Plate tectonics, like crustal evolution, provides a basis for understanding the distribution and origin of mineral and energy deposits. Different types of ores are characterized by distinct geological environment and tectonic settings.
Minerals are formed by changes in chemical energy in systems which contain one fluid or vapor phase. In nature, minerals are formed by crystallisation or precipitation from concentrated solutions. These solutions are called as ore-bearing fluids. Ore-bearing fluids are characterised by high concentration of certain metallic or other elements.
Fluids are the most effective agents for the transport of material in the mantle and the Earth's crust.
Information about these fluids is an invaluable aid in mineral exploration.
Conventional academic methods of analysing fluid inclusions are too slow and tedious to be of practical application in typical mineral exploration activities.
However, the academic data from numerous studies does show that CO2 is an exceptionally important indicator when exploring for most types of gold deposit.
Because the baro-acoustic decrepitation method is a rapid and reliable method to measure CO2 contents in fluids, it can be used to study a spatial array of data and it is an invaluable and practical exploration method.
Measurements of temperatures of fluid inclusions does not usually help in mineral exploration as hydrothermal minerals deposit over a wide temperature range and there is no specific temperature which is indicative of mineralisation. However, if temperatures are available on a large spatial array of samples, then temperature trends may be a useful exploration method to find the hottest part of the system, which is presumably the location of the best economic mineralisation. Baro-acoustic decrepitation is the most practical method to determine temperatures of the large numbers of samples required.
Salinities of fluid inclusions are of limited use in exploration and are difficult to measure. However, they can be used to recognise intrusion related hydrothermal systems.
Minerals are formed by changes in chemical energy in systems which contain one fluid or vapor phase. In nature, minerals are formed by crystallisation or precipitation from concentrated solutions. These solutions are called as ore-bearing fluids. Ore-bearing fluids are characterised by high concentration of certain metallic or other elements.
Fluids are the most effective agents for the transport of material in the mantle and the Earth's crust.
Information about these fluids is an invaluable aid in mineral exploration.
Conventional academic methods of analysing fluid inclusions are too slow and tedious to be of practical application in typical mineral exploration activities.
However, the academic data from numerous studies does show that CO2 is an exceptionally important indicator when exploring for most types of gold deposit.
Because the baro-acoustic decrepitation method is a rapid and reliable method to measure CO2 contents in fluids, it can be used to study a spatial array of data and it is an invaluable and practical exploration method.
Measurements of temperatures of fluid inclusions does not usually help in mineral exploration as hydrothermal minerals deposit over a wide temperature range and there is no specific temperature which is indicative of mineralisation. However, if temperatures are available on a large spatial array of samples, then temperature trends may be a useful exploration method to find the hottest part of the system, which is presumably the location of the best economic mineralisation. Baro-acoustic decrepitation is the most practical method to determine temperatures of the large numbers of samples required.
Salinities of fluid inclusions are of limited use in exploration and are difficult to measure. However, they can be used to recognise intrusion related hydrothermal systems.
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.
This is my presentation on the tectonic control of sediments.
It includes the effects of tectonics either direct or indirect on sediments and sedimentation.
Sedimentation along various plate boundaries.
Few examples as evidence from Pakistan (the Siwalik Group) and Argentina (Fiambala Basin)
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
CLASSIFICATION OF ORE DEPOSITS
The Mixture of ore minerals are gangue minerals form an Ore deposit. The ore
deposits are generally found enclosed within the country rocks. The ore deposits
are formed in many different ways. Depending upon the process that may
operate to produce them, the ore deposits may be classified as follow:
Magmatic ore deposits.
Sublimation ore deposits.
Pegmatitic ore deposits.
Contact metasomatic ore deposits.
Hydrothermal ore deposits
Cavity filling deposits.
Replacement deposits.
Sedimentation ore deposits.
Evaporation ore deposits.
Residual and mechanical concentration deposits
Metamorphic ore deposits.
