This document discusses metamorphic differentiation, which refers to the redistribution of mineral grains or chemical components within a rock during metamorphism. There are two main types - segregation, which produces mineral-rich layers, and compositional layering parallel to metamorphic foliation. Gradients in chemical potential that drive differentiation are created by factors like temperature differences, pressure differences, mineral composition, mineral size, and the surrounding media. Mechanisms of differentiation include preserving original layering, transposing original bedding, solution and reprecipitation of minerals, preferential nucleation of minerals in fluids, and migmatization involving partial melting.
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:
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:
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
The name ophiolite derived from Greek root which means
Ophio : snake or serpent Litho : Stone
The green colour, structure and texture of sheared ultramafic rocks is similar to some serpents
Economically :
Massive Sulphide
It founded within pillow lava most of massive Sulphide associated in ophiolites have well developed Gossans (bright colored iron oxide, hydroxides, and sulfides) which is very rich in gold.
Chromite
Stratiform (be tabular or pencil shape) or podiform (irregular shape) within ultra-mafic rocks
These deposits are developed on serpentinite peridotite
Laterites (nickel and iron)
Asbestos
Talc
Magenesite
ophiolite sequence :
Sediments
Pillow Lavas
Dykes
Gabbros
Layered Gabbro
Layered Peridotite
Upper mantle
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)
Boundary problems between :-
Precambrian/Cambrian
Permian/Triassic
Cretaceous/Tertiary
Neogene/Quaternary
Stratigraphic boundaries are determined by one or more of geological events such as volcanic activity, sedimentation, tectonism, paleo-environments & evolution of life.
Faunal records have played major role in determining the boundaries of the Phanerozoic units.
The other geological events are dated on the evidence of fossil records.
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.
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
The name ophiolite derived from Greek root which means
Ophio : snake or serpent Litho : Stone
The green colour, structure and texture of sheared ultramafic rocks is similar to some serpents
Economically :
Massive Sulphide
It founded within pillow lava most of massive Sulphide associated in ophiolites have well developed Gossans (bright colored iron oxide, hydroxides, and sulfides) which is very rich in gold.
Chromite
Stratiform (be tabular or pencil shape) or podiform (irregular shape) within ultra-mafic rocks
These deposits are developed on serpentinite peridotite
Laterites (nickel and iron)
Asbestos
Talc
Magenesite
ophiolite sequence :
Sediments
Pillow Lavas
Dykes
Gabbros
Layered Gabbro
Layered Peridotite
Upper mantle
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)
Boundary problems between :-
Precambrian/Cambrian
Permian/Triassic
Cretaceous/Tertiary
Neogene/Quaternary
Stratigraphic boundaries are determined by one or more of geological events such as volcanic activity, sedimentation, tectonism, paleo-environments & evolution of life.
Faunal records have played major role in determining the boundaries of the Phanerozoic units.
The other geological events are dated on the evidence of fossil records.
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.
