Geological framework of Peninsular
India showing the major Archaean
cratonic blocks, Proterozoic belts
and Deccan flood basalt cover.
The inset shows the major
Palaeoproterozoic sutures in
Peninsular India classified here as
the Eastern India, Central India and
Western India Suture. The Southern
Granulite Terrain was mostly
assembled during late
Neoproterozoic–Cambrian during
the final assembly of the Gondwana
supercontinent, although suspect
Palaeoproterozoic terrains and
basement rocks occur.
ARAVALLI CRATON
Introduction
Aravalli craton occupies NW part of the Indian
shield covering an area of over 1 lakh sqkm
It consists of Mewar craton in the east and
Marwar craton in the west
Aravalli craton is bounded to the east by Great
Boundary Fault, to the north by Indo-Gangetic
alluvium, to the south by Son-Narmada-Tapti
lineament and to the west by sands of Thar
Desert.
It predominantly consists of quartzites, marbles,
pelites (fine-grained sedimentary rock, i.e. mudstone or siltstone),
greywackes and volcanics that are exposed in the
Proterozoic Aravalli-Delhi orogen
It is distinguished by the occurrence of largest
felsic province (Malani Igneous Suite) of India, 3rd
largest felsic province of the world
Aravalli Craton
Aravalli and Delhi fold belts are collectively known as the Aravalli-Delhi orogenic belt, which is about
700 km long and formed in Proterozoic. The collision between the Bundelkhand Craton and the Marwar
Craton is believed to be the primary mechanism for the development of the fold belt.
The base is Mewar Gneiss Complex and is overlain by the rocks of Aravalli Supergroup and Delhi
Supergroup
ARAVALLI AND DELHI FOLD BELTS
In western India, a 700 km long mountain range known as Aravalli Mountain contains record of two
orogenic movements,
The first Aravalli orogeny, early Proterozoic in age and affecting the rocks deposited in an epicontinental
sea with volcanics at the base and clastics at the top.
The second orogeny is Middle Proterozoic in age affects both the older Aravalli rocks, already deformed
and another group called Delhi that is mostly volcanic, carbonates and some clastics.
Though the Delhi rocks occupy the entire mountain range, the name derives from the older rocks.
The rocks of the Aravalli Supergroup show only greenschist facies of metamorphic grade while those of
the Delhi Supergroup are highly metamorphosed to amphiblite assemblages with sporadic occurrences of
granulite facies of rocks as at Sandmata.
ECONOMIC DEPOSITS: The major economic deposits are: Pb-Zn deposits (Agucha, Zawar etc),
Stromatolitic phosphorite, Gypsum, Marble (Macrana), BIF Mica (Jagat Group), Copper (Khetri), Tungsten
(Degana, Balda and Sewariya-Govindgarh areas).
Main Components:
Archean Mewar Gneiss (a.k.a. BGC – Banded Gnessic Complex/Bhilwara
Supergroup) with Ancient Supracrustal Enclaves
Bhilwara Supergroup (Hindoli group, Mangalwar complex and Sandmata
Complex)
Mineralized Supracrustal Belts (Rajpura-Dariba, Pur- Banera etc)
Palaeoproterozoic Aravalli Fold Belt
Mesoproterozoic Delhi Fold Belt
Neoproterozoic Basins (Sirohi, Sindreth, Punagarh)
Neoproterozoic Malani Igneous Suite
Neoproterozoic Marwar Basins
Crustal Scale Lineaments:
There are some major crustal lineaments in Aravalli craton, which separates this in few units.
These are
Great Boundary Fault – bounding Vindhyan Basin to the west and Hindoli Basin to the east
Banas lineament or Jahazpur Thrust that separates Hindoli belt from Mangalwar Complex
in the north and Mewar Gneiss in south.
Delwara Lineament – metamorphic-migmatitic contact between Mangalwar and Sandmata
complexes,
Kaliguman Lineament that separates Delhi fold belt from Sandmata Complex in the north
and Aravalli fold belt in the south.
Rikhabdev Lineament enclosing an ultramafic-mafic belt between shallow self and deep
water facies Aravalli fold belt,
Phulad Lineament marked the tectonic boundary between Mewar and Marwar cratons of
the composite Aravalli Craton.
Four phases of tectonic evolution
The tectonic evolution of the Aravalli-Delhi orogenic belt can be divided into four phases:
4. Post-orogenic evolution (~ 850 – 750 Ma)
3. Delhi Orogeny (~ 1,100 Ma)
2. Aravalli Orogeny (~ 1,800 Ma)
1. Bhilwara Gneissic Complex (~ 2,500 Ma)
Two phases of rifting, sedimentation, collision and suturing were documented in the tectonic
evolution of the Aravalli-Delhi orogenic belt.
