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International Journal of Remote Sensing & Geoscience (IJRSG)
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A NOTE ON BARYTES MINERALIZATION IN
PUNGARH REGION, DISTRICT PALI, RAJASTHAN
Brijendra Singh Gahlot & P. C. Avadich,
Department of Geology, Mohanlal Sukhadia University, Udaipur, Rajasthan.
[email protected]
Abstract
Barytes is an important modern day industrial
mineral. Barytes mineralization is found in
different Precambrian units of Rajasthan.
In Punagarh hill region, barytes mineralization
is hosted by Sojat Formation of Delhi Supergroup.
It occurs as vein deposit showing various forms
viz. linked veins, parallel veins, fan shaped,
chambered vein. Vugs and other cavity filling
textures are also observed associated with
mineralization. The mineralization has undergone
post deposition tectonism as evidenced by
granulation of barytes grains.
The barytes mineralization is epigenetic. The
hydrothermal solutions have been derived from
the Erinpura granite intrusive into Sojat
Formation.
Keywords: Barytes, Delhi Supergroup, Punagarh
Group, Sojat Formation, Epigenetic, veins
Rajasthan (Table 1).The barytes mineralization is
associated with igneous, sedimentary and
metamorphic rocks. It occurs as veins, cavity –
filling, bedded and residual deposits.
Table 1: Association of Barytes mineralization in sub-divisions
of the Precambrian of Rajasthan.
Geologic Unit
Malani
Locality
Karara
District
Jalore
Suite
Vindhyan
Bhander
Supergroup
Group
Delhi
Supergroup
Jogniyamata
Chittorgarh
Rewa Group
Jawarakalan
Punagarh
Punagarh
Group
Hill
Ajabgarh
Alwar &
Sikar &
Group
Rajgarh
Alwar
Pali
belts
Alwar Group
Raialo Group
Hathauri
Bharatpur
Aravalli
Debari
Delwara
Udaipur
Supergroup
Group
region
Ranthambhor
Anupura
Chittorgarh
Rajpura
Dariba-
Rajsamand
Bhilwara
Group/
Rajpura
Supergroup
Jahazpur
Umar
Bundi
Relpataliya
Udaipur
Introduction
Barytes, an important modern industrial
mineral in present day industry. It is mainly used
in oil well drilling due to its high specific gravity,
low hardness, inertness to acids, insolubility in
water and most important its lowest cost compare
to other heavy materials.
In the global scenario India is endowed with
third position in terms of reserves and second in
production of barytes. Mangampet in Andhra
Pradesh is the world’s largest single barytes
deposit with 68.4 million tonnes of recoverable
reserves (IBM, 2015)[1]. In Rajasthan, occurrences
of barytes are known in Alwar, Bharatpur,
Bhilwara, Bundi, Chittorgarh, Jalore, Pali, Sikar,
Sirohi, and Udaipur districts where as important
deposits are limited to Alwar, Bharatpur, Pali and
Udaipur districts. Geologically, barytes is found in
all the major sub-divisions of the Precambrian of
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Group
Group
Mangalwar
Complex
Study Area
The present study area is located 12 km ENE of
the District town of Pali (E 73° 26' 26" : N 25°
48'10") and lies wholly within the scope of Survey
of India topo sheet, No. 45G/5 (Figure 1). Access
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International Journal of Remote Sensing & Geoscience (IJRSG)
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Figure 2: Location map of Study area (part of Survey of India
Toposheet no 45G/5).
Regional Geology of the area
The study area falls in the Delhi Fold Belt and
has been included in Punagarh Group of rocks
(Gupta et al., 1981)[2]. The rocks are exposed to
the west of the Main Delhi Synclinorium and
separated by a stretch of Erinpura granite. The
Punagarh Group overlies the Kumbhalgarh and
Sirohi Groups (Gupta et. al., 1997)[3] and occurs
as a roughly oval shaped outcrop from
Dhangarwas in the north to Bumadra in the south
and from Punagarh in the east to Bhagasar in the
west (Figure 2).
Gupta et al., (1981)[2], has divided the rocks of
the Punagarh Group into four formations namely
Sojat, Bambholai, Khamal and Sowaniya
Formations. The Punagarh Group comprises
slates, phyllites and quartzites of Sojat Formation
with synsedimentational basic volcanics of the
Bambholai, Khamal and Sowaniya Formations.
The Bambholai Formation is characterized by
synsedimentational pillow basalt of tholeiite to
alkali basalt type. Similarly the basic volcanics of
Khamal Formation have been identified as having
alkaline character. The synsedimentational
volcanic rock of the Sowaniya Formation is also
tholeiitic basalt.
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Later workers placed the Punagarh Group as
the youngest group in Delhi Supergroup. Gupta
et.al (1981)[2] Roy (1988)[4], Gupta et.al (1995)[5],
Roy and Sharma (1996)[6], Roy and Jahakar
(2002)[7] placed Punagarh Group and its time
equivalent Sindreth Group at a much higher
stratigraphic position whose volcanic phase was
dated 780 Ma (Roy and Sharma, 1996)[6].
Chore and Mohanty (1998)[8] separated the
Sojat Formation from Punagarh Group, containing
bimodal volcanics, volcanoclastics and terrginous
sediments. The contact is marked by shear zones.
An age distinction between the two is indicated by
absence of granite within the Punagarh Group
where as the Sojat Formation containing slates
and phyllites has been invariably intruded by
Erinpura granite (Table 2).
Table 2: Stratigraphic succession of study area (After Chore &
Mohanty, 1998).
Punagarh Group
into the area is by way of National Highway NH14, from where the interior parts of the study area
are linked by minor tar-roads. The nearest rail
links are the stations at Pali, Marwar Junction and
Bumadra, even as the nearest airport is at Jodhpur,
some 60 km to the northwest.
Intrusives
Sowaniya
Formation
Dolerite and felsic dykes
Shale, repetitive sequence
of basalt, rhyolite and gritty
quartzite
Shale, dacite and quartzite
Khamal
Formation
Bambholai Pillowed basalt, jaspery
Formation
quartzite and shale
-------------------Unconformity--------------Erinpura Granite/ Gneiss
Shale, slate and
Sojat Formation
metatuff
Geology of the area
The rocks of the Sojat Formation represented
by a succession of variegated shales, sandy slates,
phyllites, mica schist, ferruginous and brecciated
quartz-rock at places cherty and minor dolomite.
The soft and easily amenable to erosion viz. slate,
phyllites and mica schist are generally exposed in
the plains.
Near Sojat and Punagarh Hill, the rocks due to
the hard rock capping are still preserved on
hillocks. The ferruginous and brecciated quartzrock at places cherty occurs as irregular lenses and
veins within the slates and phyllites along the
western flank of the Punagarh Hill (Figure 3). The
rock is light-grey to spotted and brownish in color
and consists of opalescent quartz, light- to pink
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Figure 3 Simplified regional geology of the Study area (Modified after Chore and Mohanty -1998) showing the
distribution of various units in Punagarh Group of Delhi Supergroup.
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color and at few places yellow colored barytes,
red jasper, limonite and hematite. Besides
smaller veins, there are about 16 lenses of 35
cm to 12 m in width and maximum of 500m in
length.
rock indicates a zone of shearing. The general
trend of this shear zone varies from N10° to
30°E and S10° to 30°W and is parallel to N20°40°E and S20°-40°W.
Nature of Mineralization
Figure 3: Geological map of the Study area.
Structure
The area forms a doubly plunging syncline,
with two closures, one located near Punagarh
hill in south and the other at Khamal in the
north. The syncline plunges at moderate angle
(250- 300) towards NNE and SSW. The
attitudes are variable due to folding and the
regional strike is NNE- SSW. Bedding is well
seen in slates. The dip varies 10°-80° towards
east or west according to the limbs of the folds.