metamorphic rocks and their distinguishing features-megascopic and microscopic study of gneiss, schist, quartzite, marble and slate
Properties and characteristics and uses of metamorphic rocks
1- INTRODUCTION In any introductory textbook on physical geology- the.pdfcontact28
1. INTRODUCTION In any introductory textbook on physical geology, the reader will find the
discussion on metamorphic rocks located after the chapters on igneous and sedimentary rocks,
and for very good reason. Metamorphic rocks form by the physical and sometimes chemical
alteration of a pre-existing rock, whether it is igneous or sedimentary. In some cases, even
metamorphic rocks can be altered into a completely different metamorphic rock. With igneous
rocks forming from the melt produced by any rock type and a sedimentary rock forming from the
weathered product of any rock type, the alteration of any rock to produce a metamorphic one
completes the components of what is known as the rock cycle. Basically, the rocks we encounter
today that we classify as either igneous, metamorphic, or sedimentary, could have belonged to a
different rock classification in the past, as rocks are recycled throughout geologic time, driven by
the motion of the tectonic plates. It is easy to see that increasing the temperature of a rock can
produce magma, and that rocks on the surface of the earth can break up into sediment that can
ultimately lithify into a sedimentary rock. But how can we alter a solid rock into a new rock,
without melting it or making it become sediment? All rocks are formed at certain temperatures
and pressures on or more commonly, beneath the earth's surface, and these rocks are the most
stable at the conditions under which they form. Therefore, changing the temperature and/or
pressure conditions may lead to a different rock, one that changed in order to be stable under new
extemal conditions. This new rock that forms in response to changes in its physical and chemical
environment is called a metamorphic rock; the word metamorphism means to change form, and
for rocks this means a recrystallization of minerals (crystals) under subsolidus (temperatures too
low for melt production) conditions. A metamorphic change can also occur if the rock's
composition is altered by hot, chemically reactive fluids, causing a change in the mineral content
of the rock. To distinguish between the pre-existing rock and the new metamorphic one, the term
protolith or parent rock is used to describe the pre-existing rock, and all metamorphic rocks have
at least one protolith that has altered during metamorphism. In this chapter you will learn that all
metamorphic rocks are identified by the mineral content and texture of the rock; for metamorphic
rocks, texture refers to the orientation of the minerals in the rock, although crystal size does
convey important information regarding the temperature conditions during metamorphism. To
summarize, metamorphism is the process by which a pre-existing rock (the protolith) is altered
by a change in temperature, pressure, or by contact with chemically reactive fluids, or by any
combination of these three parameters. The alteration process is a recrystallization event, where
the initial rock's minerals (crystals) have changed size.
This defines summer solstice, winter solstice, autumnal equinox, vernal equinox, perihelion and aphelion position.
Click on the link to watch explanation. https://youtu.be/dRHwnRqzaYY
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.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
insect taxonomy importance systematics and classification
METAMORPHIC DIFFERENTIATION
1. METAMORPHIC DIFFERENTIATION
MID SEM ASSIGNMENT
SESSION – 2019-20
SUBMITTED TO - SUBMITTED BY –
PROF. M.K. YADAV GOPALJI GUPTA
M.SC. 2ND
SEM
ROLL NO. 190014215018
DEPARTMENT OF GEOLOGY
UNIVERSITY OF LUCKNOW, LUCKNOW
2. CONTENTS
1.INTRODUCTION
2.KINDS OF METAMORPHIC DIFFERENTIATION
• SEGREGATION
• COMPOSITIONAL LAYRING
3.FACTORS CONTROLLING CHEMICAL POTENTIAL
GRADIENT
4.MECHANISM OF METAMORPHIC
DIFFERENTIATION
• PRESERVATION OF ORIGINAL COMPOSITIONAL
LAYERING
• TRANSPOSITION OF ORIGINAL BEDDING
• SOLUTION AND REPRECIPITATION
• PREFERENTIAL NUCLEATION
• MIGMATIZATION
3. The most prominent macroscopic structure in regional
metamorphic is a foliation. This is commonly parallel to a
compositional layering and even in coarse grained gneisses,
granulites and charnokites is tacitly assumed to be bedding by
many workers although Not all bendings which are generally
found in the metamorphic rocks like layering, striping or
foliation in schist, gneisses, amphibolites, quartzites and
marble is necessarily relict bedding. It may be an entirely
metamorphic structure due to metamorphic differentiation or
it may be relict bedding which has been folded, transposed and
rotated around to coincide with a metamorphic foliation.
Metamorphic differentiation is a collective term for the
varius processes by which minerals or mineral assemblages are
localy segregated from an initially uniform parent rock during
metamorphism.
As we know that minerals differ in their ability to glide,
thus gneissic or layered ores may develop by metamorphic
differentiation. Thus there is development of pseudo-
stratification by the metamorphic differentiation process.