During Proterozoic, N-S convergence between the Bundelkhand and Bhandara cratons at the
Satpura Mobile Belt, and E-W convergence between the Bundelkhand and Marwar cratons at the
Aravalli-Delhi orogenic belt have synchronously occurred in India. This resulted in an overall
resultant force of NE-SW convergence of the Aravalli-Delhi orogenic belt, and also led to the
arcuate shape of its convergent zone.
7. Marwar Supergroup
6. Malani Group
5. Erinpura Granite
4. Sirohi Group
3. Delhi Supergroup
2. Aravalli Supergroup
1. Archaean Basement (BGC)
General geological formations
Post Delhi orogeny Marwar Supergroup, Malani Group, Erinpura Granite, Sirohi Group
Ajabgarh Group (=Kumbhalgarh Group) Carbonate, mafic volcanic and argillaceous rocks
Delhi Supergroup Alwar Group (= Gogunda Group) Arenaceous and mafic volcanic rocks
Raialo Group Mafic volcanic and calcareous rocks
Jharol Group Turbidite facies and argillaceous rocks
Aravalli Supergroup Debari Group
Carbonates, quartzite, and pelitic rocks
Delwara Group
Archean basement Banded Gneissic Complex (BGC) Schists, gneisses and composite gneiss Quartzites
Fig : Stratigraphy Scheme of Aravalli Supergroup
Post Delhi Neoproterozoic stratigraphy of Western Rajasthan
Mewar Gneiss:
BGC, defined by Heron(1953), grey gneisses, migmatites and granitoids of the Mewar region as
Banded Gneissic Complex(BGC)
This BGC extremely diverse in terms of rock association, metamorphism and geological antiquity.
BGC as the oldest stratigraphic unit of Rajasthan.
The three principal components of Mewar Gneiss are:
I. Basement TTG gneisses least affected by later deformation and metamorphism
II. Basement granitoids intruding the TTG gneisses (e.g Untala and Gingla granites) and
III.Basement granitoids occurring as inliers within the Aravalli Fold Belt (e.g Sarara, Mando and Ahar
River granites).
There are some other tectono-stratigraphic unit, related to BGC, occur within the Aravalli
craton.
The division of BGC, renamed as Bhilwara Supergroup.
Hindoli Group:
Hindoli belt is covered by Deccan trap of Malwa plateau in the south
Turbidites, greywacke, phyllites & minor volcanics.
Both faulted and unconformable contact with Vindhyan.
Locally faulted contact with gneissic complex
Variously equated with Gwalior group of Bundelkhand craton
• Berach Granite
• Mangalwar complex
• Sandmata complex
Aravalli Supergroup:
Aravalli Supergroup:
Fig : Geological map of Aravalli Fold belt
Aravalli Supergroup:
Delwara Group: has an area over 300km with an average width of about 500m.The basement
rock is orthoquartzite which is overlain by volcanic conglomerate (volcanic unit)
Delbari Group: it overlain the Delwara Group consists of a thick horizon of petromict
conglomerate, pebble arkose and feldspatic quartzite. The conglomerate has a maximum
thickness of 2500m near Dabari
Udaipur Group: consist of thick accumulation of greywacke-phyllite intercalated with
chemogenic and biogenic rocks. The greywacke-phyllite is overlain by dolomite associated
with carbonaceous phyllite and quartzite.
Jharol Group: consists of thick sequence of carbonate-free phyllite and arenite (as distal
turbidites) has an area of 200km with a width of 40km
Lunavada Group: It occupy the polygonal area in the south of the Aravalli orogen. The bulk
of the group consists of greywacke-phyllite with associated quartz arenite.
Champaner Group: occurs as rectangular outcrop and consists of subgreywacke, siliceous
phyllite, pelitic schist, quartzite and petromict conglomerate. It is folded into an
anticlinorium plunging to the west The stratigraphy status is unclear because it is separated
by the main fold belt.
Mesoproterozoic Delhi Fold Belt
The Proterozoic Delhi Supergroup occupies three
NE-SW trending linear belts in the northeastern
part of the Aravalli mountain range, where its 10
km thick volcano-sedimentary sequence is
classified into unconformity-based three groups:
the Raialo, the Alwar, and the Ajabgarh
Delhi Supergroup:
North Delhi Fold Belt:
Ajabgarh Group: Carbonaceous phyllites in the lower part and
ferruginous quartzite in upper part
Alwar Group: conglomerate, orthoquarzite, feldspahic arkose
Raialo Group: Besal conglomerate, pebbly quartzite
Khetri Basin: Important for Copper mineralisation.
