Papers by Hemant Kumar
Indian Journal of Geosciences, Volume 78, No 2 , 2024
The Vindhyan Supergroup is the thickest sedimentary succession of India and its importance lies i... more The Vindhyan Supergroup is the thickest sedimentary succession of India and its importance lies in its vastness in time and space with an emphasis on atmosphere, climate, sedimentary cover and life. The Sohagi Ghat section in the Rewa district of Madhya Pradesh exposes the topmost part of the Kaimur Group, represented by the white to buff-colored Dhandraul Quartzite (sandstone) Formation. The overlying Rewa Group is differentiated into Panna shale, Lower Rewa Sandstone, Jhiri Shale, and Upper Rewa Sandstone formations. In the study area, Rewa succession, is composed of shale and sandstone interbeds with the wave and sole features, representing a storm-dominated shelf succession. The lithological characters, facies associated with them and sedimentary structures indicate that Panna Formation has foreshore to shoreface depositional environment. Lower Rewa Sandstone (≡Asan Formation) suggests a tidal flat environment of deposition. Jhiri Formation suggests an outer shelf environment of deposition while that of the Upper Rewa Sandstone Formation indicates tide and wave-dominated shore-face environment of deposition. The cyclicity of the thick sequence of arenaceous sediments interbedded with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the regressive strand of sea changes.
ANUSANDHAN Vigyaan Shodh Patrika, 2023
- Geomagnetic and gravity surveys at the surface have been coupled to explore the possibility of ... more - Geomagnetic and gravity surveys at the surface have been coupled to explore the possibility of concealed kimberlite/lamproite pipes under the sedimentary cover of the Kaimur Group of rocks of the Vindhyan Supergroup. A bipolar high magnetic primary source, based on the airborne magnetic survey, was confirmed by surface-magnetic and gravity survey of the area beneath sandstone at an estimated depth of about 150 m.Finally, based on the geological and geophysical interpretation of the area and the results obtained from the analysis, to confirm the possibility and determine the geometry and size of concealed diamondiferous kimberlite/lamproite pipes under the platformal marine sediments of the Vindhyans, a detailed investigation is warranted from the
rock samples obtained from the exploratory boreholes.
ANUSANDHAN Vigyaan Shodh Patrika, 2023
- In India, Vindhyan supergroup of rocks is one of the thickest polycyclic sedimentary sequence o... more - In India, Vindhyan supergroup of rocks is one of the thickest polycyclic sedimentary sequence of limestone, sandstone, siltstone and shale, which was deposited during the Neo-Proterozoic age. The Rewa group exposed at Sohagi Ghat and Duari areas having a polycyclic succession of sandstone, siltstone and shale are suitable locales for such microbial-induced sedimentary structures-MISS, an indicator of microbial colonization at the time of deposition. These are the records of their growth, destruction, decay, and diagenesis, which inter alia include sand cracks, mat chips, remnant gas domes, pyrite patches and iron laminae. The presence of preserved microbial mats in the Rewa group sediments reflects the simultaneous depletion of carbon-dioxide and increase in oxygen due to life processes. After photosynthesis began, it led to changes in the environment of archaic life forms. Plankton, blue-green algae and photo-synthetic bacteria decompose atmospheric carbon dioxide and reduce it to produce atmospheric oxygen. These associated structures are strong indicators of the slow sedimentation in transgressive, tide-influenced, shallow marine, supratidal conditions are being comprehensively evaluated and interpreted in this study.
ANUSANDHAN Vigyaan Shodh Patrika , 2022
Spillage in embankment of Barua Sagar of District Jhansi has been of concern since two decades.
G... more Spillage in embankment of Barua Sagar of District Jhansi has been of concern since two decades.
Geologically it is formed by hard graniterock layers of Gneissic complex of Protozoic era. Exfoliation joints of
2cm to 10 cm are usually observed with spillage. Many remedial measures like filters, clay blankets and
Geosynthetic jutes can be applied to control it. Use of Bentonite with plasticizer is recommended for cheap and
best remedial measures.
Indian Journal of Geosciences 77 (1), 107-117, 2023
The undeformed clastic sequences of Vindhyan hold the mystery of the processes responsible for th... more The undeformed clastic sequences of Vindhyan hold the mystery of the processes responsible for the explosion of life. The Rewa Group exposed at Sohagi Ghat and Duari areas having a polycyclic succession of sandstone, siltstone and shale are suitable locales for such microbial-induced sedimentary structures-MISS, an indicator of microbial coloniza¬tion at the time of deposition. These are the records of their growth, destruction, decay, and diagenesis, which inter alia include sand cracks, mat chips, remnant gas domes, pyrite patches, and iron laminae. These associated structures are strong indicators of the slow sedimentation in transgressive, tide-influenced, shallow marine, supratidal conditions that are being comprehensively evaluated and interpreted for the first time.
Conference Presentations by Hemant Kumar
National Seminar on Geology and Mineralisation of Mahakoshal Group- Future Perspective & Recent Amendments in MEMC & Auction Rules, 2022
The ENE-WSW trending Mahakoshal Supracrustal Belt (MSB) is an asymmetrical rift basin in the
nort... more The ENE-WSW trending Mahakoshal Supracrustal Belt (MSB) is an asymmetrical rift basin in the
northern part of CITZ. The meta-sediments of MSB are
subjected to polyphase tectono-thermal events involving
several cycles of volcano-sedimentary deposition,
deformation, metamorphism and magmatism. The
crustal-scale Son-Narmada North Fault (SNNF) delimits
this belt in the north and Son-Narmada South Fault
(SNSF) in the south, together known as Son-Narmada
(SONA) Fault System. The Late PalaeoproterozoicNeoproterozoic Vindhyan Supergroup of rocks are
exposed towards the north of this belt. In contrast,
towards the south, a vast expanse of gneisses and
migmatites which mark the basement for Mahakoshal
sediments, are exposed along SNSF. The major rock
types of the Mahakoshal Group include metasedimentaries (quartzite-pellite-carbonate-greywacke BIF), subordinate metabasalt and minor ultra-mafics and
intrusive granitoids and sporadic mafic dyke swarms.
The pronounce granitic magmatic activities around
SNSF has makred around 1600 to1800 Ma. These are
exposed as plutons near Dudhi, Jabalpur and Jhirgadandi
shows their regional extend along SNSF. Field
characteristic shows presence of mafic micro-granular
enclaves (MMEs) and developement of acicular apatite.
Geochemically, they are meta- and peraluminous, subalkaline to calc-alkaline, hybrid type (S-type granite) and
emplaced during post-orogenic stage. It also have high
whole-rock Al O /TiO ratios and A/CNK plots, confirm
its origin through partial melting of meta-sedimentary
rocks.
The metapelitic sequence of the Parsoi Formation
of the Mahakoshal Group, represented dominantly by
phyllite, is exposed in the area and has mineral assemblages akin to greenschist facies. Phyllite displays
a well-developed schistosity and occurs in two varieties;
(a) fine-grained greenish grey andalusite bearing
muscovite phyllite; and (b) reddish-brown, medium-to
coarse-grained biotite phyllite/schist with andalusite. Its
protolith corresponds to fine-grained pelitic sediments
affected by metamorphism reaching the chlorite zone of
green-schist facies and showing lepidoblastic to granolepidoblastic textures defined by the alignment
micaceous minerals. In comparison, the latter has a
typical mineral assemblage of biotite + quartz +
muscovite + chlorite. These rocks belong to the biotite
zone of greenschist facies, indicating a slightly higher
grade than the chlorite zone fringing the contact aureole
of a granitic pluton in the area.
Two distinct zones representing contact metamorphic facies within the aureole have been
identified. The outer zone of contact aureole display
assemblage comprising the phases quartz+ albite+
muscovite+ chlorite+ biotite+ andalusite in the albiteepidote-hornfels facies. Subsequently, the inner zone,
adjacent to the pluton, contains an assemblage of quartz+
plagioclase+ muscovite+ biotite + andalusite. The values
of Fe O (7.04 - 8.19%) andMgO (1.69- 2.07%) observed
in hornfelses are on the higher side as compared to the
andalusite bearing phyllite (Fe O 5.74 – 7.7% and MgO
0.79- 1.59%) of the area. This implies that the enrichment
of Fe is in along the Mg-rich minerals (Biotite) zone. The
low-grade regionally metamorphosed greenschist facies
(M ) of the Parsoi Formation shows overprinting of
Hornblende-Hornfels facies of contact metamorphic
assemblages (M )inthe adjoining areas ofthe pluton.
Online Conference River Mouth Systems and Marginal Seas - Natural drivers and human impacts , 2022
The Vindhyan Supergroup is the thickest sedimentary succession of India and its importance lies i... more The Vindhyan Supergroup is the thickest sedimentary succession of India and its importance lies in its
vastness in time and space with an emphasis on atmosphere, climate, sedimentary cover, and life. The
Sohagi Ghat section in the Rewa district of Madhya Pradesh exposes the topmost part of the Kaimur
Group represented by the white to buff-colored Dhandraul Quartzite (sandstone) Formation. The
overlying Rewa Group is differentiated into Panna shale, Lower Rewa sandstone, Jhiri shale, and Upper
Rewa sandstone formations. The cyclicity of the thick sequence of arenaceous sediments interbedded
with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the
regressive strand of sea changes.
In the Sohagi Ghat section, the Panna Formation shows three major lithofacies, identified as, Thinly
bedded siltstone facies (TBSF), Silty-shaly facies (SSF), and Interbedded sandstone-siltstone facies
(ISSF). It is characterized by an interbedded sequence of very thin to thinly laminated shale and very
fine-grained sandstone with thick beds of siltstone/shale. At places, the shales are calcareous in nature.
The Lower Rewa sandstone (=Asan sandstone) is sandwiched between the Panna shale below and the
Jhiri shale above in the area. The shaly, shelfal succession of the Rewa shale as a deep-water succession
punctuated by wedge-shaped sandstone and/or conglomerate bodies occurring at multiple
stratigraphic levels. These wedge-shaped sandstone and/or conglomerate units as regressive wedges
with varying depositional environments. The lithofacies associations of the heterolithic Lower Rewa
Sandstone can be classified as i) Sandstone lithofacies association ii) Siltstone lithofacies association
and iii) Shale lithofacies association. Sandstone lithofacies association consists of fine to very-finegrained sandstone with an average thickness of about 55 cm (maximum 3 m thick). The sedimentary
structure viz. planar cross-bedding, trough cross-bedding with mud drapes low angle discordances,
interference ripples, current ripple, cuspate ripple, flute cast, furrow & ridge etc. present in the
sandstone lithofacies association is indicative of sand flat environment of deposition within upper
subtidal to intertidal domain. The syn-sedimentary deformation structures observed at places within
the sandstone are due to the quick deposition of water-saturated sediments that expel water causing
liquefaction and deformation. Flute casts occur abundantly in shallow water marine as well as in the
ICGG 2023 : International Conference on Geology and Geophysics, International Journal of Geological and Environmental Engineering, 2023
The Central India Diamond Province (CIDP) is known for the occurrences of primary and secondary s... more The Central India Diamond Province (CIDP) is known for the occurrences of primary and secondary sources for diamonds from the Vindhyan platformal sediments, which host several kimberlites, with one operating mine, Majhgawan, and a second kimberlite with mineable reserves from the Saptarshi (Bunder) field. The known kimberlites are Neo-Proterozoic in age and intrude into the Kaimur Formation of the Vindhyan Supergroup. Kimberlites overlain by the Rewa Formation are likely to be better preserved than those outcropping in different rock units. Based up on the interpretation of areo-magnetic data, in parts of Chitrakoot and Banda districts, Uttar Pradesh and Satna district, Madhya Pradesh, India, three potential zones were demarcated. The ground magnetic coupled with gravity survey was conducted to validate the
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
Geoheritage studies are becoming an emerging branch of geosciences, with its methods and
nomencla... more Geoheritage studies are becoming an emerging branch of geosciences, with its methods and
nomenclature. These studies require the combination of purely scientific, practical and geological as
well as non-geological tasks by the geoscientists. The exploration, reporting and preparation of an
inventory of geologically unique localities and their protection and preservation is a need of the hour
in India. Geological mapping along the Sohagighat road section, Rewa district, Madhya Pradesh has
allowed us to realize the uniqueness of exposures of marine sedimentary structures in the Upper
Vindhyan Group of rocks in its eastern extremities. These outcrops along the national highway
NH-7 provide an opportunity to establish this approximately 2km road section as a geoheritage site
(geosites).
