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.
STUDY OF IMPORTANT METAMORPHIC ROCKS.pdfRITISHASINGH7
Study of important metamorphic rocks-
Petrological Characteristics, Indian Stratigraphic Position, Locality, Economic Importance and Facts about -
Granulite, Charnockite,
Eclogite, migmatites, Khondalite, Gondites.
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.
STUDY OF IMPORTANT METAMORPHIC ROCKS.pdfRITISHASINGH7
Study of important metamorphic rocks-
Petrological Characteristics, Indian Stratigraphic Position, Locality, Economic Importance and Facts about -
Granulite, Charnockite,
Eclogite, migmatites, Khondalite, Gondites.
A presentation on Hydrothermal wall rock alteration with case studies on geophysical applications.
References : https://drive.google.com/drive/folders/16VSZMPMASMNVB47JdBUa_7udBk1qvK2U?usp=sharing
Gravity anomaly across reagional structuresAmit K. Mishra
Gravity Anomaly across continents and ocean, gravity anomaly across mid-oceanic ridges, gravity anomaly across orogenic belts, and gravity anomaly across subduction zones.
Kutch is an East-west Oriented pericraton Rift basin Situated between Nagar Parkar Fault in North and Kathiawar Uplift in South.
Here we will discuss Geology and its Sequence Stratigraphy.
A presentation on Hydrothermal wall rock alteration with case studies on geophysical applications.
References : https://drive.google.com/drive/folders/16VSZMPMASMNVB47JdBUa_7udBk1qvK2U?usp=sharing
Gravity anomaly across reagional structuresAmit K. Mishra
Gravity Anomaly across continents and ocean, gravity anomaly across mid-oceanic ridges, gravity anomaly across orogenic belts, and gravity anomaly across subduction zones.
Kutch is an East-west Oriented pericraton Rift basin Situated between Nagar Parkar Fault in North and Kathiawar Uplift in South.
Here we will discuss Geology and its Sequence Stratigraphy.
La minería de cámaras y pilares se realiza en secciones, paneles que habitualmente son rectangulares y regulares en un planos. Se utiliza en minerales duros mediante la distribución de leyes en el cuerpo mineralizado.
Guía practica e inicial para entender la formación de yacimientos minerales y la relación de los procesos geológicos formadores de las rocas con las acumulaciones de minerales con alta rentabilidad en su explotación que el hombre hace hoy.
Lithology, Structure and Geomorphology of the Nagari outliers, Chittoor distr...iosrjce
Nagari Quartzite of the Nallamali Group of the Cuddapah Supergroup occurs as outliers in the
southern end of the Cuddapah basin. These are also called Nagari outliers named after the type area of Nagari
Quartzite. All the Nagari outliers exhibit a sequence of basal conglomerate, grit and quartz arenite/quartzite.
Conglomerate is mature and an oligomictic one with the pebbles of quartzite dominating over the chert, quartz,
jasper and vein quartz with siliceous and ferruginous matrix. The clasts in the southern part of the outlier of Sri
Kalahasti have been subjected to shearing resulting in the elongation of pebbles. The grit unit is similar to
conglomerate in composition, but the grains are sub-rounded to angular, medium to coarse grained and set in a
siliceous matrix. The quartzite unit in the Nagari outliers is predominantly fine grained quartz arenite and
occasionally ferruginous in nature. Fining upward of this sequence can be easily recognised in this unit. There
are a number of mini and intermediate cycles, the former is less than half- a- meter and the latter is up to 1
meter in thickness. The varying thickness of the quartzite in different outliers can be considered as a major
cycle. These outliers reflect 2nd order topography. This also exemplifies one of the fundamental concept of
geomorphology that “lithology and structure control the evolution of land forms” put forward by Woolridge.
The major land forms that are clearly visible, even from a distance are the escarpments and cuestas. The hills
are synclinal in structure and are made up of highly resistant quartzite. The intervening valleys that are
anticlinal have granite in the core. The relative competency has played a major role in carving out the mature
topography. It is evident that the synclinal structure that has developed at the time of formation has been refined
by the subsequent tectonics, resulting in the formation of synclinal hills
Carbonatite Bombs, Lapillus, Pisolites And Ashes In Semi-Unconsolidated Congl...IJERA Editor
Occurrence of sediments hosted smooth surfaced flat / discoid black and pink coloured bimodal carbonatite bombs, lapillus, pisolites and ashes in semi-unconsolidated conglomerate covering an area of 90 sq.km is reported from Thiruvalangadu (13o10’36”N-76o44’38”E) area situated 60 km WNW of Chennai. The carbonatite materials are uniformly composed of flow-oriented fine-grained calcites <0.02>< 1mm dimensions filled with recrystallized relatively coarse-grained calcites (~0.1mm). These rocks are essentially composed of calcite with accessories of apatite, augite, hornblende, biotite, wollastonite, skeletal sanidine, sodic oligoclase and corroded quartz. These rocks have significant amount of silica and alumina. Their Fe3+/Fe2+ is greater than 1. The pink variety contains K2O> Na2O. Mafic minerals are alkalic in nature. The low values of ∂13CPDB (from -8.2 to -5.5‰) in black carbonatite and in pink carbonatite (from -5.2 to 0.10‰) and high values of ∂18OSMOW (from 23.1 to 23.7‰) for block carbonatites and (from 24.4 to 27.63‰) for pink carbonatites indicate extensive degassing and loss of volatiles and alkalies by exhalative eruption of these lavas.