North Khetri Basin
South Khetri Basin
South Delhi Fold Belt
Bhim Group: Pelitic to semi-pelitic schist, calc-silicates
Rajgarh Group: Cross-bedded quartzite, pelitic schist and calc-
gneisses
Sendra Group: Metabasalt, marble,suarkose, semipalite and
quartzite
Barotiya Group: Barr conglomerate, micaschist, impure marble
Basantgarh Group: Metabasalt, calc-schist, metapelite, basic
volcanic breccia, metagabbro.
Fig : Division of NDFB and SDFB
Delhi Supergroup:
North Delhi Fold Belt:
Ajabgarh Group: Carbonaceous phyllites in the lower part and
ferruginous quartzite in upper part
Alwar Group: conglomerate, orthoquarzite, feldspahic arkose
Raialo Group: Besal conglomerate, pebbly quartzite
Khetri Basin: Important for Copper mineralisation.
North Khetri Basin
South Khetri Basin
South Delhi Fold Belt
Bhim Group: Pelitic to semi-pelitic schist, calc-silicates
Rajgarh Group: Cross-bedded quartzite, pelitic schist and calc-
gneisses
Sendra Group: Metabasalt, marble,suarkose, semipalite and
quartzite
Barotiya Group: Barr conglomerate, micaschist, impure marble
Basantgarh Group: Metabasalt, calc-schist, metapelite, basic
volcanic breccia, metagabbro.
Fig : Division of NDFB and SDFB
Neoproterozoic Basins:
Sirohi Group
Sindreth Group
Punagarh Group
Granite Intrusions:
1. Erinpura granite:
2. Balda granite
3. Degana granite
4. Godhra granite
5. Lamprophyre
Neoproterozoic Basins (Malani Igneous Suite)
MIS is divided into three phases of igneous
activity based on field relations, mode and
type of magmatism as well as texture and
composition of rock types.
3.Dyke swarms: Gabbro, dolerite, granite,
aptite, rhyolite, andesite, trachyte,
porphyry etc.
2. Granitoids : Malani, Jalor and Siwana
granites
1. Bimodal volcanics: Rhyolite, rhyodacite,
dacite and trachyte, basalt and trachy-
andesite
Neoproterozoic Marwar Basins:
Tectonic Stratigraphic table of evolution of Aravalli craton
Tectonic evolution of Aravalli craton
Mineralised Supracrustal Belts
Jahazpur belt: The western sub-belt is the type area for
jahazpur group that contains basal conglomerate and gritty
quartzite, grey phyllite, dolomitic with BIF, rhyolite, quartz
arenite and basic volcanics
Sawar Belt: It contains basal cong-lomerate, Quartzite,
dolomitic marble, calc-silicate rock and carbonaceous phyllite.
Chalcopyrite-pyrrhotite-galena-sphalerite ores are localised in
this belt in favourable structures
Pur-Banera Belt: Comprising basal cong-lomerate, BIF,
dolomitic marble, chert, etc.,. BIF and carbonates host strata-
bound zinc-lead-copper mineralization
Rajpura-Dariba Belt: Basal conglomerate, quartzite, dolomitic
marble, calc-silicate rock, pelitic schist, Syn-sedimentary Pb-
Zn-Cu prominent, Ag mineralization
Rampura-Agucha Belt: Pb-Zn deposit metasedimentary
sequence of pelitic gneiss,basaltic and andesitic amphibolite.
Fig : Geological map and cross section of Jahazpur belt
Economic deposits
The major economic deposits are:
• Pb-Zn deposits (Zawar)
• Gypsum
• Marble
• BIF
• Mica (Jagat group)
• Copper (Khetri)
• Tungsten (Degana, Balda and Sewariya- Govindgarh areas)
Conclusion:
Thus we can conclude that the Aravalli Craton is the one of the significant Precambrian terrain with
the evidences of several generations of deformation, metamorphism and complex tectonism
related to the evolution of Indian plate through geological time.
A common feature of these cratonic regions is the occurrence of greenstone-gneiss association, as
found in other Archean cratons of the world.
The Indian shield is made up of a mosaic of Precambrian metamorphic terrains that exhibit low to
high grade crystalline rocks in the age of 3.6-2.6Ga.
Delhi Supergroup:
