A FIELD REPORT ON GEOLOGICAL FIELD VISIT IN AND AROUND UDAIPUR,

RAJASTHAN

Submitted in Partial Fulfillment of The Requirements for The Award of The

Degree of Masters of Science (Applied Geology)

by

MD ARIB KHAN
Roll No: - 24GLMSA107
Enrollment No: - GM8901

DEPARTMENT OF GEOLOGY
ALIGARH MUSLIM UNIVERSITY,
ALIGARH UTTAR PRADESH, 202002 (INDIA) 2024-25
 ACKNOWLEDGEMENT

It is a matter of great satisfaction and pleasure that I completed my field visit in and
around Udaipur, Rajasthan, for partial fulfilment of my Master of Science degree in
Applied Geology.
First and foremost, I am grateful to The Almighty Allah, whose blessing has brought
this success. Then, I want to express my deep gratitude to my teachers, Professor
Shamim Khan, Dr Mohammad Irfan Ahmad, Dr Mohammad Adnan Qasim and Dr
Naseemus Saba, for being my mentors during this endeavour. Their valuable
comments, advice, instructions and suggestions helped me understand and interpret
geology correctly.
I am also thankful to N.K. Chauhan Sir (former GSI member) for sharing his wisdom in the
field geology
I would also like to thank Qamar Hayat (GSI officer) also alumnus of our department for
giving us our valuable time
Completion of any work provides solace and spontaneous gaiety to the doers.
Successful completion of field visits is a product of the team's strenuous and
continued efforts. However, work can only be completed with the assistance,
encouragement, advice, inspiration and stimulus received from various people during
the work. I feel deeply grateful to those who helped us achieve the field visit and
bring it to fruition. Unfortunately, it is impossible to list them all in this limited space.
I am also thankful to our Chairman, Prof Rashid Umar, thank you for giving us
valuable instruments and transport facilities for our field visit.

MDARIB KHAN
GM8901
24GLMSA107

MSc. 1st Semester, Applied Geology, AMU, ALIGARH

 DEPARTMENT OF GEOLOGY
FACULTY OF SCIENCE ALIGARH MUSLIM UNIVERSITY,
ALIGARH – 202002, UTTAR PRADESH, INDIA

CERTIFICATE

This is to certify that the field report for the “GEOLOGICAL

FIELD VISIT IN AND AROUND UDAIPUR, RAJASTHAN (2024–
25)” submitted by MD ARIB KHAN, is to the best of our knowledge,
his fieldwork carried out under our guidance.

Prof. M. Shamim Khan Dr. M.Irfan Ahmad

Dr. M Adnan Quasim Dr Naseem-us-Saba

 TABLE OF CONTENTS

Day-1 14/12/24 Near Badi Lake

Day-2 15/12/24 Khemli village

Near Debari village

Debari village

Day-3 16/12/24 Jhamarkotra mines

Jhamarkotra village

Geo-heritage site-Stromatolites park

Day-4 17/12/24 Bambolai Hills

Mehrangarh Fort,Jodhpur

Day-5 18/12/24 Dhinkli Village,Udaipur

Kabita Village

5km East of Gogunga

KaliGuman lineament,Udaipur

Near Village Majama

Day-6 19/12/24 GSI training centre,Zawar

Near Ramnath Temple,Tihri River,Zawar

Near Mochia Hill

Day-7 20/12/24 Lasadiya Village

Day-8 21/12/24 Haldi ghati

Sirohi, Rajasthan

Mount Abu
 OBJECTIVE: -
 Locating ourselves on the toposheet with the help of GPS, or in
case if, GPS is not present, then with the help of Brunton
Compass, we need to take forward and backward reading
(taking two reference points which are present on the
toposheet).
 Mapping of lithology and preparation of geological map.

 Measurement of strike and dip with the help of Brunton

Compass (for this, primary need is the identification of
bedding plane).
 Recognition of primary sedimentary structure, i.e., ripple marks,
cross bedding, etc.
 Recognition of structural features, i.e., folds, faults, joints, etc.
Construction of geological history of that area, i.e., order of superposition.
 PROCEDURE OF GEOLOGICAL MAPPING: -
Traversing?

 A line, or a system of lines connecting outcrops or station

where observations are taken.
 The observation at an outcrop involves the measurement of the dip
and strike of the particular beds with a Brunton or clinometer compass.
 A traverse is done by walking a more or less predetermined route
from one point on the map to another, plotting the geology on the way.
 The geology in between traverses is interpolated, using whatever
clues can be gleaned from the topographic map.
 Traversing is predominantly used for reconnaissance work
Traversing across and along strike line:
❖ Objective of a traverse along the strike-
 The distribution of strata.
 Whether the strike curve and so indicate plunging structure.
 Whether the strata are continuous or have been faulted.
 The constancy of the dip of a given stratum.