An Account of Field and Petrographic Characteristics of Granitic Rocks of Che...ijtsrd
Field geological and petrographic characteristics of granitic rocks of Cherlapally area, Nalgonda district, Telangana, within the eastern Dharwar craton are described in this paper. Field traverses revealed four types of granitic rocks in the study are viz., quartz diorite, granodiorite, monzogranite and syenogranite. The variations in the texture and mineralogical composition of these plutons are so distinct that the term migmatite' has to be applied, wherein mutual field relations always remain enigmatic. The complex nature of the batholiths is also evident from the structural fabrics observed in the present investigation. N. Ningam | P. R. C. Phani "An Account of Field and Petrographic Characteristics of Granitic Rocks of Cherlapally Area, Nalgonda District, Telangana" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25202.pdfPaper URL: https://www.ijtsrd.com/other-scientific-research-area/geology/25202/an-account-of-field-and-petrographic-characteristics-of-granitic-rocks-of-cherlapally-area-nalgonda-district-telangana/n-ningam
Petrological and Geochemical Studies on Granitoids in BibinagarBhongir Area, ...IJERA Editor
The Granitoids of the Bibinagar- Bhongir area in the Nalgonda district are purely high potassic calc alkaline and
meta aluminous and A-type belongs to Peninsular Gneissic Complex of the Eastern Dharwar Craton. The
petrographic study of granitoids indicates that of pure magmatic origin in the form of different magmatic
textures viz. perthitic, porphyritic and poiklitic textures. Geochemically the granitoids are rich in K2O & Na2O
suggesting source from calc-alkaline magma. The Granitoids are falling mostly in the volcanic arc field on Yb
vs Ta discrimination plot. The REE pattern shows strong Eu negative anomaly, suggesting early separation of
plagioclase and the enhanced level of LILE relative to HFSE in Bibinagar-Bhongir granitoids points to the
subduction zone enrichment and/or crustal contamination of the source region.
Heavy Mineral Studies of Beach Sands of Vagathor, North Goa, IndiaIJMER
Vagator beach is situated 22 km away from panjim on the northern side Bardez taluk
approachable via Candolim are Mapusa by road. The beach is projected on both the sides by
promontories. The beach is in arcuate shape, the area included with survey of India toposheet No
48/E/14 which is bounded by latitudes 15º35ˈN 15º38ˈN and longitude 78º43ˈE. The Chapora river
and its tributaries drain the entire region that is the Vagator beach. It flows from North-East to
South-West direction. The drainage pattern is structurally controlled; the Chapora River has its
source in the Ramghat hills of Belgaum district in Karnataka then it flows through the Thilari ghat
and enters Goa. Its length in Goa is about 31 km and the mouth of the river bank, mud bank and
mangroves swamps are common.
In laboratory techniques heavy mineral separation are based mass separation in a liquid
with specific gravity and magnetic separation using hand magnet and Frantz isodynamic separator
at different volts. X-ray analysis was carried out by using RIGAKU ALTIMA IV copper target on the
basis of Bragg’s law. The non magnetic sand grains was observed under optical microscope to
identify diagnostic properties of minerals.
The heavy mineral shoot comprises of opaque (magnetite and illmenite) and transparent heavy
minerals like hornblende, epidote, garnet, rutile, zircon, enstatite and minor amounts of tourmaline.
The light minerals are mainly quartz and feldspars. The magnetite concentration ranges between 2.01
to 56.86% and Ilmenite between 2.83 to 41.04% and non mangnetics between 1.18 to 44.81%. X ray
diffraction studies and SEM (Scanning electron microscope) studies were employed to study the
mineralogical composition of beach sands of Vagator and detailed investigations are dealt in the
paper.
Occurrences of asbestos, vermiculite, corundum, magnesite and talc, are typically associated with Pan-African ultramafic rocks such as peridotite, serpentinite, gabbro, and norite.
Migif-Hafafit area in the Eastern Desert of Egypt contains asbestos-vermiculite deposits at several sites, occurs in the magnesium-rich metapelitic schist-ultramafic complex.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
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.
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.
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.
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 .
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Richard's aventures in two entangled wonderlandsRichard 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.
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.
1. Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN2249-9598, Volume-IV, Issue-I, Jan-Feb 2014
w w w . o i i r j . o r g I S S N 2 2 4 9 - 9 5 9 8 Page 115
Petrographic Study around Vallanadu Area, Tuticorin District,
Tamilnadu, India
a
Manimaran D, a
Besheliya J, a
Manimaran G
a
Department of Geology, V.O.Chidambaram College, Thoothukudi-628008, Tamilnadu,
India
Vallanadu area of southern Granulite terrain forms an Achankovil shear zone.
Charnockites, khondalites, cordierite gneisses, calc-silicate rocks and grey and pink
granite are the main lithotypes. The study highlights petrography, modal based
geochemistry, shears and joints of the area. Two sets of conjugate shear system are
observed. Ductile natured NW-SE dextral shear conjugating with NE-SW sinistral
subordinate shear and brittle-ductile natured NW-SE to WNW-ESE achankovilsinstral
shear conjugating with N-S dextral subordinate shear are identified. Granites of the area
are of syntectonic origin. Vallanadu area of Achankovil shear zone suffered by initial
ductile deformation followed by brittle-ductile deformation during the uplift and collision
tectonics of Neoproterozoic to Cambrian time.
KEYWORDS: Vallanadu, Petrography, Joints, Modal analysis, Achankovil shear zone,
Southern Granulite.