MAGMATIC ORE DEPOSITS:
The magmatic ore deposits are the magmatic products which crystallize from
magmas. The magmatic ore deposits are classified as follows:
o Early magmatic deposits
o Late magmatic deposits
Early magmatic deposits:
Early magmatic deposits are formed during the
early stage of the magmatic period. In this case the
ore minerals crystallize earlier than the rock
silicates. The Minerals of Nickel, Chromium, and
Platinum are usually found as early magmatic
deposits. The early magmatic deposits can be sub
divided into two groups:
o Dissemination deposits
o Segregation deposits
Dissemination deposits:
When magma crystallizes
conditions, a granular igneous rock is formed. In
such a rock early formed crystals of
may occur in dissemination.
Segregation deposits:
Magmatic segregation deposits are
formed as a result of gravitative
crystallization differentiation. In
case, the ore mineral which crystallize
early, get ocean-trated on a particular
part of igneous part. The ore deposits
thus formed are known as “Segregation
deposits”.
rly under seated
ore minerals
such
Late Magmatic Deposits:
The ore deposits which are formed to
called late magmatic deposits. The late magmatic deposits contain those ore
minerals which have crystallized at rather low temperature from the residual
magma. The magma which is left after crystallization of early for
is called residual magma. This magma frequently contains many ore minerals. The
late magmatic deposits include most of the magmatic deposits of iron and
titanium ores, these deposits are almost always associated with mafic igneous
rocks.
SUBLIMATION DEPOSITS:
Sublimation is a very minor process of formation of ore deposits. Sublimation
deposits contain only those minerals which have been volatilized by hear and
subsequently redeposit in the same form at low temperature and pressure. The
sublimation deposits are found associated with Volcanoes and Fumaroles. Sulfur
of this origin has been mined in Japan, Italy, and Mexico.
Deep sea mining is a new frontier for mining engineers. Sea floor holds the potential mineral that are vital for development which is not even explored, the advancement of technology in the time will enable to access reliable infrastructure and methods to extract sea floor without compromising the sustainability and eco friendly.
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.
This is my presentation on the tectonic control of sediments.
It includes the effects of tectonics either direct or indirect on sediments and sedimentation.
Sedimentation along various plate boundaries.
Few examples as evidence from Pakistan (the Siwalik Group) and Argentina (Fiambala Basin)
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
CLASSIFICATION OF ORE DEPOSITS
The Mixture of ore minerals are gangue minerals form an Ore deposit. The ore
deposits are generally found enclosed within the country rocks. The ore deposits
are formed in many different ways. Depending upon the process that may
operate to produce them, the ore deposits may be classified as follow:
Magmatic ore deposits.
Sublimation ore deposits.
Pegmatitic ore deposits.
Contact metasomatic ore deposits.
Hydrothermal ore deposits
Cavity filling deposits.
Replacement deposits.
Sedimentation ore deposits.
Evaporation ore deposits.
Residual and mechanical concentration deposits
Metamorphic ore deposits.
MAGMATIC ORE DEPOSITS:
The magmatic ore deposits are the magmatic products which crystallize from
magmas. The magmatic ore deposits are classified as follows:
o Early magmatic deposits
o Late magmatic deposits
Early magmatic deposits:
Early magmatic deposits are formed during the
early stage of the magmatic period. In this case the
ore minerals crystallize earlier than the rock
silicates. The Minerals of Nickel, Chromium, and
Platinum are usually found as early magmatic
deposits. The early magmatic deposits can be sub
divided into two groups:
o Dissemination deposits
o Segregation deposits
Dissemination deposits:
When magma crystallizes
conditions, a granular igneous rock is formed. In
such a rock early formed crystals of
may occur in dissemination.