Along the Sohagighat section, the Kaimur Group is represented by white to buff-coloured
Dhandraul Quartzite (sandstone) Formation. The overlying Rewa Group is differentiated into
four formations i.e., Panna Shale, Lower Rewa Sandstone, Jhiri Shale and Upper Rewa Sandstone
formations. The Panna Shale Formation is characterized by an interbedded sequence of very thinly to
thinly laminated shale and very fine-grained sandstone with thick beds of siltstone/shale. At places,
the shale is calcareous. The Lower Rewa Sandstone is a hetero-lithic formation with sandstone-
siltstone-shale repetitive package. The Jhiri Formation is characterized by maroon, purple to
green coloured, very fine-grained (silt to clay size) rock. The Upper Rewa Sandstone Formation is
characterized by purplish to white, very fine to medium-grained arenitic sandstone, and occurs as
a cliff.
This section exemplifies an array of sedimentary structures seldom observed in one place with
good exposures expressing elaborate details. The primary sedimentary structure observed within the
different formations of Rewa Group is parallel lamination, planar cross beds, tidal bundles, trough
cross-beds, hummocks and swales, wavy beds, ripples, flute cast, syneresis cracks, wrinkle marks,
mud cracks, sole mark, tool marks, gutter casts, septarian nodules besides preserved algal mats in
the form of microbial induces sedimentary structure (MISS) and pen-contemporaneous structures.
The availability of well-preserved sedimentary structures is due to the largely undeformed and
unmetamorphosed nature of the terrain and the variety of primary marine sedimentary structures
exposed along the road sections makes it suitable to develop as a geoheritage site.
As the marine sedimentary structures are the result of the different sedimentary processes
involved during the time of deposition, this section demonstrates variety of sedimentary features
which are significant for geological research. Thus, it can also be exploited efficiently for training
professionals, researchers and students specializing in marine sedimentary processes besides
regular visitors. The road maintenance and rock-falls, vegetation expansion, and irresponsibility
of occasional visitors (rock graffiti and garbage dumping) are potential dangers for this potential
geoheritage site. A suitably designed conservation plan, in consultation with the local authorities
and highway authorities, needs to be developed.
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
The Vindhyan sedimentary basin partially wraps around the ∼2500 Ma old Bundelkhand
Craton in Cent... more The Vindhyan sedimentary basin partially wraps around the ∼2500 Ma old Bundelkhand
Craton in Central India. The celebrated hill fort of Kalinjar (Kalanjar) is one of the areas where
it shows the typical Eparchean unconformity that marks the transition between the Archean and
Proterozoic eons in Earth's history. The Kalinjar Fort is situated in the village of Tarahati under
the Naraini tehsil, Banda district, in the Bundelkhand region in Uttar Pradesh on the border with
Madhya Pradesh. It stands on an isolated flat-topped hill comprised of Kaimur sandstone resting
unconformably over the Bundelkhand granitoid Complex (BGC), which rises 244m above the plain.
The Chandela Fort is aligned in an east-west direction, being nearly 2km in length and 800m in
breadth. It is built on strong 25-30m wide foundations and has a height of around 30-25m with 8m
wide summit. The material used in its construction is the large sandstone and granite pieces derived
from the nearby localities.
The Kalinjar Fort is one of the largest and unbeatable forts of medieval India, which incorporates
many styles of architecture in this fort viz. the Gupta style, Pratihara style, Panchayatan Nagar style
etc. The name of Kalanjaradri, or the hill of Kalinjara, is said to have been derived from Siva himself,
who, as Kala, or "Time", causes all things to decay (jar), and who is, therefore, the destroyer of all
things, and the god of death. There are two entrances to the fort of Kalinjar, of which the principal
is on the north side and the other at the southeast end leading towards Panna. Besides architectural
antiquity, there are several mythological places and sculptures within the fort premises. One of
the small caves, called as Sitasej, contains a stone bed and pillow. The Patal Ganga is a large deep
well, or reservoir, cut in the rock, while the Pandu-kund is a shallow circular basin, about 12 feet in
diameter, into which the water is constantly trickling from the crevices. There is a colossal figure of
Kal Bhairav, which has 18 arms with the usual garland of skulls, snake earrings, snake armlets and
a serpent twined around the neck. Several broken pieces of sacred sculpture tell about the cultural
richness and diversity as most are centuries old.
Geologically, the Vindhyan sedimentary basin is one of the largest repositories of undeformed
sediments deposited over a long time. Approximately 800m before the main entrance of the fort,
the geological boundary is between sedimentary rocks of the Vindhyan Supergroup, 1400 million
years old, and Archaean rocks comprising granites that are more than 2000 million years old. This
boundary represents an area that witnessed a significant change in the Earth's tectonics and climate
systems. It is characterized by a period of erosion and non-deposition that led to the formation of
nonconformity, where the older Archean rocks are overlain by relatively younger Proterozoic rocks
deposited in one of the Purana basins. This unconformity separates the Proterozoic Kaimur sandstone
(1200 Ma) and Bundelkhand granite (more than 2000 Ma) with relatively younger intrusive dolerite
dykes, representing a time gap of approx. 600 Ma, which is a period of remarkable gap in geological
history. This unconformity indicates the enormous time gap in the creation of the earth's crust.
The approach road from the village Tarahati to Kalinjar Fort provides an opportunity to attract
potential visitors for its geological importance before looking into the history and architecture of
the fort. The road maintenance, vegetation expansion, and irresponsibility of occasional visitors
(rock graffiti and littering) are potential dangers to this geo-heritage site. As the fort is conserved and maintained by the Archaeological Survey of India (ASI), a suitably designed conservation plan
expressing its geological importance of this geoheritage site, also needs to be developed to address
these issues.
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
Geochemical mapping was carried out in toposheet 63G/8 covering parts of Prayagraj and Chitrakoot... more Geochemical mapping was carried out in toposheet 63G/8 covering parts of Prayagraj and Chitrakoot districts of Uttar Pradesh and Rewa district of Madhya Pradesh. The main objective of the work was to generate the geochemical baseline data which will aid in managing and developing the natural resources and its applications in environmental, agricultural, public health and other societal concerns.
Geomorphologically the area is divided into highly dissected hills, moderately dissected
hills, low dissected hills, pediment, pediplain and gentle undulating plain. The central and north-
eastern part of the areas is dominated by hills and the northern and southern portion of the area is
represented by plains. The dendritic pattern is the dominant drainage pattern observed in the area,
however radial drainage pattern in the central part and parallel drainage pattern at few locations
are also observed. Geologically, the study area shows exposures of lithounits belonging to Bhauri
and Manikpur formations of Kaimur Group and Jhiri Shale Formation of Rewa Group of Vindhyan
Supergroup. In the study area, the Bhauri Formation is represented by sandstone. Megascopically,
sandstone is thinly bedded, laminated, pitted and fined to medium-grained. Manikpur Formation is
represented by white coloured, fined grained sandstone and whitish grey/greyish white coloured,
fine to medium-grained orthoquartzite which at places is ferruginous in nature. The overlying Rewa
Group is represented by thinly laminated shale belonging to Jhiri Formation. The low-lying areas
are covered by the Banda Alluvium of quaternary ages.
The statistical analysis of a total of 182 nos of composite samples revealed that the values of
Lead (Pb) in 158 samples are above 36.62ppm. The minimum value of Pb in the analytical data
is 18ppm whereas the maximum value is 260ppm. The mean value of Pb in the analytical data is
31ppm. The median is 26.8ppm, the mode is 25ppm and the standard deviation is 22ppm while
the threshold value is 34.4ppm. The population is positively skewed (7.88) and leptokurtic (75.08).
The dispersion pattern occurs in the central and southern parts of the area around Hardoha, Madri,
Khaira, Champagarh, and Baraiti Bari villages of Rewa district of Madhya Pradesh. The underlying
lithologies are sandstone of Kaimur Group of the Vindhyan Supergroup.
The concentration of Chromium (Cr) in the area varies from 72 to 169ppm with a mean of
121.04ppm and a median of 120ppm. The threshold value in the area is 141ppm. The population is
positively skewed (0.098) and leptokurtic (0.456). The geochemical dispersion pattern of Cr indicates
a relatively higher concentration across all the formations as well as over the Banda Alluvium, in the
northern part of the area.
The concentration of Zirconium (Zr) in the area varies from 294 to 703ppm with a mean of
480.560ppm and a median of 483.5ppm. The population is positively skewed (0.068) and platykurtic
(-0.800). The threshold value in the area is 624.5ppm. The geochemical dispersion pattern of Zr
indicates a relatively higher concentration in the central part of the area over Manikpur Formation.
The concentration of Arsenic (As) in the area varies from 1.5 to 16.890ppm with a mean of
6.505ppm and a median of 5.9ppm. The population is positively skewed (1.372) and leptokurtic
(1.820). The threshold value in the area is 8.5ppm. The geochemical dispersion pattern of As
indicates a relatively higher concentration in the central and eastern parts of the area over Manikpur
Formation and Banda Alluvium respectively.
The concentration of Hafnium (Hf) in the area varies from 8.230 to 21.130ppm with a mean
of 14.557ppm. The population is positively skewed (0.166) and platykurtic (-0.365). The threshold
value in the area is 18.156ppm. The geochemical dispersion pattern of Hf indicates a relatively higher
concentration in the southwestern, central and northeastern parts of the area over the Manikpur
Formation, Bhauri Formation and Banda Alluvium respectively.
The enrichment of the concentration of Pb-11 ppm, Cr-106 ppm and Zr-121ppm follows the
topography and drainage system indicating the sandstone of Manikpur Formation of Kaimur
Group and its equivalent Dhandraul Formation is considerably probable source of enrichment of
Pb, Cr, Zr, in the area. The provenance of these formations is again from the weathering products of
Bundelkhand Granitoid Complex (BGC) and older metamorphic occurring as xenoliths.
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
The rocks of the Kaimur Group unconformably overlie the calcareous-argillite sequence of Semri
Gr... more The rocks of the Kaimur Group unconformably overlie the calcareous-argillite sequence of Semri
Group and are widely dispersed in Vindhyan basin. It consists of thick arenite-argillite sequence
with a thickness of approx 365m. The Dhandraul Sandstone Formation of Kaimur Group forms the
top most unit of this group. The sandstone comprises of very fine to medium grained whitish, dirty
white, pinkish and purple coloured sub-litharenite to quartz arenite which is cemented mainly by
secondary silica to form hard and compact rock. The beds are thinly to very thickly bedded ranges
from 10cm to more than 1.0m and shows both coarsening as well as bed thickening succession towards
top. The sedimentary structures observed in the Dhandraul Sandstone are mainly small to large scale
trough and planar cross beds, tidal bundles, ripple marks and PCD structures. Petrographically, the
sandstone is fine to coarse grained in nature and made up of monocrystalline quartz ranging in
between 85-95%. The matrix is less than 15%. Feldspar and lithic fragments together constitute in
between 4-15% in the groundmass. Mica constitutes only 1%. Clasts are sub-angular to sub-rounded with moderate to well sorting. The sandstone is textually and mineralogically mature. Zircon, rutile,
biotite, magnetite and tourmaline are common heavy minerals in the groundmass.
Geochemical plots using major oxides ratios suggests that Dhandraul Sandstone has a wide
range of geochemical composition ranges from sub-litharenite to quartz arenite. Ternary plot (Blatt
et al., 1980) suggests that sandstones are mainly ferromagnesium potassic to potassic in composition.
Ternary plot of Th, Zr and Sc (Bhatia & Crook, 1986) indicates that sandstone was deposited under
active to passive continental margin. Tectonic discrimination diagrams suggest that sandstone was
formed under craton interior to recycled orogens setting. Binary plot of TiO2 vs Zr (Hayashi et al.,
1997) shows that, the source for these sandstone sediments were igneous rocks of intermediate to
felsic composition. Chemical index of alteration (CIA) and index of compositional variation (ICV)
indicates moderate to high degree of alteration and also suggests well maturity. Similarly, plagioclase
alteration index (PAI) also suggests intense destruction of feldspars from source during weathering,
transport, sedimentation, and diagenesis in humid condition.
Thus, it can be concluded that, the variation in chemical composition of the sandstone of
Dhandraul Formation is mainly controlled by the combined effect of alteration indices of chemical
weathering faced during prolonged cycles of transportation and sedimentation.
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
The vast spread of the lateritic horizons above the rocks of the Kaimur Group is the possible
sto... more The vast spread of the lateritic horizons above the rocks of the Kaimur Group is the possible
storehouse of critical mineral concentrations like V, Ti, Sc, Ga and Zr, etc. Being ubiquitously
developed on the top surface of both Dhandraul and Scarp Sandstone in and around Chitrakoot area
of Uttar Pradesh, these lateritic horizons have gone through the pedogenic process, formation of
pisolitic structures, the concentration of iron, aluminium along with other essential trace elements,
which further makes the study of this lateritic horizon more critical. Hence, the petrographic
studies, trace element concentrations (ICPMS data), and SEM analysis revealed these lateritic
horizons' mineral potential. The lateritic rocks mainly comprise limonite, gibbsite, magnetite and
hematite. Petrographic observations of laterite over the Dhandraul quartz arenite reveal that all the
silicate minerals have been transformed into a mixture of Fe and Al oxide and hydroxides. Hence,
the samples mainly contain goethite and limonite as essential minerals and quartz as accessory
minerals. Goethite is showing typical colloform banding. Colloform banding can be very well
appreciated both under transmitted and reflected light. Limonite is characterized by its yellow
internal reflection. The petrographic studies further show that the goethite minerals underwent
alteration and formed bauxite minerals such as gibbsite and boehmite. The presence of gibbsite is
more where the lateralization is gradually more. The pisolitic texture and progressive lateralization
are also observed in the samples. The development of pissolitic textures suggests that they are
further in the process of bauxite formation. This pissolite probably represents bohemite. All these
progressive and intense lateralization and bauxitization processes have led to the leaching of mobile
silicate phases and the concentration of less mobile trace elements along with Fe and Al. The trace
element concentration in the bauxite layers for a few samples shows interesting results, i.e., V (avg.
1120ppm), Zr (avg. 325.85ppm), Ba (avg. 253ppm) and Sc (avg. 93.45ppm). The SEM studies of the
lateritic horizons further (point, line, and bulk analysis) show values for Sc varying between 900 to
1600ppm. The spatial spread of this lateritic horizon is vast; however, the thickness is maximum
up to 2.5m to 3m. These lateritic horizons are well spread over an extensive area, much beyond
the scope of the present study. However, the majority of land falls in agricultural and forest areas.
Hence it would be difficult to propose immediate programs for exploration in these areas, however,
future exploration possibilities cannot be ruled out.
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
The study aims to present a detailed facies analysis and depositional environment of the rocks
of... more The study aims to present a detailed facies analysis and depositional environment of the rocks
of the Kaimur Group of the Vindhyan Supergroup. Exposed outcrops and cliffs were examined
in detail by section measurement and sedimentary logs were created. The logs are categorized
bed by bed into several facies according to lithology and sedimentary structures. The focus was to
identify the facies succession and to analyze the depositional environment of Dhandraul and Scarp
Sandstone formations.
The Scarp Formation comprises six sub-facies namely sandstone with tidal bundles sub-facies,
planar cross-bedded facies, herringbone cross-bedded facies, ripples with mud crack, parallel
laminated sandstone and trough cross-bed facies. Trough cross bed facies sandstone is thin to
medium bedded, fine-grained immature quartzo-felspathic sandstone having erosional surfaces at
the top. Trough beds with ripple at the top are characteristic of unidirectional flow and indicate a
shallow marine condition, these sub facies are found in association with sandstone having tidal
bundle sub-facies, which is thin to medium bedded, fine-grained sandstone. These sub-facies are
characteristics feature of the tidal-influenced shallow marine environment which is formed by the
periodic activity of flood flow and ebb flow during spring and neap tide. The presence of scour
surfaces at the top of the sandstone having tidal bundles indicates features of high energy condition,
which causes the flute casts under flood flow during the deposition above the fair weather base.
Overall, the Scarp Formation suggests a subtidal to intertidal environment of deposition.
The Dhandraul Sandstone Formation comprises five sub-facies namely, planar cross-bedded
sub-facies, trough cross bed facies, sandstone having tidal bundle facies, and herringbone sandstone
sub-facies. The presence of sandstone having tidal bundle facies with herringbone sub-facies is
typical of the intertidal zone, where neap and spring tide dominates. These sub-facies association is
overlain by sub-facies of medium to coarse-grained planar cross-bed and trough cross-bedded sub-
facies. The grain size of the sediment coarsening sequence, as well as the bed thickening sequence,
suggests shallowing of the basin with a repetitive cycle of bed thickening and thinning. Overall, this
unit shows intertidal to supratidal zone of deposition.
Granulometric analysis of samples from the Dhandraul Sandstone Formation shows that
interbeds of the formation have size < (Φ) 3.75 (Very fine sand) to (Φ) -0.2 (Pebbly sand). The analysis
results show that a very less amount of sediments is also present which is less than < (Φ) 3.75. The
presence of the pebbly nature of grains at the top of the bed either indicates high energy conditions
during the sedimentation to drag out coarser sediments or there should be a break in sedimentation.
17
On the other hand, Scarp Sandstone Formation have sizes from < (Φ) 3.75 (Very fine sand) to (Φ)
0.75 (Coarse sand). The average value of skewness of the sediment shows positive nature indicating
moderate sorting.
The paleocurrent data collected from planar cross beds (28 azimuths) show a mean azimuth of
230o
-355 o whereas trough beds (180 azimuths) range between 250 o
-355 o
. The ripple shows azimuth
between 35o
-340o whereas 17 nos. of parting lineations shows the trend between 260o
-355 o
. It is
inferred that the granite, granodiorite, gneiss, and metasedimentary rocks of the Mahakoshal Group
and Chotanagpur granite–gneiss present in the eastern and southeastern direction may be the
possible source rocks for the Kaimur Group.
Spl Publication National seminar on "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP),, 2023
The Vindhyan Supergroup in Central India is the thickest sedimentary succession of India which is... more The Vindhyan Supergroup in Central India is the thickest sedimentary succession of India which is un-metamorphosed and feebly deformed. It is developed in an intracratonic, dominantly marine setting and its importance lies in its vastness in time and space. The area around Sohagi Ghat in the Rewa district of Madhya Pradesh exposes the complete succession of the Rewa sequence overlying the topmost part of the Kaimur Group, represented by the white to buff-coloured Dhandraul
Quartzite. The Rewa Group is differentiated into Panna Shale, Lower Rewa Sandstone, Jhiri Shale
and Upper Rewa Sandstone formations. The cyclicity of the thick sequence of arenaceous sediments
interbedded with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the regressive strand of sea changes. The preservation of stratal assemblages in the Rewa
Group of rocks is discernible as the influence of deformation and metamorphism is absent or rare.
The Panna Formation shows three major lithofacies, identified as, thinly bedded siltstone facies (TBSF), silty-shaly facies (SSF), and interbedded sandstone-siltstone facies (ISSF). It is characterized
by an interbedded sequence of very thin to thinly laminated shale and very fine-grained sandstone
with thick beds of siltstone/shale. At places, the shales are calcareous. The Lower Rewa Sandstone
(=Asan Sandstone) is shaly, shelfal succession punctuated by wedge-shaped sandstone bodies are
regressive wedges with varying depositional environments and occurring at multiple stratigraphic
levels. Based on the lithological characteristics the Lower Rewa Sandstone can be subdivided into
three lithofacies i) Sandstone lithofacies ii) Siltstone lithofacies and iii) Shale lithofacies. The sandstone
lithofacies comprises fine to very fine-grained sandstone and sedimentary structures present in it are
suggestive of deposition in intertidal domain.
The overlying Jhiri Shale Formation is classified as (i) Silty-Sandy facies (SStF) and (ii), Silty-
Shaly facies (SShF). The SStF litho-facies comprises an interbedded sequence of silty and sandy
component, where the silty component is more and sequence is very thinly laminated to thinly bedded
in nature, having thickness more than 10-12m with fining upward sequence and the sandstone-
siltstone hetrolithic units are the most common characteristic features signifying intermediate
fluctuation of flow. The silty-shaly facies (SShF) consist primarily of silty and, to a lesser degree,
shaly sequences. This sequence of Jhiri Shale Formation comprises of silty sand in the lower part
followed upward by the silty shaly facies. The silty sandy facies comprise of interbedded sequence
of siltstone and sandstone having swales and hummocky cross-stratification suggesting deposition
in between storm and fair weather wave base under the lower shoreface in transgression. Overall,
this sequence suggests a transitional environment between lower shore to offshore depositional
settings. The Upper Rewa Sandstone has been divided into five facies (i) Liquefied Sandstone (LSt)
(ii) Low Angle Parallel Bedded Sandstone (LAPBSt), (iii) Fine-grained Sandstone (FSt), (iv) Cross-
bedded Sandstone (CBSt), (Large-scale Planar Cross-bedded Sandstone, Herringbone Cross-bedded
Sandstone, Large-scale Trough Cross-bedded Sandstone), (v) Ripple Laminated Silt-mudstone
(RLSiM) which indicates the tide and wave-dominated shoreface environment of deposition.
The Rewa succession, exposed at the Sohagi ghat section, is composed of shale and sandstone
with primary and penecontemporaneous structures, which facilitated facies analysis of these
sediments. The lithological characters, facies associated with them and sedimentary structures
indicate that Panna Formation is of foreshore to shoreface depositional environment. Lower Rewa
Sandstone suggests a tidal flat environment of deposition. Jhiri Formation suggests an outer shelf
15
environment of a deposition while that of the Upper Rewa Sandstone Formation indicates a tide
and wave-dominated shore-face environment of deposition. It is difficult to confirm that cyclicity is caused by a mechanism with a constant time but the regular interval of bedding and cyclic sequences reflects allogenetically controlled periodicity.
GSI "Vindhyan Supergroup: Recent Advances, Challenges, and Opportunities (VISACOP), Abstract Volume, 2023
13
Abstract No: T1/P-16
Tectonic Signatures of Passive Margin Settings of the Vindhyan Sequence i... more 13
Abstract No: T1/P-16
Tectonic Signatures of Passive Margin Settings of the Vindhyan Sequence in Son
Valley, Central India
Hemant Kumar, Ajay Shanker Pandey, Sibabrat Nayak and Sanjiv Kumar
Geological Survey of India, Northern Region, Lucknow
The Vindhyan sedimentary basin of north western and central India is one of the largest
undeformed, Meso-Neoproterozoic basins in the world. During the Proterozoic, the continental crust
witnessed the extensive development of intra-cratonic basins when the thick sedimentary strata
were deposited in these un-metamorphosed basins. The intra-cratonic Vindhyan basin developed
in the central and north-western part of the Indian shield is the largest and thickest Proterozoic
sedimentary succession of India which records the longest depositional histories in terms of its
vastness in space and time. Thus, the study across this basin may help in understanding paleo-
reconstructions, sediment source determination, and the evolution of plate tectonics processes.
The present studies of Vindhyan Supergroup of sediments in the Son Valley sector in the
Central India, reveal that the distinct set of lineaments trending (ENE-WSW) along the Son-Narmada
lineament is responsible for carving out the present configuration of the Vindhyan basin. There
appears to be a series of movements along these geo-sutures which follows the same trend as well
as the N-S, sympathetic faults with attendant cross faults developed along the southern margin of
the basin.