INTRODUCTION
The Vallanadu area is a high grade metamorphic terrain of almandine amphibolite
to granulite facies and forms a part of Achankovil shear zone. The area is essentially
comprised of different lithotypes i.e., quartzites, calc-silicate rocks, khondalites,
composite gneisses, cordierite gneiesses, charnockites, greygranites and pink granites and
veins of pyroxene granulites and amphibolites (Manimaran 2012; Manimaran and
Manimaran 2013). Achankovil shear zone (ASZ) is well studied in Kerala region while
in Tamilnadu region detailed study are yet to going on (Santosh, 1984, Srikandappa etal
1985; Chacko etal 1987; Santosh and Drury 1988; Ramakrishnan, 1993; Manimaran and
Roy Chacko, 1996; Rajesh etal 2001; Ravindrakumar and Subash Sugumaran, 2003;
Cenki and Kriegsman, 2005; Guru Rajesh and Chetty, 2006; Manimaran 2009;
Manimaran and Manimaran 2013). Recently collisional suture natured tectonics status
was established for ASZ through geophysical deep electrical studies by Dhanujaya Naidu
etal 2011; and from seismic reflectivity studies on southern granulite terrain by Rajendra
Prasad etal. 2007. The texture and mineral Content of the rocks of the area are well
studied to establish Petrography and petrogenesis of the vallanadu area. Thin section and
megascopic studies of the rocks and Modal content of the rocks are studied. The modal
analysis of six important rocks of the study area have been studied and their chemical
constituents (average) of the rocks were derived from modal analysis and C.I.P.W. norms
and Niggli values were calculated, and variation diagrams and chemical discriminate
plots were constructed so as to establish the petrochemical characteristics and
relationships of the various lithounits of the study area (Fig.1) were delineated.
Abstract
2. Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN2249-9598, Volume-IV, Issue-I, Jan-Feb 2014
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LITHOLOGY AND FIELD RELATIONSHIPS
ROCKS OF KERALA KHONDALITE BELT
Khondalites of vallanadu area of Kerala Khondalite Belt (KKB) are represented
by pelitic, Semipelitic, psammitic and calcareous members. The distribution of various
lithotypes of the area is shown in Fig.1a.
QUARTZITES
The psammitic members of KKB are represented by the quartzites and are mostly
granular and massive in appearance. They occurs bands and veins in both gneisses and
charnockites of the area. South of Vallanadu isoclinally folded quartzite occur within the
host of garnetiferous biotite sillmanite gneiss. Intercalation of small bands and veins of
calc-granulites are noticed admist quartzites. Quartzite exposures are occurring at
Vallanadu, east of Seydunganallur, south of Rajagopalapuram and Rajavallipuram. The
general trend of the quartzites is NNW-SSE to NW-SE with variable dips. A quartzite
band at north of Vallanadu occur at the junction among granites, charnockites, cordierite
gneiss and garnetiferous biotite sillimanite gneiss.
CALC-SILICATE ROCKS (CALC-SILICATES)
The calcareous members are represented by calc-granulites, calc-gneisses,
limestones and dolomitic limestones. Linear ellipsoidal band of calc-silicates occur at
palamadai, east of Rajavallipuram and Maruvathalai, east of sivalaperi. Limestone is
essentially composed of calcite with minor minerals of sphene, spinel and graphite. The
calc-granulites and calc-gneisses are manily represented by calcite-wollastonite, diopside
and quartz –wolanstonite – calcite – grossularite and Clinopyroxenes mineral
assemblages. At places scapolite and chondrodite are also noticed in the field.
GARNETIFEROUS BIOTITE SILLIMANITE GNEISSES AND GARNET
BIOTITE GNEISSES
The pelitic and semipelitic members of KKB are represented by graphite bearing
garnetiferous biotite sillimanite gneisses and Garnet biotite gneisses respectively. The
foliations are entirely due to the presence of alternating layers of quartz and feldspars
rich, biotite rich, sillimanite rich zones. Biotite rich layers is from 1cm to 10 cm;
Quartzofeld spathic rich layer is from 1cm to 50cm; sillimanite layer 2cm to 16cm thick
are noted in the field. Imperceptible gradation between garnetiferous biotite sillimanite
gneiss and garnet biotite gneiss and at places biotite-poor leptinitic variety (acid
khondalite), Garnet sillimanite gneiss (white and yellow) is also occur. At places, bands
veins and patches of incipient charnockites are noticed in garnet biotite genisses.
CORDIERITE GNEISSES
Cordierite gneisses are exposed at paraikulam, vasavappapuram,
Rajagopalapuram, Papayankulam, Ganagaigondan (Railway station), Maruvathalai and
Anavaradanallur.The bluish violet, pearly sheen cordierite formed as idioblastic clots and
crystals. Cordierite formed as rich layers and biotite is associated with cordierite rich
layer 1cm to 6cm thick cordierite rich layers are foliated alternately with
quartzofeldspathic layer and depletion of garnet content in cordierite rich layer is
common. Cordierite gneisses developed in the host of garnetiferous gneisses and
charnockites are observed. Band and veins of basic granulites and grey and pink granites
are also observed within the country rocks of cordierite gneisses. Cordierite gneisses are
showing sinistral shearing plans along NW-SE direction, which are parallel to
Achankovil shear zone.
3. Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN2249-9598, Volume-IV, Issue-I, Jan-Feb 2014
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CHARNOCKITES
The massive charnockite exposures are exposed at Timmarajapuram and KTC
Nagar, southeast of sivalaperi; Gangaigondan, Maruvathalai, singattakurichi and NE of
Vallanadu area. It dark green glistening rock having hypersthene as a essential mineral
occuras dark green porphyroblastic crystals. Bands, veins and lenses of basic granulites,
grey and pink granites are common in charnockites. At places near pegmatite intrusions,
the breaking of the charnockite leads to rertograde gneisses evolved from charrockites are
also encountered in the field. Relic patches of garnet biotite gneisses in charnockite, at
contact abrupt warpping of the gneissic foliation at the boundary of charnockite suggest
that the charnockites of the area is subsequent to khondalites and the pelitic genises of the
area were transformed into charnockites.
BASIC GRANULITES
The basic granulites are essentially consists of orthopyroxenes (hypersthene) and
clinopyroxenes (Diopside and Augite), hence the name two-pyroxene granulites. They
occur and associated with all types of rocks of the area and usually as small veins and
lenses in the country rocks of khondalites, quartzites, cordierite gneisses and
charnockites.
GRANITES
The Granites and pegmatites are of in two colours-gray and pink. A large grey
granite band of 1km breadth and 10km length intruded the major isoclinal fold of
vallanadu is traced in the field. The other bands of granite are occur at west of Vallanadu
and east of Sivalaperi at Maruvathalai. The composite gneisses are having veins and
bands of grey as well as pink granites. Since granites intruded all lithotypes it is the
youngest rocks of the area.
COMPOSITE GNEISSES
It is a special kind of rock yielding black soil of the area due to its high Mg and
Ca contents. It is mainly represented by graphite bearing garnetiferous biotite gneisses
showing multi intercalations of veins and bands of calc-silicate rocks, incipient
charnockites, basic granulites, granites and pegmatites. calc-silicate rocks and basic
granulites are also play vital role in the genesis of black (cotton) soil due to their Ca and
Mg bearing minerals. At places, composite gneisses were intruded by lit-par-lit Injection
of grey granites and grey pegmatites and bands of charnockites and basic granulites were
retrograded into regressive gnesisses. The overall multi kind network lithology status of
the rock assigns the name composite gneisses.
PETROGRAPHY AND MICROTECTONIC FEATURES
QUARTZITES
Quartzite shows granular texture and Varieties include white, Milky, Rosy and
Smoky. In general quartzites are feldspathic, ferruginous (haematite and Ilmenite)
bearing quartzite running like a linear band. At vallanadu, quartzites occur in the core of
a isoclinal plunging major fold. The modal content of the quartzite is as follows: Quartz
93.2; graphite 2.5; Biotite 1; Ilmenite 1; apatite 0.25 and plagioclase 2.
Microphotograph (Fig.4.1) shows fluid inclusions bearings (H2O + CO2) quartz grains of
a quartzite.
CALC-GRANULITE
They are dark green coloured with white sacchoroidal grains of calcite and quartz.
The following mineral assemblages are traced from thin sections.
4. Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN2249-9598, Volume-IV, Issue-I, Jan-Feb 2014
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i) Calcite – Wollastonite – quartz – diopside and
ii) Calcite – Wollastonite – scapolite – diopside.
Graphite, ilmenite and sphene are occurring as minor minerals. Scapolite occurs as
prismatic crystals with cleavages intersecting at 90o
and 45o
and it show second order
interference color and straight extinction.
GARNET BIOTITE GNEISSES
The gneissic textured garnet biotite gneisses show mineral assemblage of
plagioclase (An 25 – 35 oligoclase and andesine composition) + Orthoclase +quartz +
garnet + biotite + Graphite ± sillimanite ± cordierite. The biotite flakes define the
foliation and planar fabrics of the rocks. Garnet occurs as irregular and idioblastic grains.
Biotite occurs as irregular plates and laths and is strongly pleochroic from dark brown to
light brown. At places, they are perthitic in nature. The average modal content of garnet
biotite gneiss is as follows quartz 34.18; orthoclase 5.29; plagioclase 19.01; microcline
3.85; garnet 12.03; biotite 12.76; perthite 7.22; Magnetite 3.61 and apatite 2.05.
CORDIERITE GNEISSES
The well foliated cordierite gneisses shows alternating foliations of Cordierite
rich, biotite rich and quartzofeldspathic are common. Cordierite rich zones are generally
depleted in garnet. The modal content of Cordierite gneiss of Maruvathalai is Quartz 7;
Orthoclase 5; Plagioclase (An 25) 5.25; Perthite 1; biotite 4; Cordierite 29; Magnetite 14;
Apatite 14; Ilmenite 2 and Hypersthene 30.
The photomicrograph (fig.2) shows large porphyroblastic, twinned Cordierite
associated with minerals of biotite, hypersthene, orthoclase, quartz, sillimanite,
plagioclase and ilmenite crystals. The above equilibric minerals assemblages suggest the
following equation.
Biotite + sillimanite +Quartz = Cordierite + Spinal + Orthoclase + ilmenite
The above assemblage is noticed in cordierite gneisses associated with garnet
biotite sillimanite gneisses. Hypersthene showing ‘S’ pattern alignment and in contact
with quartz and cordierite and garnet inclusions suggest the following decompression
reaction.
Garnet + Quartz = Hypersthene and Cordierite
The above assemblages are traced in the cordierite gneisses associated with Charnockite
and garnet biotite gneisses.
Cordierite gneiss at Ariyakulam under thin section (fig.3) shows sinistrally
deformed and displaced biotite flakes. Near shear the quartz grains are also seen. The
above features suggest the genesis of Cordierite gneisses are related to the Sinistral
shearing of Achankovil shear event.
The cordierite gneiss at Paraikulam shows (fig.4) relic of garnet in neomineralized
biotite. Two generation of biotite is common. A sinistrally deformed cordierite gneiss at
Ariyakulam depicts (fig.5) sinistrally deformed biotite plate. The adjoining sheared
garnet show retrogression and garnet is converted into green colored chlorites along the
shear planes. The material migrations of quartz along the shear planes are also seen.
Fig.6 reveals mineralized and shear localized quartz micro rods along the shear planes. A
sinistrally sheared biotite is on the right side also visible (location: Ariyakulam). A major
cordierite grain at Ariyakulam shows (fig.7) stretched (interference color of dark grey)
orthoclase feldspar and the pattern of stretching suggest a dextral shearing and the photo
micrograph (fig.8) also shows a stretched orthoclase displaying ‘Z’ vergence also
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pointed out a micro dextral shearing of cordierite gneiss suggest that the area was also
suffered through conjugate shearing.
CHARNOCKITE
Charnockite shows both granulitic as well as gnessic texture. Massive and
incipient Charnockites are also common in the area. Incipient Charnockite are in the host
of Cordierite biotite gneisses, Cordierite gneisses and in composite gneisses. Whereas the
massive charnockites are exposed at KTC Nagar, Timmarajapuram, Sivalaperi and north
of vallanadu. The modal content of massive charnockite of KTC nagar , Quartz 20.39;
Orthoclase 4.65; Plagioclase 4.47; perthite 65.18; apatite 2.25; ilmenite 0.17;
Hypersthene 2.50 and zircon 0.39. The modal content of incipient charnockite of
pallamadai is as follows: Quartz 13.48; orthoclase 17.13; plagioclase (An 50); Biotite
16.04; garnet 19.10; Magnetite 3.65; apatite 1.68; Hypersthene 7.58 and chlorite 1.12.
At places, in the field observation the incipient charnockite shows discernible
megascopic garnet and quartz yielding corditerite and hypersthene equilibric assemblages
are also noticed from gneisses with intimately associated incipient charnockite
quarries(Paraikulam quarry).
Garnet + Quartz = Cordierite + hypersthene
The photomicrograph of Akkanaikkanpatti(fig.9 ) shows a gnessic charnockite showing
stretched quartz, hypersthene and biotite and feldspars. The retrograded and non-
retrograded original hypersthene of charnockite is discernible. From the field it is known
that the location is intruded by pink granite.
COMPOSITE GNEISS
The composite gneiss essentially composed of Khondalites intruded by many veins
and bands of grey pegmatites and pink pegmatites, sills and dykes (now bands of
pyroxene granulites) of basic sills. A composite gneiss (fig.10) showing garnet, biotite,
quartz, feldspar and apatite. The altered composite gneiss (fig.11) at Keelapuvani shows
Fluorite, biotite and kaolinized feldspars. The composite gneiss at Lakshmipuram
(fig.12) shows sinistrally sheared biotite and quartz ribbons suggest the existence of
Achankovil shear zone upto Lakshmipuram.
GRANITES
Megascopically Granites of Vallanadu are classified into two types, namely grey
granites and pink granites. The Vallanadu grey granite forms as an axial plane intrusion
of the major Vallanadu quartzite isoclinal Fold (Fig.1). It is also seen at east of
Vasavappapuram and at Maruvathalai. Mode of occurrence of Granites is of two types 1.
Linear band and 2. Foliation guided granite veins. Intrusions of pink granite veins are
observed in charnockites, all gneisses and also grey granites.
The grey granite band of Vallanadu shows the modal contents – quartz 49.5;
orthoclase 23.89, plagioclase 15.27, Biotite 6.18, Magnetite 1.28, Apatite 1.66, chlorite
1.07, zircon 0.37 and sphene 0.78. A grey granite vein associated with incipient
charnockites in cordierite gneisses shows the following mineral assemblages – quartz
56.59, orthoclase 7.96, plagioclase 2.74, perthtie 28.57, apatite 0.27, chlorite 0.58 and
Fluorite 3.29.
The pink granite of Akkanaiyakkanpatti shows the modal content of quartz 38.81,
orthoclase 23.43, plagioclase 8.46, perthite 17.39, zircon 0.72, apatite 3.88, chlorite 1.30,
fluorite 3.95, magnetite 0.99, Ilmenite 0.27, biotite 0.27 and sphene 0.61. Fig.13 the pink
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granite shows oriented apatite grains in quartz and feldspar. The pink granite clearly
shows (fig.14) the mineralization of newly forming quartz grain along the mineral
borders of perthite, quartz and feldspar suggest insitu melting due to shearing of mineral
grains. The pink granite (fig.15) shows fluorite, magnetite, apatite and quartz. Fluorite
partly isotropic and partly optically showing anomalous interference colors. Crystals of
fluorite are ubiquitous in Akkanaiyakkanpatti pink granites exposures. The perthite of
the pink granite shows sheared rods of perthite and left stepping of newly formed lense
shaped sodic plagioclase from the sheared rods of sodic plagioclase suggest that the rock
experienced a sinistral shearing (fig.16).
KANKAR
The composite gneisses of Puliyampatti reveal conjugate microshear fractures in
quartz and feldspar (fig.17) and they were converted into kankar formations. The fig.18
shows concretionary kankar formation around a pore space developed in composite
gneiss due to meteoritic water perculations. Also the fig.19 exhibits a filamentous kankar
formed along the gneissic foliations of composite gneisses country rock. Black soil
invariably originated from composite gneisses of the area. At Kilpuvani the composite
gneiss shows (fig.20) the development of calcrite formation due to alteration of
plagioclase feldspar. Kaolinised orthoclase and chloritised biotite are also visible.