Segregation deposits:
Magmatic segregation deposits are
formed as a result of gravitative
crystallization differentiation. In
case, the ore mineral which crystallize
early, get ocean-trated on a particular
part of igneous part. The ore deposits
thus formed are known as “Segregation
deposits”.
rly under seated
ore minerals
such
Late Magmatic Deposits:
The ore deposits which are formed to
called late magmatic deposits. The late magmatic deposits contain those ore
minerals which have crystallized at rather low temperature from the residual
magma. The magma which is left after crystallization of early for
is called residual magma. This magma frequently contains many ore minerals. The
late magmatic deposits include most of the magmatic deposits of iron and
titanium ores, these deposits are almost always associated with mafic igneous
rocks.
SUBLIMATION DEPOSITS:
Sublimation is a very minor process of formation of ore deposits. Sublimation
deposits contain only those minerals which have been volatilized by hear and
subsequently redeposit in the same form at low temperature and pressure. The
sublimation deposits are found associated with Volcanoes and Fumaroles. Sulfur
of this origin has been mined in Japan, Italy, and Mexico.
Deep sea mining is a new frontier for mining engineers. Sea floor holds the potential mineral that are vital for development which is not even explored, the advancement of technology in the time will enable to access reliable infrastructure and methods to extract sea floor without compromising the sustainability and eco friendly.
In this presentation we discuss cobalt crusts, its classification, Occurrence and Distribution, Formation, Texture, Mineralogy, Scope for future mining and exploration.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
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.
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.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
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.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
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.
1. 1
DEPARTMENT OF APPLIED GEOLOGY
SCHOOL OF ENGINEERING AND TECHNOLOGY
DR. HARISINGH GOUR VISHWAVIDYALAYA (A CENTRAL UNIVERSITY)
PRESENTATION ON: Ore Deposits and Plate Tectonics.
GUIDED BY PRESENTED BY
PROF R.K. TRIVEDI GOURAV RAJAK
Course Co-Ordinator M. TECH 3rd SEM
2. Contents.
1. Plate tectonic and Ore deposits.
• Intracratonic Basins.
• Domes, Rifts and Aulacogens.
• Hotspot Associated Mineralization.
• Continental Rifting.
2. Interior Basins and Intracratonic rifts and Aulacogens
• Cyprus type deposits
3. Ocean Basins and Rises
4. Passive Continental Margins
• Island Arcs
• Continental Margin Arcs
5. Subduction related settings
6. Strike Slip Settings
• I type Granite
• S type Granite
7. Collision Related Settings
2
3. Plate Tectonic and Ore Deposits
• Plates or Lithospheric plates are rigid but thin (100-150 km) plates sliding
over partially molten plastic layer called the Asthenosphere.
• Plates = Oceanic Crust + Continental Crust.
• These plates are made up of plate boundaries and are classified based on
their mutual interface such as
i) constructive type, ii) destructive type, and iii) conservative type.
3
4. • Plate tectonics, like crustal evolution, provides a basis for understanding the
distribution and origin of mineral and energy deposits. The relationship of
plate tectonics and mineral deposits is significant on three counts:
1. Geological processes operating due to energy released at plate
boundaries control the process of mineral deposition.
2. Mineral deposits form in particular tectonic settings which are governed
by plate tectonics.
3. Reconstruction of fragmented continents can provide a useful basis for
exploration of new mineral deposits.
4
5. T
ectonicSettings
According to Mitchell & Reading(1986), six tectonic settings
will be discussed here:-
1. Interior Basins and Intracratonic rifts and Aulacogens
2. Oceanic basins and rises
3. Passive continental margins
4. Subduction – related settings
5. Strike- slip settings
6. Collision- related settings.
5
6. 1. Interior Basins and Intracratonic Rifts & Aulacogen
Continental Interior Basins (Intracratonic Basins)
Intracratonic sedimentary basins occur in the middle of stable continental or
cratonic blocks.
• May contain entirely of continent sediments, deposited in larger lakes eg
Chad Basin of Africa.
• Archaean Basins:- Dominion Reef and Witwatersrand Supergroup of South
Africa were laid down containing important Gold mineralization.