Metamorphic differentiation is redistribution of mineral
grains and/or chemical components in a rock as a result of
metamorphic processes. Metamorphic process by which
mineral grains or chemical components are redistributed in
4. such a way to increase the modal or chemical anisotropy of a
rock (or portion of a rock ) without changing the overall
composition of the rock.
Metamorphic differentiation appears to act contrary to most
metamorphic processes which tends to flatten out chemical
gradients. It involves an increase of order from more
disordered, homogeneous material and thus a decrease in
antropy.
There are two kinds of metamorphic differentiation which are
most important are –
1.Segregation under low to high pressure, but no direct
pressure, to produce segregates rich in one or more
minerals. The chemical concentration results from
gradients in chemical potential due to pressure
differences, to some original chemical discontinuity, to
difference in grain size and shape, to differences in ionic
migration and to other lesser known factors.
5. 2.The formation of a compositional layring parallel to a
metamorphic foliation. The layring is due to segregation
of light coloured minerals such as quartz and feldspar on
one hand, and of dark coloured mineral such as biotite,
hornblend, pyroxene, epidote, garnet etc. on the other.
This layring occurs in mylonite and is very comman schists.
Massive igneous rocks pass into layered greenschists and
amphibolotes
The gradients in chemical potential are created by 5 main
factors which are as follows –
1. Differences in Temperature
2. Differences in Pressure or non-hydroststic stress
3. Differences in the chemical composition of
minerals
4. Differences in the size of minerals
5. Differences in the surrounding media
6. There are several mechanisms to explain the
metamorphic differentiation.
1.Preservation of Original Compositional Layering. In
some rocks the compositional layering may not represent
metamorphic differentiation at all, but instead could
simply be the result of original bedding. For example,
during the early stages of metamorphism and
deformation of interbedded sandstones and shales the
compositional layering could be preserved even if the
maximum compressional stress direction were at an
angle to the original bedding.
In such a case, a foliation might develop in the shale
layers due to the recrystallization of clay minerals or the
crystallization of other sheet silicates with a preferred
orientation controlled by the maximum stress direction.
7. Here, it would be easy to determine that the
compositional layers represented original bedding
because the foliation would cut across the
compositional layering.
2.Transposition of Original Bedding. Original
compositional layering a rock could also become
transposed to a new orientation during
metamorphism. The diagram below shows how this
could occur. In the initial stages a new foliation begins to
develop in the rock as a result of compressional stress at
some angle to the original bedding. As the minerals that
form this foliation grow, they begin to break up the
original beds into small pods. As the pods are
compressed and extended, partly by recrystallization,
they could eventually intersect again to form new
compositional bands parallel to the new foliation.
8. 3.Solution and Re-precipitation. In fine grained
metamorphic rocks small scale folds, called kink bands,
often develop in the rock as the result of application of
compressional stress. A new foliation begins to develop
along the axial planes of the folds. Quartz and feldspar
may dissolve as a result of pressure solution and be
reprecipitated at the hinges of the folds where the
pressure is lower. As the new foliation begins to align
itself perpendicular to 1, the end result would be
alternating bands of micas or sheet silicates and quartz or
feldspar, with layering parallel to the new foliation.
9. 4.Preferential Nucleation. Fluids present during
metamorphism have the ability to dissolve minerals and
transport ions from one place in the rock to another.
Thus felsic minerals could be dissolved from one part of
the rock and preferentially nucleate and grow in another
part of the rock to produce discontinuous layers of
alternating mafic and felsic compositions
5.Migmatization. As discussed previously, migmatites are
small pods and lenses that occur in high grade
metamorphic terranes that may represent melts of the
surrounding metamorphic rocks. Injection of the these
melts into pods and layers in the rock could also produce
the discontinuous banding often seen in high grade
10. metamorphic rocks. The process would be similar to that
described in 4, above, except that it would involve partially
melting the original rock to produce a felsic melt, which
would then migrate and crystallize in pods and layers in the
metamorphic rock. Further deformation of the rock could
then stretch and fold such layers so that they may no longer
by recognizable as migmatites.