The lithotypes of the study area are well displaying microshear features viz. shear
fractures, sinistral and dextral shearing and conjugate shearing. The dominantsinistral
shear pattern suggests that the area belongs to part of Achankovil shear zone and
boundary of the shear zone should be located beyond North to the present study area.
PETROCHEMISTRY
MINERALS
The modal percentage of various minerals of the selected rocks types around
vallanadu are presented in the table 1. Examination of the table reveals that the most of
the rocks of the area have modal quartz more than 10% (acid type). Cordierite gneisses
were formed from shearing and decompression reactions of khondalitic gneisses and
charnockites. There is a general reduction in the modal abundance of biotite in massif
charnockite than the associated cordierite gneisses while in the incipient charnockites
modes of biotite are almost higher in the particular sample due to intrusion of grey
granites and retrogression of incipient charnockites. The depletion of garnet in Cordierite
gneisses and Charnockites are pointing out decompression and shear related origin from
the earlier Khondalitic gneisses. The modal quartz of granites are varies from 38 to 16%
suggest they are derived from salic enriched source.
GEOCHEMISTRY
Mineral Modal based major oxides of the selected six rocks of the vallanadu area
are tabulated in the tables (table 1-8). The estimated Niggli values are given in table 9.
The variation diagram plotted for sio2 versus oxides figures 21, 22 and 23 shows weak
linear relationship for the rocks of the Vallanadu area suggest they are mostly derived
from a Para type-sedimentary provenance, suggest that they are Metasedimentary with
some igneous component.
The plots (Fig.24) versus Na2O K2O the rock types of Vallanadu area fall in
Granite-Adamellite fields Where as the Cao versus K2O plot (fig.25) fall in the field of
Tonalite- Granite field suggest the para-provenance source for these rocks were highly
silicic source i.e. proterozoic in age. The K2O-Na2O-Cao plots (fig.26) fall in the fields of
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Granite to Tonalite also pointing the same sialic source for the lithotypes. The Niggli
variation diagram (Fig.27) constructed for the major oxides versus SiO2 suggest pacific
suite for these rocks. The SiO2 versus Na2O+K2O (Fig.28) fall in the field of calcic. The
calcic and pacific suite nature of the rocks reflects that the sediments were partially
produced from Archaean-terrain also i.e. North of Palaght-Cauvery shear zone (or)
Archaean terrain of SriLanka and Madagascar during the late proterozoic time which
were formed as contiguous land during the formation of Gondwana Land.
TECTONIC STUDIES
FOLIATION
The gneisses of khondalites are usually well foliated and their foliation is essentially
parallel to the bedding. The foliation planes are two to three millimeter apart in the fine
grained types and in the layers of garnet rich and cordierite rich zones it is 1cm to 1m
apart. Abrupt warpping of gneissic foliation at the sharp contact of charnockite and also
the continuity of same gneissic pattern (foliation) in charnockite of diffuse contact zones
are encounter in the field. At places, grey granites and pink granites show faint foliation
due to the orientation of tiny crystals of biotite. The general strike of foliation displayed
by the rocks of the area is mostly from NW to SE and the amount of dip varies from 15°
to 85° towards South West. At hinges of khondalite folds show foliation striking either
N-S with easterly dip or E-W with northerly dip.
LINEATION
The observed linear elements are usually the mineral lineations and axes of the
megascopic folds. In the gneissic of Khondalites, spangles of biotite, needles of
sillimanite and in charnockites, the oriented laths of feldspars and hypersthenes are
developed as mineral lineations. The mineral lineation of sub-horizontal plunging and
vertical lineations are also observed in the field. Based on the pattern of fold axes, the
study area is divided into four different structural domains for tectonic analysis (Fig.29).
FOLD PATTERNS
The well-banded gneissic pattern of the area display both major and megascopic folds
and crenulations. Intra-folial isoclinals folds of gneissic bonding are common, although
their hinges do not define a simple systematic orientation and probably reflect near
plastic deformation. The folded quartzite veins are of tight and open types and the strike
of the axial planes of the fold varies from N-S to NE-SW. The quartzite hillock of
Vallanadu shows a northwesterly moderate plunging, isoclinals overturned anticline fold
(Fig.1). The area is a part of Achankovil sinistral shear zones. Apart from NW-SE
sinisterly shears the gneisses of the area exhibits conjugate shear bands systems of an
earlier NW-SE dextral conjugating with NE-SW sinistral followed by overprinting of
NW-SE sinisterly conjugating with N-S dextral shears.
JOINTS
The area is mainly traversed by strike joints running parallel to NW-SE and dipping
steeply towards SW and are well developed in all litho units expect in granites. Steep N-S
joints dipping east and NE-SW joints dipping NW are the other master joints observed
in the field.
For tectonic analysis the study area is divided into four blocks based on the mineral
lineation and fold axes observed i.e. Block I Vallanadu, Block II RajaGopalapuram,
blockIII Rajavallipuram and block IV Akkanayakkanpati. For each block the observed
joint readings like strike and pole to the attitude of the joints are plotted in the equal area
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contour plots and rose diagrams as Fig.30 a, b; Fig.31 a, b; Fig. 32 a, b and Fig.33 a, b
respectively. The above plots reveal in all blocks joints are radiating almost in all
direction and are dipping steep to moderate nature and six sets of joints are delineated
from the area and are given in order of prominence.
• NW-WNW to SE-ENE dipping SW with steep to moderate dips.
• NW-WNW to SE-ENE dipping steep NE.