❖ Objective of a traverse across the strike-

 The breadth of outcrop.
 The nature of folding.
 The position of anticline and syncline.
 Variation in dip.
 EQUIPMENT USED
Topographic Map
A topographic map is a detailed and accurate two-dimensional representation of natural
and human-made features on the Earth's surface.
These maps are used for several applications, including surveying and geological
mapping.
It provides the frame of reference upon which the geologic map is constructed.
A suitable topographic map that can be used for geological mapping is the 1:50,000
scale map published by the Survey of India.

Brunton-Clinometer Compass
 A compass clinometer is a
must- have tool for anyone
working in the field of earth
science or geological
surveying, mapping or
for navigational use.
 The compass performs basic
tasks such as orientation and
taking forward and backward
bearings to mark locations in
topographic or geological
maps of the area under survey.
 Inbuilt clinometers allow
geologists to measure the dip
of rock beds or
the height of geological and geographical features and angles.

 Clinometer is used for measuring dip angle.

 Compass is used for measuring direction (magnetic needle always towards magnetic north)
 Sighting Device is used in taking bearing and hand levelling. The hinge mirror and sight help
in taking bearings of selected points. To measure compass direction, the Brunton is held face
up. It is then levelled by using the circular level bubble.
 Hammer
A hammer is essential for chipping rocks and
collecting samples.
Geological hammer generally has one chisel end
and another flat end. The flat end is used for
breaking rocks, while the chisel end is used for
trimming and sizing the specimen.

Global Positioning System (GPS)

Recent technological innovations, such as space-based
global positioning systems (GPS) and smartphone apps,
have built upon the traditional methods of positioning and
navigation to make these tasks considerably more
accessible, faster, and more precise.

Measuring Tape
 Short, 2 to 5 m length, retracting metal tape
measures are adequate for small-scale work and
graphic logging.
 The retracting metal tapes also have the
advantage that they are stiff and, therefore, can
be used much more quickly to obtain an accurate
measurement of the thickness of the bed by
holding it perpendicular to the bedding.
 Field Notebook
It is used for keeping a record of observations made in the field.

 It should be brief but precise.

 It must contain the following information: -
o The exact location of an outcrop.
o Nature of the rock as seen in outcrop.
o Orientation of rock bed (dip, strike, etc) and other structural features, i.e., Ripple Marks,
Current Bedding, etc
o Location of spots visited.
o Correlation of different types of rocks.