The tectonic discrimination diagrams (SiO2 vs Log K2O/Na 2
O) suggests the passive continental
margin setting for the deposition of the sandstones of Dhandraul Formation, Kaimur Group as well
as Upper Rewa and Lower Rewa Sandstone formations, Rewa Group. The passive margins are
considered to be less deformed but post-continental break-up deformation and associated uplift
have been recorded in the area around Shankergarh area in Prayagraj district, Uttar Pradesh, and
Sohagighat areas in Rewa district, Madhya Pradesh.
Along the Sohagighat section, a reverse fault has been observed along the ENE-WSW direction
with an inclination of approximately 28° towards the south-west. As the thrust faults are commonly
associated with the deformation of layered sediments, especially in passive margins, it signifies
the post-break-up incipient shortening and thickening of the strata, under the action of horizontal
compression which originates due to ridge push. Here the movement of the hanging wall up and
over the footwall material creates the canonical stratigraphic succession, wherein the sedimentary
strata of the Panna Formation are repeated. The density exerts a major control on the vergence of
thrusting and the sedimentary layering provides a pre-existing mechanical anisotropy along which
faults propagate. This provides ideal initial conditions for ramp-flat geometries as evident here.
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rock samples obtained from the exploratory boreholes.
Geologically it is formed by hard graniterock layers of Gneissic complex of Protozoic era. Exfoliation joints of
2cm to 10 cm are usually observed with spillage. Many remedial measures like filters, clay blankets and
Geosynthetic jutes can be applied to control it. Use of Bentonite with plasticizer is recommended for cheap and
best remedial measures.
Conference Presentations by Hemant Kumar
northern part of CITZ. The meta-sediments of MSB are
subjected to polyphase tectono-thermal events involving
several cycles of volcano-sedimentary deposition,
deformation, metamorphism and magmatism. The
crustal-scale Son-Narmada North Fault (SNNF) delimits
this belt in the north and Son-Narmada South Fault
(SNSF) in the south, together known as Son-Narmada
(SONA) Fault System. The Late PalaeoproterozoicNeoproterozoic Vindhyan Supergroup of rocks are
exposed towards the north of this belt. In contrast,
towards the south, a vast expanse of gneisses and
migmatites which mark the basement for Mahakoshal
sediments, are exposed along SNSF. The major rock
types of the Mahakoshal Group include metasedimentaries (quartzite-pellite-carbonate-greywacke BIF), subordinate metabasalt and minor ultra-mafics and
intrusive granitoids and sporadic mafic dyke swarms.
The pronounce granitic magmatic activities around
SNSF has makred around 1600 to1800 Ma. These are
exposed as plutons near Dudhi, Jabalpur and Jhirgadandi
shows their regional extend along SNSF. Field
characteristic shows presence of mafic micro-granular
enclaves (MMEs) and developement of acicular apatite.
Geochemically, they are meta- and peraluminous, subalkaline to calc-alkaline, hybrid type (S-type granite) and
emplaced during post-orogenic stage. It also have high
whole-rock Al O /TiO ratios and A/CNK plots, confirm
its origin through partial melting of meta-sedimentary
rocks.
The metapelitic sequence of the Parsoi Formation
of the Mahakoshal Group, represented dominantly by
phyllite, is exposed in the area and has mineral assemblages akin to greenschist facies. Phyllite displays
a well-developed schistosity and occurs in two varieties;
(a) fine-grained greenish grey andalusite bearing
muscovite phyllite; and (b) reddish-brown, medium-to
coarse-grained biotite phyllite/schist with andalusite. Its
protolith corresponds to fine-grained pelitic sediments
affected by metamorphism reaching the chlorite zone of
green-schist facies and showing lepidoblastic to granolepidoblastic textures defined by the alignment
micaceous minerals. In comparison, the latter has a
typical mineral assemblage of biotite + quartz +
muscovite + chlorite. These rocks belong to the biotite
zone of greenschist facies, indicating a slightly higher
grade than the chlorite zone fringing the contact aureole
of a granitic pluton in the area.
Two distinct zones representing contact metamorphic facies within the aureole have been
identified. The outer zone of contact aureole display
assemblage comprising the phases quartz+ albite+
muscovite+ chlorite+ biotite+ andalusite in the albiteepidote-hornfels facies. Subsequently, the inner zone,
adjacent to the pluton, contains an assemblage of quartz+
plagioclase+ muscovite+ biotite + andalusite. The values
of Fe O (7.04 - 8.19%) andMgO (1.69- 2.07%) observed
in hornfelses are on the higher side as compared to the
andalusite bearing phyllite (Fe O 5.74 – 7.7% and MgO
0.79- 1.59%) of the area. This implies that the enrichment
of Fe is in along the Mg-rich minerals (Biotite) zone. The
low-grade regionally metamorphosed greenschist facies
(M ) of the Parsoi Formation shows overprinting of
Hornblende-Hornfels facies of contact metamorphic
assemblages (M )inthe adjoining areas ofthe pluton.
vastness in time and space with an emphasis on atmosphere, climate, sedimentary cover, and life. The
Sohagi Ghat section in the Rewa district of Madhya Pradesh exposes the topmost part of the Kaimur
Group represented by the white to buff-colored Dhandraul Quartzite (sandstone) Formation. The
overlying Rewa Group is differentiated into Panna shale, Lower Rewa sandstone, Jhiri shale, and Upper
Rewa sandstone formations. The cyclicity of the thick sequence of arenaceous sediments interbedded
with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the
regressive strand of sea changes.
In the Sohagi Ghat section, the Panna Formation shows three major lithofacies, identified as, Thinly
bedded siltstone facies (TBSF), Silty-shaly facies (SSF), and Interbedded sandstone-siltstone facies
(ISSF). It is characterized by an interbedded sequence of very thin to thinly laminated shale and very
fine-grained sandstone with thick beds of siltstone/shale. At places, the shales are calcareous in nature.
The Lower Rewa sandstone (=Asan sandstone) is sandwiched between the Panna shale below and the
Jhiri shale above in the area. The shaly, shelfal succession of the Rewa shale as a deep-water succession
punctuated by wedge-shaped sandstone and/or conglomerate bodies occurring at multiple
stratigraphic levels. These wedge-shaped sandstone and/or conglomerate units as regressive wedges
with varying depositional environments. The lithofacies associations of the heterolithic Lower Rewa
Sandstone can be classified as i) Sandstone lithofacies association ii) Siltstone lithofacies association
and iii) Shale lithofacies association. Sandstone lithofacies association consists of fine to very-finegrained sandstone with an average thickness of about 55 cm (maximum 3 m thick). The sedimentary
structure viz. planar cross-bedding, trough cross-bedding with mud drapes low angle discordances,
interference ripples, current ripple, cuspate ripple, flute cast, furrow & ridge etc. present in the
sandstone lithofacies association is indicative of sand flat environment of deposition within upper
subtidal to intertidal domain. The syn-sedimentary deformation structures observed at places within
the sandstone are due to the quick deposition of water-saturated sediments that expel water causing
liquefaction and deformation. Flute casts occur abundantly in shallow water marine as well as in the
nomenclature. These studies require the combination of purely scientific, practical and geological as
well as non-geological tasks by the geoscientists. The exploration, reporting and preparation of an
inventory of geologically unique localities and their protection and preservation is a need of the hour
in India. Geological mapping along the Sohagighat road section, Rewa district, Madhya Pradesh has
allowed us to realize the uniqueness of exposures of marine sedimentary structures in the Upper
Vindhyan Group of rocks in its eastern extremities. These outcrops along the national highway
NH-7 provide an opportunity to establish this approximately 2km road section as a geoheritage site
(geosites).
Along the Sohagighat section, the Kaimur Group is represented by white to buff-coloured
Dhandraul Quartzite (sandstone) Formation. The overlying Rewa Group is differentiated into
four formations i.e., Panna Shale, Lower Rewa Sandstone, Jhiri Shale and Upper Rewa Sandstone
formations. The Panna Shale Formation is characterized by an interbedded sequence of very thinly to
thinly laminated shale and very fine-grained sandstone with thick beds of siltstone/shale. At places,
the shale is calcareous. The Lower Rewa Sandstone is a hetero-lithic formation with sandstone-
siltstone-shale repetitive package. The Jhiri Formation is characterized by maroon, purple to
green coloured, very fine-grained (silt to clay size) rock. The Upper Rewa Sandstone Formation is
characterized by purplish to white, very fine to medium-grained arenitic sandstone, and occurs as
a cliff.
This section exemplifies an array of sedimentary structures seldom observed in one place with
good exposures expressing elaborate details. The primary sedimentary structure observed within the
different formations of Rewa Group is parallel lamination, planar cross beds, tidal bundles, trough
cross-beds, hummocks and swales, wavy beds, ripples, flute cast, syneresis cracks, wrinkle marks,
mud cracks, sole mark, tool marks, gutter casts, septarian nodules besides preserved algal mats in
the form of microbial induces sedimentary structure (MISS) and pen-contemporaneous structures.
The availability of well-preserved sedimentary structures is due to the largely undeformed and
unmetamorphosed nature of the terrain and the variety of primary marine sedimentary structures
exposed along the road sections makes it suitable to develop as a geoheritage site.
As the marine sedimentary structures are the result of the different sedimentary processes
involved during the time of deposition, this section demonstrates variety of sedimentary features
which are significant for geological research. Thus, it can also be exploited efficiently for training
professionals, researchers and students specializing in marine sedimentary processes besides
regular visitors. The road maintenance and rock-falls, vegetation expansion, and irresponsibility
of occasional visitors (rock graffiti and garbage dumping) are potential dangers for this potential
geoheritage site. A suitably designed conservation plan, in consultation with the local authorities
and highway authorities, needs to be developed.
Craton in Central India. The celebrated hill fort of Kalinjar (Kalanjar) is one of the areas where
it shows the typical Eparchean unconformity that marks the transition between the Archean and
Proterozoic eons in Earth's history. The Kalinjar Fort is situated in the village of Tarahati under
the Naraini tehsil, Banda district, in the Bundelkhand region in Uttar Pradesh on the border with
Madhya Pradesh. It stands on an isolated flat-topped hill comprised of Kaimur sandstone resting
unconformably over the Bundelkhand granitoid Complex (BGC), which rises 244m above the plain.
The Chandela Fort is aligned in an east-west direction, being nearly 2km in length and 800m in
breadth. It is built on strong 25-30m wide foundations and has a height of around 30-25m with 8m
wide summit. The material used in its construction is the large sandstone and granite pieces derived
from the nearby localities.
The Kalinjar Fort is one of the largest and unbeatable forts of medieval India, which incorporates
many styles of architecture in this fort viz. the Gupta style, Pratihara style, Panchayatan Nagar style
etc. The name of Kalanjaradri, or the hill of Kalinjara, is said to have been derived from Siva himself,
who, as Kala, or "Time", causes all things to decay (jar), and who is, therefore, the destroyer of all
things, and the god of death. There are two entrances to the fort of Kalinjar, of which the principal
is on the north side and the other at the southeast end leading towards Panna. Besides architectural
antiquity, there are several mythological places and sculptures within the fort premises. One of
the small caves, called as Sitasej, contains a stone bed and pillow. The Patal Ganga is a large deep
well, or reservoir, cut in the rock, while the Pandu-kund is a shallow circular basin, about 12 feet in
diameter, into which the water is constantly trickling from the crevices. There is a colossal figure of
Kal Bhairav, which has 18 arms with the usual garland of skulls, snake earrings, snake armlets and
a serpent twined around the neck. Several broken pieces of sacred sculpture tell about the cultural
richness and diversity as most are centuries old.
