copper wire is used in power generation, power transmission, power distribution,
telecommunications, electronics circuitry, and countless types of electrical equipment
ARCHITECTURAL PURPOSES
Figure 14: Copper roof on the Minneapolis city hall, with patinaFigure 13: Copper electrical busbars distributing
coated power to a large building
25. Skarn, as a metasomatic rock is a product of hydrothermal alteration of
calcium- and magnesium-rich carbonate rocks. Its formation is associated
with the concentrations of metallic deposits (skarn deposits).
The Younger Granites Complex and marble-bearing Schist Belts are the
possible locations of skarn occurrences in Nigeria. The marble-bearing
schist belts in the country are likely to be host to exoskarns rich in Fe, Cu,
Au and Mo skarn deposits.
CONCLUSION
25
26. RECOMMENDATION
I employ that more researches be executed as far as exploring and exploiting
skarn deposits is concerned in Nigeria especially in the Younger Granites of
Nigeria which is in a non-rifted extensional environment, is likely to have
been associated with the hydrothermal system in a skarn environment
Secondly, marbles, in the Schist Belts of Nigeria, formed by contact
metamorphism, have been discovered to be sharing similar protoliths and
agents of metamorphism with skarn; hence, the possibility of skarn
occurrences in the marble-bearing schist belts in the country is probable
26
27. REFERENCE
26
Meinert L. D., 1992, Skarn and Skarn Deposits: Geoscience Canada 19 (4), 145-162.
Ray, G.E, Dawson, G.L. and Simpson, R., 1988, Geology, geochemistry and metallogenic zoning
in the Hedley Gold-Skarn camp, 1987, Paper 1988-1, p. 59-80.
Soloviev, S. G., 2015, Geology, mineralization, and fluid inclusion characteristics of the
Kumbel oxidized W–Cu–Mo skarn and Au–W stockwork deposit in Kyrgyzstan, Tien Shan:
Mineralium Deposita 25 (2), 187-220.
Nadoll, P., Mauk J. L., Leveile R. A. and Koenig A. E., 2015, Geochemistry of magnetite from
porphyry Cu and skarn deposits in the Southwestern United States: Mineralium Deposita 50 (4), 493-
515.
Soloviev, S. G., Kryazhev, S. G. and Dvurechenskaya, S. S., 2013, Geology, mineralization, stable
isotope geochemistry, and fluid inclusion characteristics of the Novogodnee–Monto oxidized Au–
(Cu) skarn and porphyry deposit, Polar Ural, Russia: Mineralium Deposita 48 (5), 603-627.
http://www.danieleheon.com/fieldwork-photos-yukon--bc.html
Stewart D. Redwood and Shanks: International Geology Review, v. 12, p. 761-858.
If the fluids are undersaturated in Si, too high in CO2, or too low in temperature, the wollastonite-rich zone is not developed.
Essential minerals: garnet, clinopyroxene, epidote, calcic amphibole and wollastonite.
Endoskarn signature, presence of greisens and its associated high-fluorine activities. The earlier skarn deposits in the igneous rock environment may have been destroyed by the greisen-stage alteration
Endoskarn signature, presence of greisens and its associated high-fluorine activities. The earlier skarn deposits in the igneous rock environment may have been destroyed by the greisen-stage alteration
The most abundant metal determines the skarn deposit type and this is also governed by the source of the hydrothermal fluid, tectonic setting of emplacement, structures on the protolith and the composition of the protolith.
Endoskarn is much likely to occur in the igneous environment (Younger Granites Complex) with the associated greisens and high fluorine activities (suitable conditions for Sn Skarn Deposits).