• Proterozoic Basins:- Hurronion Supergroup with Uraniferous
Conglomerates
• Phanerozoic Basins:- Important for their evaporite deposits, such as the
Permian Zechstein evaporates of central Europe.
6
7. Indian Examples:
• There are three large intracratonic basins (Vindhyan, Cuddapah and
Chattisgarh) and several smaller basins (Kaladgi, Bhima, Pakhal,
Penganga, Indravati, Khariar, Sabari and Kolhan).
• Cuddapah :- Uranium resource and Pb–Zn sulphide mineralization.
• Bhima and Kaladgi basin:- Uranium mineralization.
• Penganga basin:- Manganese.
7
9. Domes, Rifts and Aulacogens.
• These are initiated by the doming of continental areas which, due to
stretching, develop three rift valleys that meet at a 120° triple junction.
• Two of the rift valleys may combine to form a divergent plate boundary
leading through graben development to ocean spreading, whilst the third
arm may show only partial development.
• The third arm is called failed arm or Aulacogen.
• Examples:- Kutch rift and Cambay rift.
• Aulacogens are characterized by the presence of fluorite, barite,
carbonatites (with Nb, P, REE, U, Th etc) and Sn-bearing granites.
9
Doming Stretching Rifting Divergence
10. Hotspot associated Mineralisation.
• Plumes may cause melting of the continental crust forming granitic
intrusions, e.g., the Cabo Granite of Brazil
• Tin provinces in Nigeria, Brazil, Saudi Arabia and Sudan are often associated
with sodic granites in ring complexes.
10
Fig 3. Sketch map showing the locations of the Benue
Trough, the Amazon Rift Zone and the lead
mineralization within these aulacogens. (After Burke &
Dewey 1973 and Mitchell & Garson 1976.)
11. Fig 4. Distribution of carbonatite
intrusions relative to the East
African Rift Valley
(After Mitchell & Garson 1976)
• Volcanism in the rifts is usually of alkaline type,
sometimes with the development of carbonate
lavas and intrusives and occasionally kimberlites.
• Erosion of these may lead to the formation of
soda deposits (e.g. Lakes Natron and Magadi in
East Africa) and the intrusive carbonatites may
carry a number of metals of economic interest as
well as being a source of phosphorus and lime.
Ambadongar, which is a famous carbonatite
Complex, Newania carbonatite complex (Apatite
and REE), Rajasthan,
Sevathur carbonatite (Vermiculite)complex,
Tamilnadu.
11
Mineralization associated with continental rifting
12. 2. Ocean Basins and Rises
Volcanogenic Massive Sulphides.
• Massive sulphides deposits are currently forming in undersea locations
characterized by “Black Smokers”. These Black Smokers are plumes of
sulphide-rich fluids and represent the venting of hydrothermal fluids, rich in
base and precious metals, onto the ocean floor.
12
• Eg- Base metal deposits of
Ambaji and Deri in Delhi Fold
Belt, Rajasthan.
Fig. 5 Diagram showing how sea water circulation through
oceanic crust might give rise to the formation of an
exhalative volcanic-associated massive sulphide deposit.
13. 13
Cyprus Type Massive Sulphide Deposit
• Cu-Fe rich associated with ophiolites and represent hydrothermal
deposits formed at ocean ridges.
• They are typically underlain by copper-rich "stringer-zones" composed
of anastomosing quartz-sulfide mineral veins in extensively chloritized
basalt
• Hydrothermal mineralization with the development of Cu, Zn, Ag and
Hg have been reported from oceanic ridges in the Atlantic and Indian
Oceans by Dmitriev et al. (1971)
14. 3. Passive Continental Margins
• Passive continental margins develop along coastlines that are not
tectonically active.
• Passive continental margins that have suffered marine transgressions are
important for phosphorite deposits.
• Coastlines marked by considerable upwelling are favourable sites for
phosphogenesis e.g., Miocene phosphate deposits of south – eastern
continental margin of USA.
• Important beach placer deposits are developed along the trailing edges
(passive continental margins).
• Placer deposits include: diamond placers of the Namibian coast, the rutile-
zircon-monazite-ilmenite deposits of the eastern and western coasts of
Australia.
• Eg- Beach Placer Deposits of Western Coast of India
14
15. (a) Nutrient rich, deep ocean water floods
on to the continental shelf and low grade
phosphorite deposits form
(b) A sea level rise leads to a major marine
transgression resulting in a reworking of
phosphorite shelf sediments and the
shoreward transport of phosphatic grains to
form major deposits in the coastal zone and
in marginal embayements. (After Cook
1984)
Possible model for phosphorite formation beside an upwelling site initiated in a deep ocean.
15
Fig 7
16. 4. Subduction-Related Settings
Subduction is a geological process in which the oceanic lithosphere and some
continental lithosphere is recycled into the Earth's mantle at convergent
boundaries.
Subduction can produce Island arc or continental margin arc.
Mineralization in Island arcs
• Ocean lithosphere is subducted beneath an overlying plate composed of
oceanic lithosphere produce an island arc
• Series of volcanoes that lies on the continental side of an oceanic trench of
a lithospheric plate. 2 types of deposits
i. Allochthonous Deposits
ii. Autochthonous Deposits
16
17. Allochthonous Deposits
• Rocks and Minerals deposits initially formed at the Mid Oceanic Ridge will
ultimately reach the subduction zone.
• Some of the material will get subducted some, however, is obducted to
form accreted terrain.
• Cyprus-type massive sulfide ore bodies thrust into a mélange, occur in
north western California.
• Podiform chromites are the most important magmatic deposits in the
allochthonous peridotites. The chromites are cumulates that originated in
the upper mantle, often at mid-oceanic ridges.
17
18. 18
Fig 8 Ore deposits associated with island-arc and adjacent regions. (Source: Evans, 2009)
19. Autochthonous Deposits
• 3 Stages
1) Initial or tholeiitic stage :- Considerable sedimentation and subaerial
volcanicity may have occurred during the tholeiitic stage. No major Ore
deposits.
2) Main calc-alkaline stage.:- main island arc building and plutonic igneous
activity belong to this stage.
• Volcanic massive sulphide, stockwork, skarn and vein deposits are formed
in this stage. Conformable sulphide ore bodies of Besshi-type develop at
this stage in back-arc basins.
• Sillitoe (1972a) suggested that the solutions which deposited some of
these massive sulphide deposits might have come directly from subducted
sulphide bodies
19
20. 3) Waning calc-alkaline stage:- The massive sulphide deposits of Kuroko-type
probably belong to the later stages of development of island arcs.
• They are associated with the more felsic stages of calc-alkaline magmatism.
• Kuroko-type ores in ancient island arcs include the Paleozoic deposits of
Captain's Flat, New South Wales; Buchans, Newfoundland; Parys Mountain,
Wales; and Avoca, Iceland.
• Present opinion is that these deposits too are wholly or mainly developed
in back-arc settings
20
21. (a) Ocean-ocean convergence
producing island arc volcanoes and
backarc basins.
(b) Ocean—continent convergence
producing continental volcanic arcs.
(Courtesy of the US Geological
Survey.)
21
Fig 9
22. Continental Margins
• Continent – ocean convergent margins, where continental margin volcanic
arcs develop on the overlying continental lithosphere.
• Partial melting of a thick overlying wedge containing continental lithosphere
produces the calc - alkaline series that include andesitic, dacitic, basaltic
and rhyolitic rocks.
• Ore Deposits here are associated with volcanic arc magmatism.
• These deposits are caused due to progressive liberation of metals from the
descending slab.
Example-
Along the Circum-Pacific Belt major metallic deposits occur in western North
and South America, Japan, Philippines, New Zealand and Indonesia
Porphyry Copper Deposits of Malajhkhand, India( ?)
22
23. 23
In the Andes, going from west to east, the various zones encountered are:
a) Contact metasomatic Fe-deposits;
b) Cu-Ag and Ag veins;
c) Porphyry Cu-Mo deposits;
d) Pb-Zn-Ag veins and contact metasomatic deposits; and
e) Sn deposits.
Fig 10
24. .
• Relatively narrow and sub vertical wrench zones along which two adjacent
blocks move sideways, horizontally, parallel to the strike of the fault zone.
• Transform faults are, however, loci of higher heat flow and could well be
channel-ways for hydrothermal solutions, as certainly appears to be the
case in the Red Sea.
• Donnybrook-Bridgetown Shear Zone of western Australia, which is
considered to be analogous to the San Andreas Fault System, hosts the
Greenbushes pegmatite group (Sn-Ta- Li producer) which is potentially the
largest rare metal resources in the world.
• Gold deposits in Archaean Abitibi Greenstone belt of Ontario-Quebec
(Canada) exhibit close connection with regional fault zones.
24
5. Strike Slip Settings
25. 6. Collision Related Settings
• When a continent on the subducting plate meets either a continental
margin or island arc on overriding plate.
• Subduction can then lead to melting in the heated continental slab and the
production of S-type granites or I type granite.
I - type granites are generated by the melting of an igneous protolith from
either the downgoing oceanic lithosphere or the overlying mantle wedge.
• Porphyry copper, tungsten and molybdenum deposits are associated with I
- type granites.
Eg:- Permian volcanic-plutonic arc with a porphyry copper deposit at Loei.
25
26. S - type granites are produced by the melting of sedimentary crustal rocks in
collision zones.
• Tin deposits are associated with S - type granites.
• Uranium deposits, particularly vein type, may be associated with S-type
granites as in the Hercynides and Damarides (Rossing uranium deposit,
Namibia).
• Eg- In the foreland molasse basins, uranium mineralization is
reported from the Siwaliks in India and Pakistan.
• Tin Tungsten deposit of Chhendapathar, West Bengal.
26
27. Fig 11 (a) Two continents on a collision course as oceanic crust between them is
subducted. Here we have the Andean-type situation of Fig. 23.5 in which I-type
granites are generated along the Benioff Zone. Some of these granites may host
porphyry copper deposits.
27
28. Fig 11 b) Collision has taken place and the leading section of the underriding plate has
been blanketed with thick thrust slices of sediment and mélange. Temperatures rise
sufficiently in this continental crust to permit partial melting and the formation of S-type
granites. If the crustal material contained above average amounts of tin, tungsten, etc.,
then these granites may have associated, epigenetic deposits of these metals. The I-type
and S-type granites, with their associated mineralization, may occur in parallel belts as in
Thailand and Malaysia. (After Beckinsale 1979.)
28
29. Conclusion
• Ore deposits are formed in various environments.
• These environments in some way or other are related to plate
tectonics.
• Predication and Correlation of various ore deposits can be done
using Plate Tectonics.
29
30. References
1. Evans, A. M. (1992): Ore geology and Industrial Minerals, Blackwell Science.
2. Hefferan, K and O’Brien, J (2010): Earth Materials, Wiley Blackwell.
3. https://www.degruyter.com/document/doi/10.1515/geo-2020-0007/html.
4. https://epgp.inflibnet.ac.in/epgpdata/uploads/epgp_content/S000448GO/P00
0596/M018265/ET/1482317225MAINTEXT.pdf
5. https://epgp.inflibnet.ac.in/epgpdata/uploads/epgp_content/S000448GO/P00
0596/M018266/ET/1482317287MAINTEXT.pdf
6. https://egyankosh.ac.in/bitstream/123456789/58973/3/Block-4.pdf
30
Back Arc Basins:- Back-arc basins (BAB) are extensional basins formed behind subduction zones by rifting and in some cases, seafloor spreading developing on the overriding plate.
The volcanic regions above the porphyry systems are also the sites of epithermal precious metal mineralization(gold).