Lead and Color Pencil, Marker, Clipboard, Haversack

 GEOLOGY OF UDAIPUR AND ITS SURROUNDINGS
Udaipur, located in the southern part of the Indian state of Rajasthan, is situated in the
Aravalli Mountain Range. The district surrounding Udaipur is known for its rich
geological diversity and its unique rock formations. This area has a varied geological
history, and the rocks here range in age from over 2 billion years old to relatively young
rocks that are only a few million years old. In this article, we will explore the geology of
Udaipur and the surrounding district in detail.
The Aravalli Mountain Range, which runs through Udaipur and the surrounding district, is
one of the oldest mountain ranges in the world, with rocks dating back more than 2.5
billion years. The Aravallis comprise various rocks, including granite, gneiss, schist, and
quartzite. These rocks have been subjected to intense tectonic activity over millions of
years, forming numerous folds and faults. The Aravalli Range is also known for its
mineral wealth. The region has abundant reserves of minerals such as zinc, lead, copper,
and silver. The zinc and lead deposits in the area are some of the largest in the world, and
mining operations in the region have been active for several decades.
The district surrounding Udaipur is also home to a number of geological formations that
are unique to the area. The Kumbhalgarh Formation, which is exposed in the Kumbhalgarh
Fort area, is a sequence of sandstone, shale, and limestone deposited around 1.6 billion years
ago. Geologists find This formation fascinating because it contains evidence of the first
multicellular organisms that evolved on Earth. Another unique geological feature of the area
is the Debari Quartzite Formation, which is exposed in the Debari area. This formation
comprises quartzite rocks deposited around 1.5 billion years ago. The rocks in this formation
are highly resistant to erosion and have been carved into interesting shapes by the forces of
wind and water. The Udaipur district is also known for its extensive deposits of marble. The
marble quarries in the area produce some of the finest quality marble in the world. The
marble here is predominantly white in color and is used for various purposes, including
flooring, wall cladding, and decorative items. The region around Udaipur is also home to
several lakes, including Lake Pichola and Fateh Sagar Lake. These lakes are believed to have
been formed by tectonic activity, and picturesque hills and rock formations surround them.
The lakes are popular tourist destinations and are known for their scenic beauty.
Aravalli Craton: -
The Aravalli craton is situated on the northwestern edge of the Indian Shield. Its
basement, commonly referred to as the ‘‘Banded Gneissic Complex” (BGC; Ahmad et
al., 2016; Gupta, 1934; Heron, 1953) is overlain by two Proterozoic supracrustal
successions viz. the Aravalli Supergroup (Ahmad et al., 2016; McKenzie et al., 2013) and
the Delhi Supergroup (Ahmad et al., 2016; Deb & Thorpe, 2004). Because of obtrusive
intricate bandings within the gneisses, the basement complex is commonly called the
Banded Gneissic Complex (Ahmad et al., 2019; Gupta, 1934; Heron, 1953).
Neoarchaean magmatic activity in the craton started at 2.6 Ga and continued to ~2.44
Ga (Roy & Kroner, 1996; Wiedenbeck et al., 1996). The Aravalli Craton experienced
tectonothermal events during the Proterozoic orogeny at ca. 1.7 Ga (Ahmad et al.,
2017; Buick et al., 2006). The northern BGC (occurring in the central parts of Rajasthan)
has been reworked during Proterozoic tectonothermal events in the craton (Ahmad et
al., 2019; Roy & Jakhar, 2002; Dharma Rao et al., 2011; Bhowmik & Dasgupta, 2012;
Ahmad et al., 2017). Due to this, the BGC has been classified into the BGC-I and the
BGC-II. The BGC-I (occurs to the east and south of Nathdwara) remained unaffected,
whereas the BGC-II (occurs to the north of Nathdwara) underwent large-scale
reworking and remobilisation during the Proterozoic tectonothermal activity. Tectonic
model is to relate the tectonothermal events at c. 1.85–1.8 Ga, c. 1.72 Ga and 0.95–
0.88 Ga and the development of three sedimentary basins before 1.85 Ga (cf. Aravalli
Basin), between1.8 and 1.74 Ga (Sandmata Basin) and between 1.72 and 0.95 Ga (Delhi
and equivalent Mangalwar Basins) to an evolving geodynamic setting for a period of
over 1 billion years (Bhowmik & Dasgupta, 2012).
BGC-I& BGC-II: -
BGC-I is represented by a collage of lithologies ranging in age from Paleoarchean to
Neoarchean. It comprises Paleoarchean to Neoarchean gneisses 3.3–2.7 Ga (Ahmad et
al., 2019; Gopalan et al., 1990; Roy & Kroner, 1996; Wiedenbeck & Goswami, 1994),
undeformed granitoids ~2.5 Ga (Ahmad et al., 2016; Wiedenbeck et al., 1996),
amphibolites 2.83 Ga (Ahmad et al., 2016; Gopalan et al., 1990) and metasedimentary
rocks. Paleoarchean to Mesoarchean ABG is the most dominant lithology having
tonalite- trondhjemite-granodiorite (TTG; sensulato) composition (Ahmad et al., 2016;
Gopalan et al., 1990; Roy & Kroner, 1996). Metasedimentary rocks in the BGC-I are
represented by quartzites, mica-schists, calc- silicates, iron-stone formations, and
marbles (Ahmad et al., 2016; Roy & Jakhar, 2002; Upadhyaya et al., 1992). This cratonic
block, which acted as a basement for the overlying Palaeoproterozoicsupra crustal
successions of the Aravalli Supergroup, remained largely unaffected by the succeeding
Proterozoic tectonothermal events (Bhowmik & Dasgupta, 2012). The lithocomponents
of the BGC-II yield largely Proterozoic ages ~1.7 Ga (Ahmad et al., 2017; Buick et al.,
2006; Dharma Rao et al., 2011). The BGC-II, which lies in central Rajasthan, based on
contrasting grades of metamorphism, has been sub-divided into the Sandmata
Complex and the Mangalwar Complex (Ahmad et al., 2017; Gupta et al., 1980; Guha &
Bhattacharya, 1995). The Sandmata Complex (SC) extends from Bhinai north to
Sandmata Hill in the south. Metamorphosed to granulite facies, it predominantly
comprises pelitic rocks, leptynites, and charnockites. Calc-silicates, norites, and mafic
dykes form the minor components. The complex is intruded by porphyritic granitoids.
The Mangalwar Complex (MC) is represented by a heterogeneous assemblage of
amphibolite- facies gneisses, metasedimentary rocks (pelites, carbonates, and
quartzites), granitoids and amphibolites (Ahmad et al., 2017; Gupta et al., 1997).
Aravalli-Delhi Mobile Belt: - The ADMB is defined in a general way as the 700 km long,
NNE–SSW trending orogenic belt in north-western India, which is a collage of two
spatially and temporally separate Proterozoic supracrustal belts, namely the Aravalli
and Delhi belts and their variously reworked basement gneisses (cf. BGC)’ (Bhowmik &
Dasgupta, 2012). The Aravalli Mountain Range, with Proterozoic successions of the
Aravalli and Delhi systems (Aravalli Delhi Mobile Belt: ADMB), encapsulates several
independent geo-tectonic domains sharing between them stages of deformation and
metamorphism. The Paleoproterozoic age of the Aravalli Supergroup has been firmed
up with new radiometric dates. Analyses of the Aravalli Craton's available structural
and metamorphic data concerning the mobile belt were analysed (Fareeduddin and D.
M. Banerjee, 2020).

Delhi Supergroup: - The Delhi Supergroup is distributed either in a series of fault-bound

basins in thenortheast part of the Aravalli Mountain Range resting directly on the
basement gneisses (North Delhi Fold Belt: NDFB) or directly overriding the Aravalli
Supergroup of rocks in central and southwestern parts (South Delhi Fold Belt: SDFB).
The stratigraphy of the NDFB is well-constrained, but the physical connection between
the two beltsis conjectural. The SDFB represents a collage of three independent linear
fold belts, each with unique depositional and deformational attributes.
Undifferentiated granitic rocks occupy the terrain between the extreme limits of NDFB
and SDFB. Both NDFB and the SDFB comprise meta-arenites, carbonates, and pelites,
along with sporadic granites and gneisses. South of the main SDFB, an independent and
possibly younger Sirohi basin, represents the final orogenic event in the cratonization
of the NW Indian shield. Geochronological data points to ca 1.72 Ga and ca 1.0 Ga ages
for the collisional orogenies accompanied by polyphase deformation and
metamorphisms (Fareeduddin & Banerjee, 2020).
 DAY- 1 DECEMBER 14, 2024 | Saturday
LOCATION: Badi Lake, Udaipur

 Latitude: 24°37′14.351″ N
 Longitude: 73°37′39.248″ E
 Strike Direction :- 320°N
 Dip Direction :- 50°N
 DIp Amount :- 69°

This spot is the westernmost part of the Udaipur belt. The upper part of the ridge
appears to be well- bedded, while the lower part is highly fractured(Mode-I fracture)
and pulverised (evidence of faulting). Quartzite predominates as the primary rock
type in the observed rock formations. An outcrop of Breccia is also visible at this spot,
an apparent evidence of faulting. Various joint patterns (strike, oblique, dip)
characterise the formation. Here, in this region alternate presence of igneous and
sedimentary rock is observed which is refer to as Syn-Sedimentary Volcanism. The
volcanic rock is present at the boundary
 Spot – 02:
 Latitude: 24°37′01.549″ N
 Longitude: 73°37′32.056″ E

At this spot, the predominant rock types that comprise the observed rock formations
are Quartzite and Amphibolite (metabasalt).
Along the road, around Badi Lake, distinct contacts between Quartzite and
metabasalt came into observation. We traced five of these contacts along the
road. These sharp contacts are compelling evidence for the recurrence of
volcanism and sedimentation processes.Quartzite units, characterised by their
light colour and granular texture, are juxtaposed with darker, fine-grained meta-
basalt layers.
These well-defined contacts provide strong evidence of syn-sedimentary volcanism.
Such a characteristic shows that volcanic activity occurred simultaneous deposition
of sedimentry strata

Metabasalt sharp & well-defined contact

between
Quartzite & metabasalt
 DAY- 2 DECEMBER 15, 2024 | Sunday
LOCATION: Khemli Village, Udaipur
Spot – 01:
 Latitude: 26°57′56″ N
 Longitude: 77°15′18″ E
 Strike Direction :- 330°N
 Dip Direction :- 60°N
 DIp Amount :- 62°

Hilly region on one side and the other side is flat There was a lithological gradational
contact between prior BGC (Banded Gneiss complex) and upper Aravalli. Igneous activity
in the form of a lava flow. Green-coloured schist has also been encountered with Some
amount of garnetiferous mica schist.There is a contrast suggesting structural
discordance some pockets of mines were there in the foothills. On site typical sandstone
is observed with clear evidence of metamorphism. Small pockets of Pyrophyllite is also
observed
 Spot – 02:
 Latitude: 24°36′32.497″ N
 Longitude: 73°49′21.497″ E

This location exhibits a polymictic conglomerate featuring clasts of various sizes and
lithologies, unlike the oligomict conglomerate observed. The clasts are described as
pebbles and cobbles. A key characteristic is the imbrication of the clasts, where they are
flattened and tilted in a consistent direction. This imbrication provides valuable
information about the paleocurrent direction.
Notably, the clast size is significantly larger compared to the previous location. The
Conglomerate is highly deformed in nature.

Imbrications:
Imbrication refers to the preferred orientation of elongated clasts (fragments of rocks or
minerals) within a conglomerate. These clasts are not randomly scattered but lie with
their long axes
tilted in the same direction, resembling overlapping shingles on a roof.
Significance of imbrication:
 Paleocurrent direction
 Depositional environment
 Provenance of clasts
Location-2:-
 Latitude: 24°43′21.745″ N
 Longitude: 73°51′02.095″ E

Flat terrain, exposures of the Banded Gneissic Complex (BGC), the Precambrian
basement complex underlying the Aravalli Mountain Range Prominent disturbed
bands with pink and dark-coloured alternating layers.
Light bands: - dominated by Quartz and Feldspar, indicating felsic composition.
Dark bands: - dominated by Biotite and Hornblende, indicating mafic mineralogy
The BGC in this area serves as the critical basement source for overlying formations
in the Aravalli mountains.
The observed banding, compositional variations, and deformation features provide
valuable insights into the geological history of the Aravalli Craton, including episodes
of sedimentation, metamorphism and tectonic activity.
Structural Features
Sigmoidal Veins with a sinistral sense of shear, as determined by offset markers
within the veins, are observed in the outcrop.
Ptygmatic fold- A prominent ptygmatic fold is present. Light coloured competent
layer is folded within the darker colour incompetent matrix.

Asymmetrical folding:- Asymmetrical folds with sinistral sense of shear.

 Delta structure of Porphyroblasts- It indicates sinistral sense of shear

Volcanic Bomb - Volcanic bombs often contain gas escape structures or gaps, which
are voids or cavities formed during their ejection and cooling processes. These gaps
are indicative of the rapid degassing and cooling that occur as the volcanic bomb
travels through the air.
 Spot – 02:

A dark grey, fine-grained extrusive basalt forms a prominent dike intruding into the
surrounding granite rock. The basalt exhibits a distinct contact zone with the
adjacent granite, characterised by a reddish-brown baked margin. This bake suggests
thermal alteration of the host rock by the hot basalt magma during the intrusion,
supporting the interpretation of the basalt as a post-depositional dike.
 DAY- 3 DECEMBER 16, 2024 | Monday
LOCATION: Jhamarkotra Mines, Rajasthan

 Latitude: 24°29′17″ N
 Longitude: 73°50′18″ E

Jhamarkotra mine is located in the outskirts of udaipur. It is largest open cast mine of
india . It is a phosphate mine managed by Rajasthan state mines(RSM). It belongs to the
Pre-Cambrians. It is divided into 3 parts : Eastern,Central & western. The main mineral of
the jhamarkotra mine is Apatite. The host rock is dolomitic limestone . 90-95 million
metric tone is reserved where 5% P2O5 cutt-off grade. The P2O5 is divided into two parts
HGO( more than 25% of P2O5) and LGO(5%-25% of P2O5). The ore body is present on the
footwall which is around 36° and hanging wall is 42° where the remnants are dumped.
The stripping rate is 1:16. The remaining mine life is around 15 years.
 LOCATION: Jhamarkotra Village, Rajasthan
 Latitude: 24°28′24″ N
 Longitude: 73°52′2″ E

Dolomitic Limestone: The presence of dolomitic limestone suggests a carbonate

depositional environment with some magnesium enrichment. The observed
limestone is impure, the main impurity is of terrigenous material (Silica). Apatite is
also present.

Weathering Features:
Elephant Skin Weathering: The occurrence of elephant skin weathering on the
limestone surface is a characteristic feature of this rock type. This distinctive
texture, resembling wrinkled elephant skin, results from differential dissolution of
the carbonate minerals by weathering processes.
 LOCATION: Stromatolite Park, Rajasthan

Stromatolite Park Jhamarkotra has located about 25 km. southeast on Udaipur-

Salumbar Road. it is the largest & richest deposit of phosphorite associated with
stromatolite. It is another site preserving pieces of evidence of early life on the
earth. The stromatolites occur over a strike length of 15 km in rock phosphate
within the Precambrian Aravalli Supergroup of rocks. The rock phosphate occurs in
dolomitic limestone associated with stromatolites appearing in grey to bluish-grey
color shades and invariable forms and shapes.
 DAY- 4 DECEMBER 17, 2024 | Tuesday
LOCATION: Bambolai Hills,Pali district, Rajasthan
 Latitude: 25°51′48″ N
 Longitude: 73°24′7″ E

The Bambolai Hills, situated in Rajasthan, India, are notable for their Neoproterozoic
continental pillow basalts, which are integral to the Malani Igneous Suite. These
basalts exhibit bimodal volcanism, characterized by both mafic and felsic components,
indicative of an extensional tectonic setting. The pillow structures, formed by rapid
quenching of basaltic lava in subaqueous environments, contain vesicles filled with
jasper—a white to reddish form of silica. The red coloration of the jasper is due to
iron oxidation. Additionally, mural joints, which are fractures that divide the rock into
polygonal columns, are present, further attesting to the unique geological processes
during the Malani magmatism.
 LOCATION: Mehrangarh fort, Jodhpur, Rajasthan

 Latitude: 26°17′53″ N
 Longitude: 73°1′8″ E

The fort is built atop a 120-meter-high hillock composed primarily of rhyolite, a fine-
grained, volcanic rock belonging to the Malani Igneous Suite. This suite represents the
last phase of Precambrian igneous activity in the Indian subcontinent, making it
geologically significant The Malani rhyolite, formed around 680-745 million years ago,
showcases evidence of volcanic activity like welded tuff/ignimbrite (fire rain)
formations.
Unconformably overlying the Malani rhyolite is the Jodhpur Group, a sequence of
sandstone belonging to the Marwar Supergroup.The Sonia Sandstone, forming the
upper layer, is a Paleoproterozoic (around 2.5 billion years old). It is part of the
Proterozoic Jodhpur Group and Marwar Supergroup.

Nonconformity
The nonconformity between the Sandstone and the underlying Malani Rhyolites is
present. This geological contact marks a significant gap in time. The Rhyolites, at
Mehrangarh Fort are characterized by their fine-grained texture and light-coloured
appearance.
They are further characterised by the presence of polygonal joints.
 DAY- 5 DECEMBER 18, 2024 | Wednesday
LOCATION: Dhinkli Village,Udaipur,Rajasthan

 Latitude: 24°39’15”N
 Longitude: 73°44’04”E

This location features an exposure of carbonaceous black shale, a fine-grained

sedimentary rock characterized by its dark colour. The presence of significant carbon
suggests deposition in Reducing conditions.
The distinctive black coloration of the shale is primarily attributable to the abundance of
inorganic carbon.
 Spot – 02: Village Kabita
 Latitude: 24°42’1”N
 Longitude: 73°38’16”E

Boudins: -
Boudin structures were observed within the rock formations. These features indicate
a process of extensional deformation within the competent layers, while the
surrounding less competent material accommodated the stretching by thinning or
shearing.
In an F2 fold boudins are observed in the Hinge zone of the fold
Crenulation cleavage: -
Here, we observed S1 & S2 cleavage
Early cleavage that is S1 is more prominent and closley spaced in S2 cleavage the
space got increased
Closely spaced S1 cleavage suggests a high degree of deformation.
Overprinting the S1 foliation is sparsely spaced S2 Cleavage.
At this spot, we encountered L2 lineation which is formed by the intersection of S1 &
S2
Superposed folding :-
At this, the interference pattern of F2 & F3 was observed (Dome & Basin).
F3 FOLD
 LOCATION: Ghasiyar, Rajasthan

 Latitude: 24°43’05” N
 Longitude: 73°37’57” E

The dominant rock type at this spot is Carbonaceous Phyllite wher alternating
arenaceous and argillaceous bands are present.Traces of Cleavage on Bedding planes
and bedding traces on cleavage plane. Striping lineation is present.
 LOCATION: ,5km East of Gogunda Rajasthan
 Latitude: 24°43’05” N
 Longitude: 73°37’57” E

The rock type is a garnet mica schist, characterised by the presence of micaceous
minerals (likely muscovite and biotite).
S0 folded forming F1 fold. Here L1 is more prominent later on L1 is folded forming L2
lineation which is younger.
 LOCATION: KALIGUMAN LINEAMENT, NEAR SHIV
TEMPLE, UDAIPUR
 Latitude: 24°44′15.079″N
 Longitude: 73°48′22.673″E

At this spot, lies the contact between the Aravalli Supergroup and the overlying Delhi
Supergroup, marked by the prominent Kaliguman Lineament. This structural feature
signifies a significant change in geological history, separating the older Proterozoic rocks
of the Aravalli from the younger Paleoproterozoic sediments of Delhi.
At this spot, the rocks are ultramafic and ultrabasic with garnet mica schist and quartzite.
Ultramafic rocks are abducted slices of submarine deposits.
Around this area, the Indian Emerald is characterized by the presence of fluid inclusions.
These microscopic mineral- and liquid-filled cavities trapped within the gems offer
valuable insights into their formation environment and geological history.
S, Z & M shaped folds.
ISOCLINAL FOLD
Alternate layers of Quartzite and schists is present Here limbs is thicker than the
hinge which indicates it is Class 1C fold.

Class 1C fold
Here,Type 3 superposed folding occurs when two phases of folding intersect at nearly
perpendicular orientations. The first phase (F1) creates initial folds, and the second phase
(F2) refolds these, resulting in hook-shaped or crescent-like interference patterns.

Sigmoidal Veins
 Crescent moon structure

TYPE-2 FOLD (MUSHROOM SHAPED FOLD)

 DAY- 6 DECEMBER 19, 2024 | Thursday
LOCATION: GSI training centre,Zawar, Rajasthan

 Latitude: 24°20′42.140″ N
 Longitude: 73°41′46.889″ E

The GSI Training Centre (FTC) Jaipur, also known as the Field Training Centre, Zawar, is a
premier training institute for geoscientists in India. It is located in the scenic Aravalli hills,
about 30 km from Jaipur, Rajasthan.
The centre was established in 1977 with the aim of providing practical field training to
geologists, geophysicists, and other geoscientists. It offers a variety of courses on topics
such as geological mapping, mineral exploration, groundwater exploration, and
environmental geology.

Rock Garden:
The rock garden at this training centre contains different rock samples and structures.
At the start of the garden, two boards are displayed containing information about the
Stratigraphic succession of the Aravalli supergroup, the Topographical map of the field
training centre Zawar, and the Geological map of Rajasthan and northeastern Gujarat.
Some of the notable rock sample structures and their respective
regions are as follows:
Rock Type Locality Structures
Rhyolite Porphyry Mount Abu Tight Fold Open fold
Talc Devpura, Udaipur Plunging Fold Upright Fold
Stromatolitic Bhangwanpura
Limestone Million
Pyrophyllite East of Debari
Chalcopyrite – Pyrite Nanagwas, Sikar
Distt
Skarn Bel-Ka-Pahar,
Sirohi
Copper Ore (cp- Nanagwas, Sikar
covellite) Distt
Secondary Phosphate Jhamarkotra
Stockwork of Mochia mine,
Sphalerite Zawar
Galena
Agucha
Serpentinite Rikhabdev
Sphalerite & Pyrite Balaria mine
Sphalerite Mochia mine
Wollastonite Bel Ka Pahar,
Sirohi
Mica Bhunas, Bhilwara
Galena & Sphalerite Sindesar
Rajsamand
Gossan Rajpura Dariba
 LOCATION: Tihri River,Near Ramnath temple

 Latitude: 24°21′04.003″ N
 Longitude: 73°41′48.610″ E

The exposed rock unit consists of intercalated phyllite and dolomite, indicating a
sedimentary origin followed by metamorphic overprinting. The sedimentary layering
defines the S0 foliation, while the metamorphic foliation in the phyllite is identified as S1.
The area is metamorphosed up to greenschist facies.
Here we observed :-
Fold hinges and mullions: Fold hinges and mullions are present, providing valuable
information about the fold geometry and strain direction during deformation.
Tension gashes: Tension gashes with a sinistral sense of shear were observed at some
distance, indicating brittledeformation and shear movement.
Porphyroblasts: Porphyroblasts with a sinistral sense of shear were observed at some
distance, indicating brittledeformation and shear movement.
LOCATION:Geo-heritage Site (Zawar: The oldest Zinc
smelting site)
This site preserves the zinc retort distillation furnaces and remnants of related
operations around Zawar village, which are irrefutable evidence for the production
of metallic zinc on a commercial scale. The ancient mining city Zawar is the oldest
site in the world for smelting zinc from sphalerite. The zinc extracted from Zawar
was exported for making brass in Europe, a pioneer of the Industrial Revolution.
The carbon ("C) dating of remnants of wooden logs and charcoal used in mining and
metallurgical processes in Zawar gave variable ages ranging from 800 BC to about
the early nineteenth century.
 LOCATION: Near Mochia Hills, Zawar

 Latitude: 24°22′12″ N
 Longitude: 73°45′35″ E

We observed the phyllite and schist and also quartz vein which is milky describes
the pressure condition.
We identified the hinge and limb zone on the site with the help of S1 and S2.
When S1 and S2 intersect at an angle it describes the limb of the fold.
When S1 and S2 intersect at right angle describes the hinge of the folds.
Here S0 parallel S1, where S0 is the original bedding plane.
 DAY- 7 DECEMBER 20, 2024 |Friday
LOCATION: Lasadia Village,Rajasthan

Diamond drilling is a technique used to extract cylindrical core samples from the Earth's
subsurface for geological analysis. This method is widely used in mineral exploration,
geotechnical studies, and groundwater investigations. The process involves using a drill
bit embedded with industrial-grade diamonds to cut through rock formations, allowing
geologists to collect intact samples from different depths.

1. Drill Bit with Diamonds:

The drill bit used in diamond drilling is often made of a metal alloy and is embedded with
small industrial diamonds. These diamonds are extremely hard and capable of cutting
through hard rock formations that would be difficult or impossible to penetrate with
regular drill bits.

2. Coring Process:
The drilling apparatus consists of a hollow tube (the core barrel) that rotates along with
the diamond drill bit. As the drill bit cuts through rock, it removes a cylindrical core of
rock from the hole.
The core is captured inside the barrel and brought to the surface for analysis.
The diameter of the core can vary, but it is typically between 2.5 cm and 10 cm,
depending on the type of drilling equipment used.
core sampling refers to the process of collecting cylindrical rock samples from the
subsurface, which are extracted using a diamond drill bit. These core samples are
invaluable for geological analysis, as they provide a direct look at the rock formations
and materials beneath the surface. Here's how core sampling works in diamond drilling
Core Recovery:
 As the drill bit penetrates the rock, the cylindrical core of rock (the sample) is
extracted and retained inside the core barrel. The core barrel is periodically pulled
up to the surface (referred to as "retrieving the core") so the rock sample can be
removed and analyzed.
 The process is typically done in sections (e.g., every few meters), and the drill rig
operator will retrieve the core at regular intervals. Core retrieval is done by
removing the drill bit and core barrel from the borehole and extracting the sample.

Sequential Arrangement:
The cores are placed in the core boxes in sequential order based on the depth from
which they were retrieved.
Depth markers are crucial for proper arrangement. Each section of the core is labeled
with its depth interval.
 DAY- 8 DECEMBER 21, 2024 | Saturday
LOCATION: Haldi Ghati,Rajasthan
 Latitude: 24°53′41.1″ N
 Longitude: 73°42′19″ E

Haldighati, nested within the Aravalli Range, holds profound historical and
geological significance. Its name originates from the turmeric-hued soil ("haldi"
in Hindi), hinting at the iron-rich minerals. It also served as the battleground for
the iconic clash between Maharana Pratap's and Mughal's forces in 1576.
Gossans: -The presence of gossans, oxidised iron-rich outcrops, indicates past
sulfide mineralisation. These gossans suggest potential for underlying sulfide
deposits like pyrite or chalcopyrite.
Soil Colours and Alteration Processes: -The observed yellowish soil is
attributable to limonization, a weathering process where iron minerals like
pyrite oxidise and break down, leaving behind the characteristic yellow iron
hydroxide (limonite).
The red could be due to lateralisation, another weathering process prevalent
in tropical regions. This process concentrates iron oxides, giving the soil a
reddish hue.
 LOCATION: Sirohi,Rajasthan
 Latitude: 24°49′51″ N
 Longitude: 73°00′10”E

A well-exposed outcrop of Erinpura granite characterized by its coarse-grained

texture is observed at this location. The intrusion of the Eranpura granite marks
a significant geological event, as it penetrated the older Delhi Supergroup. The
estimated age of 1400-1500 million years places the Eranpura granite within
the Proterozoic Eon, offering a glimpse into the Precambrian geological record.
Weathering: -

The outcrop exhibited both spheroidal and Tafoni

weathering. Spheroidal weathering, characterised by the
formation of concentric, onion-like shells, suggests
prolonged exposure to weathering processes under semi-
arid conditions. Conversely, Tafoni are sheltered cavities
or hollows resulting from preferential erosion of weaker
zones within the rock
 LOCATION:15km from Sirohi,Rajasthan
 Latitude: 24°52′22.505″ N
 Longitude: 73°53′09.784″ E

This location presented an additional exposure of Eranpura granite, displaying

remarkable textural variation compared to the previously visited location. Here,
the granite exhibited an even more pronounced coarse-grained texture.
When observed from a distance, the outcrop exhibits a distinctive “Cauliflower–
like” structure developed by feldspar grains.

CS C′ fabric: The outcrop contains CS C′ fabric, which is a prominent kinematic

indicator of shearing.
 LOCATION:Mount ABU,Rajasthan
 Latitude: 24°35′33”N
 Longitude: 72°44′8″ E

Mount Abu is a hill station in the Sirohi district of Rajasthan, India. It is the only
hill station in the state and is on a rocky plateau in the Aravalli Range. The
Neoproterozoic mount Abu batholith comprises medium to coarse-grained, grey
and pink porphyritic to non-porphyritic biotite granites. Chemically and
mineralogically, these are sub-aluminous and potash-rich granites.

Mount Abu is known for its natural beauty, history, and mythology. It is an
excellent place to visit, offering views of the arid plains below. Some popular
attractions include:

 Nakki Lake: A popular spot for boating.

 Dilwara Temples: Ornate white marble temples that are centuries old.
 Sunset Point: A beautiful place to visit.
 REFRENCES

M Shamim Khan, Kamal kant sharma & Mahshar Raza (2005).Bombolai

continental pillow lavas (Neoproterozoic) from trans-aravalli region, Pali District,
Rajasthan and their tectonic significance

Ahmad, Iftikhar & Mondal, Mohammad. (2016). Do the BGC-I and BGC-II domains
of the Aravalli Craton, Northwestern India Represent Accreted Terranes?. Earth
Science India. 9. 167-175. http://dx.doi.org/10.31870/ESI.09.4.2016.11

Fareeduddin,Banerjee DM. Aravalli Craton and its Mobile Belts: An Update.

Episodes 2020;43:88-108. https://doi.org/10.18814/epiiugs/2020/020005

Bhowmik, Santanu & Dasgupta, Somnath. (2012). Tectonothermal evolution of

the Banded Gneissic Complex in central Rajasthan, NW India: Present status and
correlation. Journal of Asian Earth Sciences - J ASIAN EARTH SCI. 49.
http://dx.doi.org/10.1016/j.jseaes.2011.07.025

Official website of GSI: - https://www.gsi.gov.in/webcenter/portal/OCBIS

THE TEAM