• NE-SW dipping moderate to steep NW.
• NE-SW dipping SE.
• N-S to NNW-SSE group dips easterly.
• E-W to ENE-WSW group dips steeply north.
Apart from the above master joint systems minor joints and gush joints of different
orientations are observed at places, from various litho units of different blocks.
The megascopic interpretation of Achankovil shear zone in satellite imagery displays
en-echelon pattern of lineament with right overstepping arrangement, which can be
interpreted as an evidence of the latest Sinistral transpersonal deformation [Guru Rajesh
and Chetty,2006). Manimaran, (2009) identified three-dimensional finite stain pattern
from gneissic rocks of Tenkasi-Ambassamudram region and suggest Transpressive nature
of Achankovil shear zone during the late Neoproterozoic to Cambrian time.
CONCLUSION
Based on the field and petrography evidence delineated from Vallanadu area rock
types the geological history is established. As a part of Kerala Khondanlite Belt, the
Vallanadu region commences with the depositions of varied sediments of regional
metamorphism due to the Lit-par –Lit emplacement of granite material derived from
sialic crustal source which is now represented by Khondalitic group of rocks.
Subsequently, the basic sills were intruded the knondalitic rocks which are now
represented by basic granulites seen in all litho types of the area. During Achankoil
sinistral shearing CO2 rich fluids were migrated from deep crustal source and syntectonic
cordierite gneisses, incipient charnockites were formed. Last phase of syntectonic event
of granite intrusions into the earlier country rocks and regressive Changes were brought
about in the earlier rocks.
Joints/fractures of the area were originated from shears and extension tectonic
origin. Tectonically the Vallanadu region was experienced a series of sub-horizontal
compression of N-S and NE-SW, directions during its earlier ductile regime and the area
was subjected to a later ENE-WSWhorizontal compression during the event of uplift and
brittle deformation.
Acknowledgement
The authors are thankful to Shri.A.P.C.V.Chockalingam, Secretary, Dr.C.Veerabahu,
Principal and II M.Sc. Geology students (2009-2010), V.O.Chidambaram College,
Tuticorin.
REFERENCES
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Granulite Terrain, South India. Precambrian Res. V.138, p 37-56.
Chacko, T. Ravindrakumar, G.R and Newton, R.C (1987) Metamorphic P.T
conditions of the Kerala (South India) Khondalite belt, a granulite facies Supra
crustal terrane Jour, Geol V.95, pp. 343-358.
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Dhanunjaya Naidu, G., Manoj, C., Patro, P.K., Sreejesh V. Sreedhar and
Harinarayana, T. (2011) Deep electrical signatures across the Achankovil Shear
Zone, Southern Granulite Terrain inferred from Magneto tellurics. Gondwana
Res. V.20, p.405-426.
Guru Rajesh, K. and Chetty, T.R.K. (2006) Structure and tectonics of the
Achankovil Shear Zone, Southern India, Gondwana research, v.10, pp 86-98.
Manimaran, D (2012) Groundwater Geochmistry Study Using GIS in and Around
Vallanadu Hills, Tamilnadu, India , Research journal recent sciences V.1(7), p 52-
58.
Manimaran, D and Manimaran, G (2013) Arsenic contamination of groundwater
in Vallanadu region of Ttuticorin district, Tamilnadu, India, Online international
interdisciplinary research journal, v.III, p230-242.
Manimaran, G. (2009) Three-dimensional finite Strain Pattern from Achankovil
Transpression Zone, South India. Outreach v.2 pp. 70-75.
Manimaran, G. and Roy Chacko, P.T. (1996). Shear lineaments and tectonic
setting of Massive and incipient charnockites of Tambraparni shear zone southern
India. In: Ram Mohan, V. (Ed). International symposium on charnockite and
graulite facies rocks, Aug. 1996. Abstract, Univ. of Madras, Madras, India, pp.12-
13.
Rajendra Prasad, B., Kesava Rao., Mall, D.M., Koteswara Rao, P., Raju, S.,
Reddy, M.S., Rao, G.P.S., Sridhar, V. Prasad, A.S.S.R.S., (2007) Tectonic
implication of seismic reflectivity pattern observed over the Precambrian southern
Granulite Terrain, India. Precambrian Res. V.153, p.86-98.
Rajesh, V.J., Arima, M. and Santosh, M., 2001. Geology of the Achankovil Shear
zone, southern India Gondwana Research 4, 744-745.
Ramakrishnan, M. (1993). Tectonic evolution of the granulite terrain of Southern
India. In: Radhakrishna, P.B. (Ed.), Continental crust of South India, Jou, Geol.
Soc. India Memoir No.25, pp.35-44.
Ravindrakumar.G.R. and Subbash sugumaran(2003). Petrology and Geochemistry
of gneiss, charnockite and charno-enderbite of palghat Region, southern India. In:
Ramakrishnan,M.(Ed.), Teckoincs of southern Granulite Terrain, Memoir 50.
Geol.Soc. of India pp. 409-434.
Santosh, M. and Drury, S.A. (1988). Alkali granites with Pan-African affinities
from Kerala, South India. Jou. Geol. V.96. pp.616-626.
Santosh, M. (1984) Fluid inclusions petrography of Charnockites form the
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Srikantappa, C., Raith, M. and Spiering, B. (1985). Progressive charnockitisation
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pp.1-10.
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TABLE 6: COMPOSITE GNEISS – MODAL ANALYSIS
Minerals Volume %
Specific
Gravity
Weight Weight %
Approximate
Weight %
Quartz 33.33 2.65 88.32 32.58 33
Orthoclase 34.35 2.55 87.59 32.32 32
Plagioclase 18.26 2.65 48.38 17.85 18
Apatite 3.48 3.20 11.13 4.11 4
Magnetite 0.24 5.20 1.24 0.45 1
Perthite 5.71 2.56 14.61 5.39 5
Ilmenite 2.55 4.5 11.47 4.23 4
Biotite 0.26 3.10 0.81 0.29 0
Albite 0.31 2.63 0.802 0.29 0
Zircon 1.45 4.6 6.67 2.46 3
271.02 99.97 100
TABLE 7: GARNET BIOTITE GNEISS – MAJOR ANALYSIS
Minerals Volume %
Specific
Gravity
Weight Weight %
Approximate
Weight %
Quartz 10.79 2.65 28.59 10.38 10
Orthoclase 9.72 2.55 24.79 9.00 9
Plagioclase 9.04 2.65 23.96 8.70 9
Biotite 3.49 3.10 10.82 3.93 4
Calcite 47.84 2.71 129.65 47.07 47
Magnetite 2.46 5.20 12.79 4.64 5
Apatite 1.58 3.20 5.06 1.84 2
Enstatite 1.15 3.21 3.69 1.34 1
Limestone 0.86 2.32 1.99 0.72 1
Kaolin 13.05 2.61 34.06 12.37 12
275.4 99.94 100
TABLE 8: Major constituents of various rocks of Vallandadu area
Oxide
s
Pink
granit
e
Cordierit
e gneiss
Charnockit
e
CORDIERIT
E
GNEISS
COMPOSIT
E
GNEISS
garnitiferro
us
biotite gneiss
SiO2 73.84 70.88 76.78 59.04 75.02 24.64
Al2O3 6.45 11.61 4.38 13.12 0.8 15.4
Fe2O3 1.0 - 2.5 - 0.5 2.5
FeO 1.5 2.62 5.75 7.28 2.5 3.08
MgO 0.4 5.91 2.75 9.18 - 0.79
CaO 7.08 3.48 4.5 4.52 5.25 26.63
Na2O 1.56 1.06 1.13 0.56 1.44 0.56
K2O 3.81 2.71 1.0 2.38 4.31 1.42
P2O5 1.25 0.25 0.75 0.5 1.0 0.5
F2 2.0 - - - - -
H2O 0.32 1.42 - 2.0 - 0.58
CO2 - - - - - 24
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TiO2 0.83 - 0.5 1.5 2.0 -
TABLE 9: NIGGLI VALUES FOR VARIOUS ROCK TYPES
OXIDES Si al fm alk C
Pink granite 413.09 21.14 14.42 22.15 42.28
Cordierite gneiss 290.88 28.07 45.32 11.33 15.27
Charnockite 384.38 12.91 54.35 8.70 24.02
Cordierite gneiss 171.13 22.43 57.56 5.91 14.08
Composite gneiss 443.26 27.65 14.53 24.46 33.33
Garnet biotite gneiss 55.09 20.24 12.73 3.21 63.80
Figure 1
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Figure 1a Figure 2
Figure 3 Figure 4
Figure 5 Figure 6
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Figure 7 Figure 8
Figure 9 Figure 10
Figure 11 Figure 12
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Figure 13 Figure 14
Figure 25 Figure 36
Figure 17 Figure 48
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Figure 59 Figure 20
Figure 21
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Figure 22
Figure 23
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Figure 24 Figure 25
Figure 26
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Figure 27
Figure 28
Figure 29
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Fig.30 (a) (b) Fig.31 (a) (b)
Fig. 32 (a) (b) Fig.33 (a) (b)
.
CAPTIONS
Fig.1 Study area
Fig.1a Lithotypes
Fig.2 Cordierite
Fig.3 Biotite flakes
Fig.4 Garnet
Fig.5 Sinisterly deformed biotite flakes
Fig.6 Four generation of quartz in cordierite gneiss
Fig.7 Altered hypersthenes, perthite, quartz and potash feldspar.
Fig.8 Altered hypersthenes under crossed nicols.
Fig.9 Charnockite.
Fig.10 Charnockite under crossed nicols.
Fig.11 Granite-feldspathic material through shear planes.
Fig.12 Grey granite-graphite within the feldspar-sinistral shearing.
Fig.13 Pink granite
Fig.14 Pink granite with shearing of mineral grains.
Fig. 15 Pink granite with fluorite
Fig.16 Rod perthite with sinistral shearing
Fig.17 Composite gneiss
Fig.18 Concretionary kankar
Fig.19 Filamentous kankar
Fig.20 Calcrite formation
Fig.21 Variation diagram
Fig.22 Variation diagram
22. Online International Interdisciplinary Research Journal, {Bi-Monthly}, ISSN2249-9598, Volume-IV, Issue-I, Jan-Feb 2014
w w w . o i i r j . o r g I S S N 2 2 4 9 - 9 5 9 8 Page 136
Fig.23 Variation diagram
Fig.24 Variation diagram
Fig.25 Variation diagram
Fig.26 Variation diagram
Fig.27 Variation diagram
Fig.28 Variation diagram
Fig.29 Four Tectonic domains based on fold axes
Fig.30 Joints (a) - Equal area contour plot and (b) - Rose diagram
Fig.31 Joints (a) - Equal area contour plot and (b) - Rose diagram
Fig.32 Joints (a) - Equal area contour plot and (b) - Rose diagram
Fig.33 Joints (a) - Equal area contour plot and (b) - Rose diagram