Geologically, the Vindhyan sedimentary basin is one of the largest repositories of undeformed
sediments deposited over a long time. Approximately 800m before the main entrance of the fort,
the geological boundary is between sedimentary rocks of the Vindhyan Supergroup, 1400 million
years old, and Archaean rocks comprising granites that are more than 2000 million years old. This
boundary represents an area that witnessed a significant change in the Earth's tectonics and climate
systems. It is characterized by a period of erosion and non-deposition that led to the formation of
nonconformity, where the older Archean rocks are overlain by relatively younger Proterozoic rocks
deposited in one of the Purana basins. This unconformity separates the Proterozoic Kaimur sandstone
(1200 Ma) and Bundelkhand granite (more than 2000 Ma) with relatively younger intrusive dolerite
dykes, representing a time gap of approx. 600 Ma, which is a period of remarkable gap in geological
history. This unconformity indicates the enormous time gap in the creation of the earth's crust.
The approach road from the village Tarahati to Kalinjar Fort provides an opportunity to attract
potential visitors for its geological importance before looking into the history and architecture of
the fort. The road maintenance, vegetation expansion, and irresponsibility of occasional visitors
(rock graffiti and littering) are potential dangers to this geo-heritage site. As the fort is conserved and maintained by the Archaeological Survey of India (ASI), a suitably designed conservation plan
expressing its geological importance of this geoheritage site, also needs to be developed to address
these issues.
Geomorphologically the area is divided into highly dissected hills, moderately dissected
hills, low dissected hills, pediment, pediplain and gentle undulating plain. The central and north-
eastern part of the areas is dominated by hills and the northern and southern portion of the area is
represented by plains. The dendritic pattern is the dominant drainage pattern observed in the area,
however radial drainage pattern in the central part and parallel drainage pattern at few locations
are also observed. Geologically, the study area shows exposures of lithounits belonging to Bhauri
and Manikpur formations of Kaimur Group and Jhiri Shale Formation of Rewa Group of Vindhyan
Supergroup. In the study area, the Bhauri Formation is represented by sandstone. Megascopically,
sandstone is thinly bedded, laminated, pitted and fined to medium-grained. Manikpur Formation is
represented by white coloured, fined grained sandstone and whitish grey/greyish white coloured,
fine to medium-grained orthoquartzite which at places is ferruginous in nature. The overlying Rewa
Group is represented by thinly laminated shale belonging to Jhiri Formation. The low-lying areas
are covered by the Banda Alluvium of quaternary ages.
The statistical analysis of a total of 182 nos of composite samples revealed that the values of
Lead (Pb) in 158 samples are above 36.62ppm. The minimum value of Pb in the analytical data
is 18ppm whereas the maximum value is 260ppm. The mean value of Pb in the analytical data is
31ppm. The median is 26.8ppm, the mode is 25ppm and the standard deviation is 22ppm while
the threshold value is 34.4ppm. The population is positively skewed (7.88) and leptokurtic (75.08).
The dispersion pattern occurs in the central and southern parts of the area around Hardoha, Madri,
Khaira, Champagarh, and Baraiti Bari villages of Rewa district of Madhya Pradesh. The underlying
lithologies are sandstone of Kaimur Group of the Vindhyan Supergroup.
The concentration of Chromium (Cr) in the area varies from 72 to 169ppm with a mean of
121.04ppm and a median of 120ppm. The threshold value in the area is 141ppm. The population is
positively skewed (0.098) and leptokurtic (0.456). The geochemical dispersion pattern of Cr indicates
a relatively higher concentration across all the formations as well as over the Banda Alluvium, in the
northern part of the area.
The concentration of Zirconium (Zr) in the area varies from 294 to 703ppm with a mean of
480.560ppm and a median of 483.5ppm. The population is positively skewed (0.068) and platykurtic
(-0.800). The threshold value in the area is 624.5ppm. The geochemical dispersion pattern of Zr
indicates a relatively higher concentration in the central part of the area over Manikpur Formation.
The concentration of Arsenic (As) in the area varies from 1.5 to 16.890ppm with a mean of
6.505ppm and a median of 5.9ppm. The population is positively skewed (1.372) and leptokurtic
(1.820). The threshold value in the area is 8.5ppm. The geochemical dispersion pattern of As
indicates a relatively higher concentration in the central and eastern parts of the area over Manikpur
Formation and Banda Alluvium respectively.
The concentration of Hafnium (Hf) in the area varies from 8.230 to 21.130ppm with a mean
of 14.557ppm. The population is positively skewed (0.166) and platykurtic (-0.365). The threshold
value in the area is 18.156ppm. The geochemical dispersion pattern of Hf indicates a relatively higher
concentration in the southwestern, central and northeastern parts of the area over the Manikpur
Formation, Bhauri Formation and Banda Alluvium respectively.
The enrichment of the concentration of Pb-11 ppm, Cr-106 ppm and Zr-121ppm follows the
topography and drainage system indicating the sandstone of Manikpur Formation of Kaimur
Group and its equivalent Dhandraul Formation is considerably probable source of enrichment of
Pb, Cr, Zr, in the area. The provenance of these formations is again from the weathering products of
Bundelkhand Granitoid Complex (BGC) and older metamorphic occurring as xenoliths.
Group and are widely dispersed in Vindhyan basin. It consists of thick arenite-argillite sequence
with a thickness of approx 365m. The Dhandraul Sandstone Formation of Kaimur Group forms the
top most unit of this group. The sandstone comprises of very fine to medium grained whitish, dirty
white, pinkish and purple coloured sub-litharenite to quartz arenite which is cemented mainly by
secondary silica to form hard and compact rock. The beds are thinly to very thickly bedded ranges
from 10cm to more than 1.0m and shows both coarsening as well as bed thickening succession towards
top. The sedimentary structures observed in the Dhandraul Sandstone are mainly small to large scale
trough and planar cross beds, tidal bundles, ripple marks and PCD structures. Petrographically, the
sandstone is fine to coarse grained in nature and made up of monocrystalline quartz ranging in
between 85-95%. The matrix is less than 15%. Feldspar and lithic fragments together constitute in
between 4-15% in the groundmass. Mica constitutes only 1%. Clasts are sub-angular to sub-rounded with moderate to well sorting. The sandstone is textually and mineralogically mature. Zircon, rutile,
biotite, magnetite and tourmaline are common heavy minerals in the groundmass.
Geochemical plots using major oxides ratios suggests that Dhandraul Sandstone has a wide
range of geochemical composition ranges from sub-litharenite to quartz arenite. Ternary plot (Blatt
et al., 1980) suggests that sandstones are mainly ferromagnesium potassic to potassic in composition.
Ternary plot of Th, Zr and Sc (Bhatia & Crook, 1986) indicates that sandstone was deposited under
active to passive continental margin. Tectonic discrimination diagrams suggest that sandstone was
formed under craton interior to recycled orogens setting. Binary plot of TiO2 vs Zr (Hayashi et al.,
1997) shows that, the source for these sandstone sediments were igneous rocks of intermediate to
felsic composition. Chemical index of alteration (CIA) and index of compositional variation (ICV)
indicates moderate to high degree of alteration and also suggests well maturity. Similarly, plagioclase
alteration index (PAI) also suggests intense destruction of feldspars from source during weathering,
transport, sedimentation, and diagenesis in humid condition.
Thus, it can be concluded that, the variation in chemical composition of the sandstone of
Dhandraul Formation is mainly controlled by the combined effect of alteration indices of chemical
weathering faced during prolonged cycles of transportation and sedimentation.
storehouse of critical mineral concentrations like V, Ti, Sc, Ga and Zr, etc. Being ubiquitously
developed on the top surface of both Dhandraul and Scarp Sandstone in and around Chitrakoot area
of Uttar Pradesh, these lateritic horizons have gone through the pedogenic process, formation of
pisolitic structures, the concentration of iron, aluminium along with other essential trace elements,
which further makes the study of this lateritic horizon more critical. Hence, the petrographic
studies, trace element concentrations (ICPMS data), and SEM analysis revealed these lateritic
horizons' mineral potential. The lateritic rocks mainly comprise limonite, gibbsite, magnetite and
hematite. Petrographic observations of laterite over the Dhandraul quartz arenite reveal that all the
silicate minerals have been transformed into a mixture of Fe and Al oxide and hydroxides. Hence,
the samples mainly contain goethite and limonite as essential minerals and quartz as accessory
minerals. Goethite is showing typical colloform banding. Colloform banding can be very well
appreciated both under transmitted and reflected light. Limonite is characterized by its yellow
internal reflection. The petrographic studies further show that the goethite minerals underwent
alteration and formed bauxite minerals such as gibbsite and boehmite. The presence of gibbsite is
more where the lateralization is gradually more. The pisolitic texture and progressive lateralization
are also observed in the samples. The development of pissolitic textures suggests that they are
further in the process of bauxite formation. This pissolite probably represents bohemite. All these
progressive and intense lateralization and bauxitization processes have led to the leaching of mobile
silicate phases and the concentration of less mobile trace elements along with Fe and Al. The trace
element concentration in the bauxite layers for a few samples shows interesting results, i.e., V (avg.
1120ppm), Zr (avg. 325.85ppm), Ba (avg. 253ppm) and Sc (avg. 93.45ppm). The SEM studies of the
lateritic horizons further (point, line, and bulk analysis) show values for Sc varying between 900 to
1600ppm. The spatial spread of this lateritic horizon is vast; however, the thickness is maximum
up to 2.5m to 3m. These lateritic horizons are well spread over an extensive area, much beyond
the scope of the present study. However, the majority of land falls in agricultural and forest areas.
Hence it would be difficult to propose immediate programs for exploration in these areas, however,
future exploration possibilities cannot be ruled out.
of the Kaimur Group of the Vindhyan Supergroup. Exposed outcrops and cliffs were examined
in detail by section measurement and sedimentary logs were created. The logs are categorized
bed by bed into several facies according to lithology and sedimentary structures. The focus was to
identify the facies succession and to analyze the depositional environment of Dhandraul and Scarp
Sandstone formations.
The Scarp Formation comprises six sub-facies namely sandstone with tidal bundles sub-facies,
planar cross-bedded facies, herringbone cross-bedded facies, ripples with mud crack, parallel
laminated sandstone and trough cross-bed facies. Trough cross bed facies sandstone is thin to
medium bedded, fine-grained immature quartzo-felspathic sandstone having erosional surfaces at
the top. Trough beds with ripple at the top are characteristic of unidirectional flow and indicate a
shallow marine condition, these sub facies are found in association with sandstone having tidal
bundle sub-facies, which is thin to medium bedded, fine-grained sandstone. These sub-facies are
characteristics feature of the tidal-influenced shallow marine environment which is formed by the
periodic activity of flood flow and ebb flow during spring and neap tide. The presence of scour
surfaces at the top of the sandstone having tidal bundles indicates features of high energy condition,
which causes the flute casts under flood flow during the deposition above the fair weather base.
Overall, the Scarp Formation suggests a subtidal to intertidal environment of deposition.
The Dhandraul Sandstone Formation comprises five sub-facies namely, planar cross-bedded
sub-facies, trough cross bed facies, sandstone having tidal bundle facies, and herringbone sandstone
sub-facies. The presence of sandstone having tidal bundle facies with herringbone sub-facies is
typical of the intertidal zone, where neap and spring tide dominates. These sub-facies association is
overlain by sub-facies of medium to coarse-grained planar cross-bed and trough cross-bedded sub-
facies. The grain size of the sediment coarsening sequence, as well as the bed thickening sequence,
suggests shallowing of the basin with a repetitive cycle of bed thickening and thinning. Overall, this
unit shows intertidal to supratidal zone of deposition.
Granulometric analysis of samples from the Dhandraul Sandstone Formation shows that
interbeds of the formation have size < (Φ) 3.75 (Very fine sand) to (Φ) -0.2 (Pebbly sand). The analysis
results show that a very less amount of sediments is also present which is less than < (Φ) 3.75. The
presence of the pebbly nature of grains at the top of the bed either indicates high energy conditions
during the sedimentation to drag out coarser sediments or there should be a break in sedimentation.