The slates in the area are highly folded and
both macroscopic and microscopic folds are
found. In the Punagarh Hill area itself are two
anticlines and a syncline. These folds are
asymmetrical and trend in NE- SW direction.
They plunge at 10°-60° towards south-west.
Axial plane foliation is well developed. The
general trend varies from N20°-40°E - S20°40°W with high dips,
mostly 60°-80
towards east. The brecciated quartz-barytes
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The barytes occurs as irregular lenses, thick
massive veins, or in the form of small veinlets,
long rod shaped grains and stringers along the
foliation plane/ joints and fracture planes in
brecciated quartz barytes rock and at a contact
of slates (Plate 1). A total of 34 lenses and veins
of barytes were observed and most of them are
clustered in the western flank of the Punagarh
hill. The thickness of the mineralization zone
varies from 2 to 10 meters. The thickness of the
individual barytes vein varies from 2 cm to 25
cm, while length of the individual vein extends
up to 5 meter. At few places barytes veins runs
parallel and at different orientation (Plate 2) and
shows angular relationship with each other. The
general trend of these barytes veins are N20-400
W but few are trending N20-600E.
The important mineralization structures
observed in the area are as follows;
Veins: A tabular or sheet like body of mineral
which has formed along fissures in rocks.
Fractured filled veins are produced where the
mineralization has occurred along narrow
openings.
Linked veins: When individual fractures are
linked by diagonal veinlets, they are called
linked veins (Plate 3).
Fan shaped: When veins radiating from one
base and spread like fan (Plate 4).
Chambered veins: when the walls of fissures
are not straight and parallel but are irregular and
brecciated. The fragments of different shape and
size of the host rock are caught up in
mineralization. The caught up fragments may
have orientation differing from the host rock.
Such veins are known as chambered veins
(Plate 5).
Crustified veins: successive deposition of one
or more mineral crusts on two walls of fissure
opening gives rise to crustified veins. The first
formed minerals will be deposited on the vein
walls followed by successive minerals layers
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towards the centre of the cavity. Usually an
irregular opening or vug left at the centre (Plate
6).
The barytes is fine to coarse grained and
massive. At times crystalline variety is also
observed. The color varies from white to off
white, bright grey and pink, and at some places
yellow in color. Lustre is vitreous to earthy. The
crystalline variety is translucent. Rarely
transparent variety is also observed. Under
microscope the coarse grain barytes appears
cloudy.
The minerals associated with barytes are
mainly pyrite, galena, chalcopyrite with little
calcite, hematite, magnetite, iron oxide and
stains of malachite developed randomly. Thick
veins and patches of hematite/ iron oxides are
also observed. The brecciated rock, at places,
shows limonitic box work (Plate 7), probably
after the sulphide mineralization (galena and
pyrite).
Most of the field samples of the ferruginous
brecciated quartz- barytes rocks at places cherty
are medium grained mainly composed of
barytes 70%, quartz 25%, opaques 5%. The cut
surface shows long rod shaped grains and
patches of white barytes lying in association of
grayish black, fine to medium grained galena.
Number of very thin veins of hematite criss
crossing the rock. The overall grain size of the
rock is fine to medium grained. Coarse grained
barytes is seen on the uncut surfaces.
Barytes
It occurs as very coarse grains showing long
tabular, columnar, wide columnar, coarse
lozenge shaped grains joined to each other
forming a large size mass. It also occurs in
cavity as parallel rods showing equal width or
tapering at one end, lies attached to sulphides
(Pyrite etc.) on both the ends. The barytes fills
up the cracks and interspaces between the
broken pyrite. Here the barytes is folded and
curved.
Under cross nicols it shows a very high
degree of undulatory extinction in all the grains.
The barytes also shows polysynthetic twining.
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The large size barytes grains are surrounded by
abundant fine to very fine grained grains of
barytes showing different shapes viz. rod
shaped, semi round or square shaped, all knitted
and joined together (Plate 8). High RI of barytes
distinguished it from the quartz grains. The
coarse grained columnar laths invariably show
two sets of well-developed cleavages lying at
right angles to each other numerous thin cracks
are seen in grains along with black and earthy
powdery material and opaques as inclusions in
it. Inclusions of quartz grains are also present in
barytes mass.
The opaque minerals viz. pyrite, galena,
hematite are fine to medium grained. The grains
show different shapes and sizes. Numbers of
fracture filled veins of iron oxide of varying
thickness cut across the whole thin section. The
veins are curved and parallel and vary in
thickness and lie joined to each other. The veins
cut across the grains of barytes. The outlines of
veins are highly serrated. Rectangular, cubic
and round shaped grains of pyrite in association
with barytes are observed.
Genesis
The investigation in the present study area
reveals the following characteristics of the
barytes occurrence;
(i) It occurs as various types of veins criss
crossing the slate and brecciated quartz
barytes rock.
(ii) The veins show various structures of cavity
filling, chambered veins, linked veins, and
crustified veins.
Based on the study of mode of occurrences,
mineralization
textures,
structures
and
petrography, it can be concluded that barytes in
Punagarh area is epigenetic hydrothermal vein
and cavity filling type deposit.
In the present area of investigations the
possible source of hydrothermal solutions could
be Erinpura granite. The mineralizing solutions
have been derived as the last phase of igneous
intrusion. Barium with other metal ions and
sulphur ions has been carried in solution.
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International Journal of Remote Sensing & Geoscience (IJRSG)
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While moving along various openings in the
rocks, this hydrothermal solution mixed with
other circulating fluids viz. meteoric, connate
waters etc. has been oxidized. The barium and
sulphate ions combined to form barium sulphate
(BaSO4). This solution sulphate upon reaching
the solubility limits precipitated as barium
sulphate i.e. barytes in veins and other openings
available in rocks of the area, along with other
associated minerals. The present relationship of
barytes mineralization is the result of various
post depositional tectonic events in the area.
Plate 2: Quartz-barytes rock with different orientation of
barytes veins.
Acknowledgments
We deeply acknowledge to the facilities
provided by Prof. T. K. Pandya, Head,
Department of Geology, Prof. Vinod Agrawal,
Chairman, faculty of earth science, Mohanlal
Sukhadia University Udaipur and Prof. Harsh
Bhu for their support and help to prepare this
research work.
Plate 3: Linked veins of barytes in slate.
Plate 4 : Fan shaped barytes veins in slate.
Plate 1: Showing long rod shaped grains and patches of
white/ brown color is barytes in association with brownish
black colored hematite.
Plate 5 : Showing chambered veins.
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References
[1] Anon. IBM, (January 2015): Indian
Minerals Year Book- 2013, Part IIIMineral Reviews, 52nd addition
[2] Gupta, S.N. Arora, Y.K. Mathur, R.K.
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Sharma, S.B., (1981): Lithostratigraphic
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[3] Gupta, S.N. Arora, Y.K. Mathur, R.K.
Iqballuddin, Prasad, B., Sahai, T.N. And
Sharma, S.B., (1997): The Precambrian
Geology of the Aravalli Region, Southern
Rajasthan and Northeastern Gujarat, Mem.
Geol. Surv. India, 123, 262p.
Plate 6 : Crustified quartz- barytes veins with vugs.
[4] Roy, A. B., (1988): Introduction, In: A. B.
Roy (ed.), Precambrian of the Aravalli
Mounatin, Rajasthan, India., Mem.. Geol.
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Plate 7: Boxwork after sulphide leaching in cherty- quartzbarytes rock.
Plate 8: The extremely large size barytes grains are
surrounded by abundant fine to very fine grained grains of
barytes showing different shapes viz. semi round or square
shaped, all knitted and joined together with undulatory
extinction.
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