17
On the other hand, Scarp Sandstone Formation have sizes from < (Φ) 3.75 (Very fine sand) to (Φ)
0.75 (Coarse sand). The average value of skewness of the sediment shows positive nature indicating
moderate sorting.
The paleocurrent data collected from planar cross beds (28 azimuths) show a mean azimuth of
230o
-355 o whereas trough beds (180 azimuths) range between 250 o
-355 o
. The ripple shows azimuth
between 35o
-340o whereas 17 nos. of parting lineations shows the trend between 260o
-355 o
. It is
inferred that the granite, granodiorite, gneiss, and metasedimentary rocks of the Mahakoshal Group
and Chotanagpur granite–gneiss present in the eastern and southeastern direction may be the
possible source rocks for the Kaimur Group.
Quartzite. The Rewa Group is differentiated into Panna Shale, Lower Rewa Sandstone, Jhiri Shale
and Upper Rewa Sandstone formations. The cyclicity of the thick sequence of arenaceous sediments
interbedded with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the regressive strand of sea changes. The preservation of stratal assemblages in the Rewa
Group of rocks is discernible as the influence of deformation and metamorphism is absent or rare.
The Panna Formation shows three major lithofacies, identified as, thinly bedded siltstone facies (TBSF), silty-shaly facies (SSF), and interbedded sandstone-siltstone facies (ISSF). It is characterized
by an interbedded sequence of very thin to thinly laminated shale and very fine-grained sandstone
with thick beds of siltstone/shale. At places, the shales are calcareous. The Lower Rewa Sandstone
(=Asan Sandstone) is shaly, shelfal succession punctuated by wedge-shaped sandstone bodies are
regressive wedges with varying depositional environments and occurring at multiple stratigraphic
levels. Based on the lithological characteristics the Lower Rewa Sandstone can be subdivided into
three lithofacies i) Sandstone lithofacies ii) Siltstone lithofacies and iii) Shale lithofacies. The sandstone
lithofacies comprises fine to very fine-grained sandstone and sedimentary structures present in it are
suggestive of deposition in intertidal domain.
The overlying Jhiri Shale Formation is classified as (i) Silty-Sandy facies (SStF) and (ii), Silty-
Shaly facies (SShF). The SStF litho-facies comprises an interbedded sequence of silty and sandy
component, where the silty component is more and sequence is very thinly laminated to thinly bedded
in nature, having thickness more than 10-12m with fining upward sequence and the sandstone-
siltstone hetrolithic units are the most common characteristic features signifying intermediate
fluctuation of flow. The silty-shaly facies (SShF) consist primarily of silty and, to a lesser degree,
shaly sequences. This sequence of Jhiri Shale Formation comprises of silty sand in the lower part
followed upward by the silty shaly facies. The silty sandy facies comprise of interbedded sequence
of siltstone and sandstone having swales and hummocky cross-stratification suggesting deposition
in between storm and fair weather wave base under the lower shoreface in transgression. Overall,
this sequence suggests a transitional environment between lower shore to offshore depositional
settings. The Upper Rewa Sandstone has been divided into five facies (i) Liquefied Sandstone (LSt)
(ii) Low Angle Parallel Bedded Sandstone (LAPBSt), (iii) Fine-grained Sandstone (FSt), (iv) Cross-
bedded Sandstone (CBSt), (Large-scale Planar Cross-bedded Sandstone, Herringbone Cross-bedded
Sandstone, Large-scale Trough Cross-bedded Sandstone), (v) Ripple Laminated Silt-mudstone
(RLSiM) which indicates the tide and wave-dominated shoreface environment of deposition.
The Rewa succession, exposed at the Sohagi ghat section, is composed of shale and sandstone
with primary and penecontemporaneous structures, which facilitated facies analysis of these
sediments. The lithological characters, facies associated with them and sedimentary structures
indicate that Panna Formation is of foreshore to shoreface depositional environment. Lower Rewa
Sandstone suggests a tidal flat environment of deposition. Jhiri Formation suggests an outer shelf
15
environment of a deposition while that of the Upper Rewa Sandstone Formation indicates a tide
and wave-dominated shore-face environment of deposition. It is difficult to confirm that cyclicity is caused by a mechanism with a constant time but the regular interval of bedding and cyclic sequences reflects allogenetically controlled periodicity.
Abstract No: T1/P-16
Tectonic Signatures of Passive Margin Settings of the Vindhyan Sequence in Son
Valley, Central India
Hemant Kumar, Ajay Shanker Pandey, Sibabrat Nayak and Sanjiv Kumar
Geological Survey of India, Northern Region, Lucknow
The Vindhyan sedimentary basin of north western and central India is one of the largest
undeformed, Meso-Neoproterozoic basins in the world. During the Proterozoic, the continental crust
witnessed the extensive development of intra-cratonic basins when the thick sedimentary strata
were deposited in these un-metamorphosed basins. The intra-cratonic Vindhyan basin developed
in the central and north-western part of the Indian shield is the largest and thickest Proterozoic
sedimentary succession of India which records the longest depositional histories in terms of its
vastness in space and time. Thus, the study across this basin may help in understanding paleo-
reconstructions, sediment source determination, and the evolution of plate tectonics processes.
The present studies of Vindhyan Supergroup of sediments in the Son Valley sector in the
Central India, reveal that the distinct set of lineaments trending (ENE-WSW) along the Son-Narmada
lineament is responsible for carving out the present configuration of the Vindhyan basin. There
appears to be a series of movements along these geo-sutures which follows the same trend as well
as the N-S, sympathetic faults with attendant cross faults developed along the southern margin of
the basin.
The tectonic discrimination diagrams (SiO2 vs Log K2O/Na 2
O) suggests the passive continental
margin setting for the deposition of the sandstones of Dhandraul Formation, Kaimur Group as well
as Upper Rewa and Lower Rewa Sandstone formations, Rewa Group. The passive margins are
considered to be less deformed but post-continental break-up deformation and associated uplift
have been recorded in the area around Shankergarh area in Prayagraj district, Uttar Pradesh, and
Sohagighat areas in Rewa district, Madhya Pradesh.
Along the Sohagighat section, a reverse fault has been observed along the ENE-WSW direction
with an inclination of approximately 28° towards the south-west. As the thrust faults are commonly
associated with the deformation of layered sediments, especially in passive margins, it signifies
the post-break-up incipient shortening and thickening of the strata, under the action of horizontal
compression which originates due to ridge push. Here the movement of the hanging wall up and
over the footwall material creates the canonical stratigraphic succession, wherein the sedimentary
strata of the Panna Formation are repeated. The density exerts a major control on the vergence of
thrusting and the sedimentary layering provides a pre-existing mechanical anisotropy along which
faults propagate. This provides ideal initial conditions for ramp-flat geometries as evident here.
Talks by Hemant Kumar
rock samples obtained from the exploratory boreholes.
Geologically it is formed by hard graniterock layers of Gneissic complex of Protozoic era. Exfoliation joints of
2cm to 10 cm are usually observed with spillage. Many remedial measures like filters, clay blankets and
Geosynthetic jutes can be applied to control it. Use of Bentonite with plasticizer is recommended for cheap and
best remedial measures.
northern part of CITZ. The meta-sediments of MSB are
subjected to polyphase tectono-thermal events involving
several cycles of volcano-sedimentary deposition,
deformation, metamorphism and magmatism. The
crustal-scale Son-Narmada North Fault (SNNF) delimits
this belt in the north and Son-Narmada South Fault
(SNSF) in the south, together known as Son-Narmada
(SONA) Fault System. The Late PalaeoproterozoicNeoproterozoic Vindhyan Supergroup of rocks are
exposed towards the north of this belt. In contrast,
towards the south, a vast expanse of gneisses and
migmatites which mark the basement for Mahakoshal
sediments, are exposed along SNSF. The major rock
types of the Mahakoshal Group include metasedimentaries (quartzite-pellite-carbonate-greywacke BIF), subordinate metabasalt and minor ultra-mafics and
intrusive granitoids and sporadic mafic dyke swarms.
The pronounce granitic magmatic activities around
SNSF has makred around 1600 to1800 Ma. These are
exposed as plutons near Dudhi, Jabalpur and Jhirgadandi
shows their regional extend along SNSF. Field
characteristic shows presence of mafic micro-granular
enclaves (MMEs) and developement of acicular apatite.
Geochemically, they are meta- and peraluminous, subalkaline to calc-alkaline, hybrid type (S-type granite) and
emplaced during post-orogenic stage. It also have high
whole-rock Al O /TiO ratios and A/CNK plots, confirm
its origin through partial melting of meta-sedimentary
rocks.
The metapelitic sequence of the Parsoi Formation
of the Mahakoshal Group, represented dominantly by
phyllite, is exposed in the area and has mineral assemblages akin to greenschist facies. Phyllite displays
a well-developed schistosity and occurs in two varieties;
(a) fine-grained greenish grey andalusite bearing
muscovite phyllite; and (b) reddish-brown, medium-to
coarse-grained biotite phyllite/schist with andalusite. Its
protolith corresponds to fine-grained pelitic sediments
affected by metamorphism reaching the chlorite zone of
green-schist facies and showing lepidoblastic to granolepidoblastic textures defined by the alignment
micaceous minerals. In comparison, the latter has a
typical mineral assemblage of biotite + quartz +
muscovite + chlorite. These rocks belong to the biotite
zone of greenschist facies, indicating a slightly higher
grade than the chlorite zone fringing the contact aureole
of a granitic pluton in the area.
Two distinct zones representing contact metamorphic facies within the aureole have been
identified. The outer zone of contact aureole display
assemblage comprising the phases quartz+ albite+
muscovite+ chlorite+ biotite+ andalusite in the albiteepidote-hornfels facies. Subsequently, the inner zone,
adjacent to the pluton, contains an assemblage of quartz+
plagioclase+ muscovite+ biotite + andalusite. The values
of Fe O (7.04 - 8.19%) andMgO (1.69- 2.07%) observed
in hornfelses are on the higher side as compared to the
andalusite bearing phyllite (Fe O 5.74 – 7.7% and MgO
0.79- 1.59%) of the area. This implies that the enrichment
of Fe is in along the Mg-rich minerals (Biotite) zone. The
low-grade regionally metamorphosed greenschist facies
(M ) of the Parsoi Formation shows overprinting of
Hornblende-Hornfels facies of contact metamorphic
assemblages (M )inthe adjoining areas ofthe pluton.
vastness in time and space with an emphasis on atmosphere, climate, sedimentary cover, and life. The
Sohagi Ghat section in the Rewa district of Madhya Pradesh exposes the topmost part of the Kaimur
Group represented by the white to buff-colored Dhandraul Quartzite (sandstone) Formation. The
overlying Rewa Group is differentiated into Panna shale, Lower Rewa sandstone, Jhiri shale, and Upper
Rewa sandstone formations. The cyclicity of the thick sequence of arenaceous sediments interbedded
with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the
regressive strand of sea changes.
In the Sohagi Ghat section, the Panna Formation shows three major lithofacies, identified as, Thinly
bedded siltstone facies (TBSF), Silty-shaly facies (SSF), and Interbedded sandstone-siltstone facies
(ISSF). It is characterized by an interbedded sequence of very thin to thinly laminated shale and very
fine-grained sandstone with thick beds of siltstone/shale. At places, the shales are calcareous in nature.
The Lower Rewa sandstone (=Asan sandstone) is sandwiched between the Panna shale below and the
Jhiri shale above in the area. The shaly, shelfal succession of the Rewa shale as a deep-water succession
punctuated by wedge-shaped sandstone and/or conglomerate bodies occurring at multiple
stratigraphic levels. These wedge-shaped sandstone and/or conglomerate units as regressive wedges
with varying depositional environments. The lithofacies associations of the heterolithic Lower Rewa
Sandstone can be classified as i) Sandstone lithofacies association ii) Siltstone lithofacies association
and iii) Shale lithofacies association. Sandstone lithofacies association consists of fine to very-finegrained sandstone with an average thickness of about 55 cm (maximum 3 m thick). The sedimentary
structure viz. planar cross-bedding, trough cross-bedding with mud drapes low angle discordances,
interference ripples, current ripple, cuspate ripple, flute cast, furrow & ridge etc. present in the
sandstone lithofacies association is indicative of sand flat environment of deposition within upper
subtidal to intertidal domain. The syn-sedimentary deformation structures observed at places within
the sandstone are due to the quick deposition of water-saturated sediments that expel water causing
liquefaction and deformation. Flute casts occur abundantly in shallow water marine as well as in the
nomenclature. These studies require the combination of purely scientific, practical and geological as
well as non-geological tasks by the geoscientists. The exploration, reporting and preparation of an
inventory of geologically unique localities and their protection and preservation is a need of the hour
in India. Geological mapping along the Sohagighat road section, Rewa district, Madhya Pradesh has
allowed us to realize the uniqueness of exposures of marine sedimentary structures in the Upper
Vindhyan Group of rocks in its eastern extremities. These outcrops along the national highway
NH-7 provide an opportunity to establish this approximately 2km road section as a geoheritage site
(geosites).
Along the Sohagighat section, the Kaimur Group is represented by white to buff-coloured
Dhandraul Quartzite (sandstone) Formation. The overlying Rewa Group is differentiated into
four formations i.e., Panna Shale, Lower Rewa Sandstone, Jhiri Shale and Upper Rewa Sandstone
formations. The Panna Shale Formation is characterized by an interbedded sequence of very thinly to
thinly laminated shale and very fine-grained sandstone with thick beds of siltstone/shale. At places,
the shale is calcareous. The Lower Rewa Sandstone is a hetero-lithic formation with sandstone-
siltstone-shale repetitive package. The Jhiri Formation is characterized by maroon, purple to
green coloured, very fine-grained (silt to clay size) rock. The Upper Rewa Sandstone Formation is
characterized by purplish to white, very fine to medium-grained arenitic sandstone, and occurs as
a cliff.
This section exemplifies an array of sedimentary structures seldom observed in one place with
good exposures expressing elaborate details. The primary sedimentary structure observed within the
different formations of Rewa Group is parallel lamination, planar cross beds, tidal bundles, trough
cross-beds, hummocks and swales, wavy beds, ripples, flute cast, syneresis cracks, wrinkle marks,
mud cracks, sole mark, tool marks, gutter casts, septarian nodules besides preserved algal mats in
the form of microbial induces sedimentary structure (MISS) and pen-contemporaneous structures.
The availability of well-preserved sedimentary structures is due to the largely undeformed and
unmetamorphosed nature of the terrain and the variety of primary marine sedimentary structures
exposed along the road sections makes it suitable to develop as a geoheritage site.
As the marine sedimentary structures are the result of the different sedimentary processes
involved during the time of deposition, this section demonstrates variety of sedimentary features
which are significant for geological research. Thus, it can also be exploited efficiently for training
professionals, researchers and students specializing in marine sedimentary processes besides
regular visitors. The road maintenance and rock-falls, vegetation expansion, and irresponsibility
of occasional visitors (rock graffiti and garbage dumping) are potential dangers for this potential
geoheritage site. A suitably designed conservation plan, in consultation with the local authorities
and highway authorities, needs to be developed.
Craton in Central India. The celebrated hill fort of Kalinjar (Kalanjar) is one of the areas where
it shows the typical Eparchean unconformity that marks the transition between the Archean and
Proterozoic eons in Earth's history. The Kalinjar Fort is situated in the village of Tarahati under
the Naraini tehsil, Banda district, in the Bundelkhand region in Uttar Pradesh on the border with
Madhya Pradesh. It stands on an isolated flat-topped hill comprised of Kaimur sandstone resting
unconformably over the Bundelkhand granitoid Complex (BGC), which rises 244m above the plain.
The Chandela Fort is aligned in an east-west direction, being nearly 2km in length and 800m in
breadth. It is built on strong 25-30m wide foundations and has a height of around 30-25m with 8m
wide summit. The material used in its construction is the large sandstone and granite pieces derived
from the nearby localities.
The Kalinjar Fort is one of the largest and unbeatable forts of medieval India, which incorporates
many styles of architecture in this fort viz. the Gupta style, Pratihara style, Panchayatan Nagar style
etc. The name of Kalanjaradri, or the hill of Kalinjara, is said to have been derived from Siva himself,
who, as Kala, or "Time", causes all things to decay (jar), and who is, therefore, the destroyer of all
things, and the god of death. There are two entrances to the fort of Kalinjar, of which the principal
is on the north side and the other at the southeast end leading towards Panna. Besides architectural
antiquity, there are several mythological places and sculptures within the fort premises. One of
the small caves, called as Sitasej, contains a stone bed and pillow. The Patal Ganga is a large deep
well, or reservoir, cut in the rock, while the Pandu-kund is a shallow circular basin, about 12 feet in
diameter, into which the water is constantly trickling from the crevices. There is a colossal figure of
Kal Bhairav, which has 18 arms with the usual garland of skulls, snake earrings, snake armlets and
a serpent twined around the neck. Several broken pieces of sacred sculpture tell about the cultural
richness and diversity as most are centuries old.
Geologically, the Vindhyan sedimentary basin is one of the largest repositories of undeformed
sediments deposited over a long time. Approximately 800m before the main entrance of the fort,
the geological boundary is between sedimentary rocks of the Vindhyan Supergroup, 1400 million
years old, and Archaean rocks comprising granites that are more than 2000 million years old. This
boundary represents an area that witnessed a significant change in the Earth's tectonics and climate
systems. It is characterized by a period of erosion and non-deposition that led to the formation of
nonconformity, where the older Archean rocks are overlain by relatively younger Proterozoic rocks
deposited in one of the Purana basins. This unconformity separates the Proterozoic Kaimur sandstone
(1200 Ma) and Bundelkhand granite (more than 2000 Ma) with relatively younger intrusive dolerite
dykes, representing a time gap of approx. 600 Ma, which is a period of remarkable gap in geological
history. This unconformity indicates the enormous time gap in the creation of the earth's crust.
The approach road from the village Tarahati to Kalinjar Fort provides an opportunity to attract
potential visitors for its geological importance before looking into the history and architecture of
the fort. The road maintenance, vegetation expansion, and irresponsibility of occasional visitors
(rock graffiti and littering) are potential dangers to this geo-heritage site. As the fort is conserved and maintained by the Archaeological Survey of India (ASI), a suitably designed conservation plan
expressing its geological importance of this geoheritage site, also needs to be developed to address
these issues.
Geomorphologically the area is divided into highly dissected hills, moderately dissected
hills, low dissected hills, pediment, pediplain and gentle undulating plain. The central and north-
eastern part of the areas is dominated by hills and the northern and southern portion of the area is
represented by plains. The dendritic pattern is the dominant drainage pattern observed in the area,
however radial drainage pattern in the central part and parallel drainage pattern at few locations
are also observed. Geologically, the study area shows exposures of lithounits belonging to Bhauri
and Manikpur formations of Kaimur Group and Jhiri Shale Formation of Rewa Group of Vindhyan
Supergroup. In the study area, the Bhauri Formation is represented by sandstone. Megascopically,
sandstone is thinly bedded, laminated, pitted and fined to medium-grained. Manikpur Formation is
represented by white coloured, fined grained sandstone and whitish grey/greyish white coloured,
fine to medium-grained orthoquartzite which at places is ferruginous in nature. The overlying Rewa
Group is represented by thinly laminated shale belonging to Jhiri Formation. The low-lying areas
are covered by the Banda Alluvium of quaternary ages.
The statistical analysis of a total of 182 nos of composite samples revealed that the values of
Lead (Pb) in 158 samples are above 36.62ppm. The minimum value of Pb in the analytical data
is 18ppm whereas the maximum value is 260ppm. The mean value of Pb in the analytical data is
31ppm. The median is 26.8ppm, the mode is 25ppm and the standard deviation is 22ppm while
the threshold value is 34.4ppm. The population is positively skewed (7.88) and leptokurtic (75.08).
The dispersion pattern occurs in the central and southern parts of the area around Hardoha, Madri,
Khaira, Champagarh, and Baraiti Bari villages of Rewa district of Madhya Pradesh. The underlying
lithologies are sandstone of Kaimur Group of the Vindhyan Supergroup.
The concentration of Chromium (Cr) in the area varies from 72 to 169ppm with a mean of
121.04ppm and a median of 120ppm. The threshold value in the area is 141ppm. The population is
positively skewed (0.098) and leptokurtic (0.456). The geochemical dispersion pattern of Cr indicates
a relatively higher concentration across all the formations as well as over the Banda Alluvium, in the
northern part of the area.
The concentration of Zirconium (Zr) in the area varies from 294 to 703ppm with a mean of
480.560ppm and a median of 483.5ppm. The population is positively skewed (0.068) and platykurtic
(-0.800). The threshold value in the area is 624.5ppm. The geochemical dispersion pattern of Zr
indicates a relatively higher concentration in the central part of the area over Manikpur Formation.
The concentration of Arsenic (As) in the area varies from 1.5 to 16.890ppm with a mean of
6.505ppm and a median of 5.9ppm. The population is positively skewed (1.372) and leptokurtic
(1.820). The threshold value in the area is 8.5ppm. The geochemical dispersion pattern of As
indicates a relatively higher concentration in the central and eastern parts of the area over Manikpur
Formation and Banda Alluvium respectively.
The concentration of Hafnium (Hf) in the area varies from 8.230 to 21.130ppm with a mean
of 14.557ppm. The population is positively skewed (0.166) and platykurtic (-0.365). The threshold
value in the area is 18.156ppm. The geochemical dispersion pattern of Hf indicates a relatively higher
concentration in the southwestern, central and northeastern parts of the area over the Manikpur
Formation, Bhauri Formation and Banda Alluvium respectively.
The enrichment of the concentration of Pb-11 ppm, Cr-106 ppm and Zr-121ppm follows the
topography and drainage system indicating the sandstone of Manikpur Formation of Kaimur
Group and its equivalent Dhandraul Formation is considerably probable source of enrichment of
Pb, Cr, Zr, in the area. The provenance of these formations is again from the weathering products of
Bundelkhand Granitoid Complex (BGC) and older metamorphic occurring as xenoliths.
Group and are widely dispersed in Vindhyan basin. It consists of thick arenite-argillite sequence
with a thickness of approx 365m. The Dhandraul Sandstone Formation of Kaimur Group forms the
top most unit of this group. The sandstone comprises of very fine to medium grained whitish, dirty
white, pinkish and purple coloured sub-litharenite to quartz arenite which is cemented mainly by
secondary silica to form hard and compact rock. The beds are thinly to very thickly bedded ranges
from 10cm to more than 1.0m and shows both coarsening as well as bed thickening succession towards
top. The sedimentary structures observed in the Dhandraul Sandstone are mainly small to large scale
trough and planar cross beds, tidal bundles, ripple marks and PCD structures. Petrographically, the
sandstone is fine to coarse grained in nature and made up of monocrystalline quartz ranging in
between 85-95%. The matrix is less than 15%. Feldspar and lithic fragments together constitute in
between 4-15% in the groundmass. Mica constitutes only 1%. Clasts are sub-angular to sub-rounded with moderate to well sorting. The sandstone is textually and mineralogically mature. Zircon, rutile,
biotite, magnetite and tourmaline are common heavy minerals in the groundmass.
Geochemical plots using major oxides ratios suggests that Dhandraul Sandstone has a wide
range of geochemical composition ranges from sub-litharenite to quartz arenite. Ternary plot (Blatt
et al., 1980) suggests that sandstones are mainly ferromagnesium potassic to potassic in composition.
Ternary plot of Th, Zr and Sc (Bhatia & Crook, 1986) indicates that sandstone was deposited under
active to passive continental margin. Tectonic discrimination diagrams suggest that sandstone was
formed under craton interior to recycled orogens setting. Binary plot of TiO2 vs Zr (Hayashi et al.,
1997) shows that, the source for these sandstone sediments were igneous rocks of intermediate to
felsic composition. Chemical index of alteration (CIA) and index of compositional variation (ICV)
indicates moderate to high degree of alteration and also suggests well maturity. Similarly, plagioclase
alteration index (PAI) also suggests intense destruction of feldspars from source during weathering,
transport, sedimentation, and diagenesis in humid condition.
Thus, it can be concluded that, the variation in chemical composition of the sandstone of
Dhandraul Formation is mainly controlled by the combined effect of alteration indices of chemical
weathering faced during prolonged cycles of transportation and sedimentation.
storehouse of critical mineral concentrations like V, Ti, Sc, Ga and Zr, etc. Being ubiquitously
developed on the top surface of both Dhandraul and Scarp Sandstone in and around Chitrakoot area
of Uttar Pradesh, these lateritic horizons have gone through the pedogenic process, formation of
pisolitic structures, the concentration of iron, aluminium along with other essential trace elements,
which further makes the study of this lateritic horizon more critical. Hence, the petrographic
studies, trace element concentrations (ICPMS data), and SEM analysis revealed these lateritic
horizons' mineral potential. The lateritic rocks mainly comprise limonite, gibbsite, magnetite and
hematite. Petrographic observations of laterite over the Dhandraul quartz arenite reveal that all the
silicate minerals have been transformed into a mixture of Fe and Al oxide and hydroxides. Hence,
the samples mainly contain goethite and limonite as essential minerals and quartz as accessory
minerals. Goethite is showing typical colloform banding. Colloform banding can be very well
appreciated both under transmitted and reflected light. Limonite is characterized by its yellow
internal reflection. The petrographic studies further show that the goethite minerals underwent
alteration and formed bauxite minerals such as gibbsite and boehmite. The presence of gibbsite is
more where the lateralization is gradually more. The pisolitic texture and progressive lateralization
are also observed in the samples. The development of pissolitic textures suggests that they are
further in the process of bauxite formation. This pissolite probably represents bohemite. All these
progressive and intense lateralization and bauxitization processes have led to the leaching of mobile
silicate phases and the concentration of less mobile trace elements along with Fe and Al. The trace
element concentration in the bauxite layers for a few samples shows interesting results, i.e., V (avg.
1120ppm), Zr (avg. 325.85ppm), Ba (avg. 253ppm) and Sc (avg. 93.45ppm). The SEM studies of the
lateritic horizons further (point, line, and bulk analysis) show values for Sc varying between 900 to
1600ppm. The spatial spread of this lateritic horizon is vast; however, the thickness is maximum
up to 2.5m to 3m. These lateritic horizons are well spread over an extensive area, much beyond
the scope of the present study. However, the majority of land falls in agricultural and forest areas.
Hence it would be difficult to propose immediate programs for exploration in these areas, however,
future exploration possibilities cannot be ruled out.
of the Kaimur Group of the Vindhyan Supergroup. Exposed outcrops and cliffs were examined
in detail by section measurement and sedimentary logs were created. The logs are categorized
bed by bed into several facies according to lithology and sedimentary structures. The focus was to
identify the facies succession and to analyze the depositional environment of Dhandraul and Scarp
Sandstone formations.
The Scarp Formation comprises six sub-facies namely sandstone with tidal bundles sub-facies,
planar cross-bedded facies, herringbone cross-bedded facies, ripples with mud crack, parallel
laminated sandstone and trough cross-bed facies. Trough cross bed facies sandstone is thin to
medium bedded, fine-grained immature quartzo-felspathic sandstone having erosional surfaces at
the top. Trough beds with ripple at the top are characteristic of unidirectional flow and indicate a
shallow marine condition, these sub facies are found in association with sandstone having tidal
bundle sub-facies, which is thin to medium bedded, fine-grained sandstone. These sub-facies are
characteristics feature of the tidal-influenced shallow marine environment which is formed by the
periodic activity of flood flow and ebb flow during spring and neap tide. The presence of scour
surfaces at the top of the sandstone having tidal bundles indicates features of high energy condition,
which causes the flute casts under flood flow during the deposition above the fair weather base.
Overall, the Scarp Formation suggests a subtidal to intertidal environment of deposition.
The Dhandraul Sandstone Formation comprises five sub-facies namely, planar cross-bedded
sub-facies, trough cross bed facies, sandstone having tidal bundle facies, and herringbone sandstone
sub-facies. The presence of sandstone having tidal bundle facies with herringbone sub-facies is
typical of the intertidal zone, where neap and spring tide dominates. These sub-facies association is
overlain by sub-facies of medium to coarse-grained planar cross-bed and trough cross-bedded sub-
facies. The grain size of the sediment coarsening sequence, as well as the bed thickening sequence,
suggests shallowing of the basin with a repetitive cycle of bed thickening and thinning. Overall, this
unit shows intertidal to supratidal zone of deposition.
Granulometric analysis of samples from the Dhandraul Sandstone Formation shows that
interbeds of the formation have size < (Φ) 3.75 (Very fine sand) to (Φ) -0.2 (Pebbly sand). The analysis
results show that a very less amount of sediments is also present which is less than < (Φ) 3.75. The
presence of the pebbly nature of grains at the top of the bed either indicates high energy conditions
during the sedimentation to drag out coarser sediments or there should be a break in sedimentation.
17
On the other hand, Scarp Sandstone Formation have sizes from < (Φ) 3.75 (Very fine sand) to (Φ)
0.75 (Coarse sand). The average value of skewness of the sediment shows positive nature indicating
moderate sorting.
The paleocurrent data collected from planar cross beds (28 azimuths) show a mean azimuth of
230o
-355 o whereas trough beds (180 azimuths) range between 250 o
-355 o
. The ripple shows azimuth
between 35o
-340o whereas 17 nos. of parting lineations shows the trend between 260o
-355 o
. It is
inferred that the granite, granodiorite, gneiss, and metasedimentary rocks of the Mahakoshal Group
and Chotanagpur granite–gneiss present in the eastern and southeastern direction may be the
possible source rocks for the Kaimur Group.
Quartzite. The Rewa Group is differentiated into Panna Shale, Lower Rewa Sandstone, Jhiri Shale
and Upper Rewa Sandstone formations. The cyclicity of the thick sequence of arenaceous sediments
interbedded with the argillaceous sediments at different levels indicates the fan delta and braided deposits as the regressive strand of sea changes. The preservation of stratal assemblages in the Rewa
Group of rocks is discernible as the influence of deformation and metamorphism is absent or rare.
The Panna Formation shows three major lithofacies, identified as, thinly bedded siltstone facies (TBSF), silty-shaly facies (SSF), and interbedded sandstone-siltstone facies (ISSF). It is characterized
by an interbedded sequence of very thin to thinly laminated shale and very fine-grained sandstone
with thick beds of siltstone/shale. At places, the shales are calcareous. The Lower Rewa Sandstone
(=Asan Sandstone) is shaly, shelfal succession punctuated by wedge-shaped sandstone bodies are
regressive wedges with varying depositional environments and occurring at multiple stratigraphic
levels. Based on the lithological characteristics the Lower Rewa Sandstone can be subdivided into
three lithofacies i) Sandstone lithofacies ii) Siltstone lithofacies and iii) Shale lithofacies. The sandstone
lithofacies comprises fine to very fine-grained sandstone and sedimentary structures present in it are
suggestive of deposition in intertidal domain.
The overlying Jhiri Shale Formation is classified as (i) Silty-Sandy facies (SStF) and (ii), Silty-
Shaly facies (SShF). The SStF litho-facies comprises an interbedded sequence of silty and sandy
component, where the silty component is more and sequence is very thinly laminated to thinly bedded
in nature, having thickness more than 10-12m with fining upward sequence and the sandstone-
siltstone hetrolithic units are the most common characteristic features signifying intermediate
fluctuation of flow. The silty-shaly facies (SShF) consist primarily of silty and, to a lesser degree,
shaly sequences. This sequence of Jhiri Shale Formation comprises of silty sand in the lower part
followed upward by the silty shaly facies. The silty sandy facies comprise of interbedded sequence
of siltstone and sandstone having swales and hummocky cross-stratification suggesting deposition
in between storm and fair weather wave base under the lower shoreface in transgression. Overall,
this sequence suggests a transitional environment between lower shore to offshore depositional
settings. The Upper Rewa Sandstone has been divided into five facies (i) Liquefied Sandstone (LSt)
(ii) Low Angle Parallel Bedded Sandstone (LAPBSt), (iii) Fine-grained Sandstone (FSt), (iv) Cross-
bedded Sandstone (CBSt), (Large-scale Planar Cross-bedded Sandstone, Herringbone Cross-bedded
Sandstone, Large-scale Trough Cross-bedded Sandstone), (v) Ripple Laminated Silt-mudstone
(RLSiM) which indicates the tide and wave-dominated shoreface environment of deposition.
The Rewa succession, exposed at the Sohagi ghat section, is composed of shale and sandstone
with primary and penecontemporaneous structures, which facilitated facies analysis of these
sediments. The lithological characters, facies associated with them and sedimentary structures
indicate that Panna Formation is of foreshore to shoreface depositional environment. Lower Rewa
Sandstone suggests a tidal flat environment of deposition. Jhiri Formation suggests an outer shelf
15
environment of a deposition while that of the Upper Rewa Sandstone Formation indicates a tide
and wave-dominated shore-face environment of deposition. It is difficult to confirm that cyclicity is caused by a mechanism with a constant time but the regular interval of bedding and cyclic sequences reflects allogenetically controlled periodicity.
Abstract No: T1/P-16
Tectonic Signatures of Passive Margin Settings of the Vindhyan Sequence in Son
Valley, Central India
Hemant Kumar, Ajay Shanker Pandey, Sibabrat Nayak and Sanjiv Kumar
Geological Survey of India, Northern Region, Lucknow
The Vindhyan sedimentary basin of north western and central India is one of the largest
undeformed, Meso-Neoproterozoic basins in the world. During the Proterozoic, the continental crust
witnessed the extensive development of intra-cratonic basins when the thick sedimentary strata
were deposited in these un-metamorphosed basins. The intra-cratonic Vindhyan basin developed
in the central and north-western part of the Indian shield is the largest and thickest Proterozoic
sedimentary succession of India which records the longest depositional histories in terms of its
vastness in space and time. Thus, the study across this basin may help in understanding paleo-
reconstructions, sediment source determination, and the evolution of plate tectonics processes.
The present studies of Vindhyan Supergroup of sediments in the Son Valley sector in the
Central India, reveal that the distinct set of lineaments trending (ENE-WSW) along the Son-Narmada
lineament is responsible for carving out the present configuration of the Vindhyan basin. There
appears to be a series of movements along these geo-sutures which follows the same trend as well
as the N-S, sympathetic faults with attendant cross faults developed along the southern margin of
the basin.
The tectonic discrimination diagrams (SiO2 vs Log K2O/Na 2
O) suggests the passive continental
margin setting for the deposition of the sandstones of Dhandraul Formation, Kaimur Group as well
as Upper Rewa and Lower Rewa Sandstone formations, Rewa Group. The passive margins are
considered to be less deformed but post-continental break-up deformation and associated uplift
have been recorded in the area around Shankergarh area in Prayagraj district, Uttar Pradesh, and
Sohagighat areas in Rewa district, Madhya Pradesh.
Along the Sohagighat section, a reverse fault has been observed along the ENE-WSW direction
with an inclination of approximately 28° towards the south-west. As the thrust faults are commonly
associated with the deformation of layered sediments, especially in passive margins, it signifies
the post-break-up incipient shortening and thickening of the strata, under the action of horizontal
compression which originates due to ridge push. Here the movement of the hanging wall up and
over the footwall material creates the canonical stratigraphic succession, wherein the sedimentary
strata of the Panna Formation are repeated. The density exerts a major control on the vergence of
thrusting and the sedimentary layering provides a pre-existing mechanical anisotropy along which
faults propagate. This provides ideal initial conditions for ramp-flat geometries as evident here.