tectonic of aravalli mountain

1. Dr. Harisingh Gour
Vishwavidyalaya, Sagar
(A Central university)
Presentation
On
TECTONICS OF ARAVALI
FOLD MOUNTAINS
ATHARVA PAWAR
(M.Tech. I year 2018-19)
Submitted to:
Prof. A.K.SHANDILYA
DEPT. OF APPLIED GEOLOGY

2. INTRODUCTION
• Fold Mountains.
• NE-SW Trending Orogenic belt in NW part of INDIA.
• Consists of Aravali Fold Belt and Delhi Fold Belt (Aravali-Delhi
orogenic Belts).
• Age- Proterozoic Eon.
• Primary mechanism.

3. Table 1.1. Succession of the Precambrian Rocks of Rajasthan (Roy et al., 1988)
Supergroup Group and Lithology Age (Ma)
Garnetiferous biotite schists
Raialo Group Marble
Local Basal Garnet
………………………………………………….Unconformity……………………………………………………..
aravali supergroup
Tidi Formation
Machhla-magra Formation
Upper aravali Zawar Formation 1900 -
2500
Udaipur Formation
Shishmagra / Debri Formation
………………………………Unconformity…………………………..
Lower aravali Jhamarkotra Formation
Delwara Formation
…………………………………………………Unconformity………………………………………………………..
Bhilwara Supergroup Hindoli Group
(Pre – aravali) Mangalwar Complex 2500 -
3300
Sandmeta Complex
………………………………………………………Unconformity……………………………………………………
… Banded Gneissic Complex Schists Gneisses and composite
(BGC) gneiss 3300 -
3500
Quartzites

4. BANDED GNEISSIC COMPLEX 3300-3500
• Oldest and Heterogeneous group of rocks.
• Some isolated outcrops
• BGC I : The large NE-SW area around Karera and region
east of Udaipur separated by suite of gneissic rocks
between Nathwara and Ameth.
• BGC II : The large area to the west of the Chittorgarh
contains the Berach Granite.
• BGC III : The scattered BGC outcrops southwest of
Udaipur around Sarara.
• BGC IV : NE-SW trending linear tongue of gneissic rock
occurring as inlier within the Delhis. SW of Beawar.

5. BHILWARA SUPER GROUP 2500-3300
• Surrounded by BGC along extended belt of East of Karera and
West of GBF.
• Covers all rocks groups exposed from Devli to Hindwan.
• Hindoli group is exposed at East and Sandmata region is
exposed at West near Karera.
• Gradual increase in Grade of Metamorphism

6. Aravali Super Group 1900-2500
• The eastern shelf sequence : a. Quartzite association b.
Carbonate association c. Graywacke-phyllite lassociation
• The western suite consists of: a. phyllites and b. Some
quartzites.
• 4 major INTRUSIVES.

7. RAIALO GROUP
• The Raialo group is predominantly calcareous with thin beds
of conglomerate - quartzites at the base.
• The maximum thickness of the succession is about 700
meters.
• The best outcrop area of Raialo occurs north of Udaipur city
and in Nathdwara-Kankoli area.
• The lithology according to Heron is as follows:
granetiferous Biotite schist , Thick crystalline dolomitic marble
,Phyllites – indistinguishable from Aravali phyllites .
• Marble horizon is the most prominent unit.

8. Stratigraphy of Delhi Super Group
Super Group Group Formations Age (ma)
Post Delhi
Malani
Volcanics
600-750
Erinpura
Granite
800-900
Delhi Super
Group
Ajabgarh
Arauli
900-1600
Bharkol
Thana Gazi
Seriska
Kushalgarh
Pratapgarh
Alwar Kankwari
Rajhgarh
Raialo
Divided into 2

10. Stages of Development of Early
Proterozoic Mobile Belts
• 1. The early phase is rifting which is followed by the
bimodal volcanism and pen contemporaneous and
subsequent deposition of arkose and conglomerate.
• 2. The second phase is sedimentation phase which is
represented by accumulation of thick sequence of
greywacke and shale.
• 3. In the third phase, there was compressional
deformation with attendant low-to-moderate-grade
metamorphism. In some areas, the metamorphism was
intense enough to cause differential melting of deeper
rocks and generate granitic melt.

11. Four phases of tectonic evolution
• The tectonic evolution of the Aravali-Delhi orogenic belt can
be divided into four phases:
• 1. Bhilwara Gneissic Complex (~ 2,500 Ma)
• 2. Aravali Orogeny (~ 1,800 Ma)
• 3. Delhi Orogeny (~ 1,100 Ma)
• 4. Post-orogenic evolution (~ 850 – 750 Ma)

12. Deformation in aravali-Delhi
orogeny
• The (F1) produced isoclinal reclined fold with N-S striking axial planer
schistosity and gentle westerly plunging fold axis.
• The folds (F2) are large open to tight upright folds with N-S to NNE-
SSW striking axial planer crenulation cleavage and spaced cleavage
in other rocks.
• The fold (F3) are open recumbent to reclined conjugate minor folds
with gently diping NE-SW striking axial plane. These are upright
conjugate minor folds and kink bands with NNE-SSW and E-W
striking axial plane. The regional structure is huge synclinorium
trending NE-SW. The synclinorium extend from Delhi in the NE to
Gulf of Cambay in the SW with constriction in the central part near
Ajmer- Marwar where the synclinorim is represented two synclines.
• The (F4) Fold (Delhi phase III) is represented by a set of open minor
folds and puckers with vertical axial plane strike vary from ENE-WSW
through E-W to ESE-WNW.

13. Phases of Deformations
Deformation Fold Trend Lineation
D1 F1 N-S L1
D2 F2 NNE-SSW L2
D3 F3 NE-SW L3
D4 F4 E-W L4

14. MajorFour
generations
ofFoldingin
Mountains.
Diagrammatic representation of the sequence of deformational phases and fold
styles in the Precambrian rocks of Rajasthan,NW India (based on Naha and others,
1967, 1984; Mukhopadhyay and Dasgupta, 1978; Roy, 1988; Srivastava et al., 1995

15. EvolutionofAravaliDelhiorogenybelt

16. Evolution of the Aravali Mobile
Belt is ascribed to plate tectonics
(after Sinha-Roy 1988)

17. Association with
supercontinent cycles

18. CrosssectionsillustratethestructureoftheAravalimountains(basedonSharma
1995)

19. Major lineaments

21. Concept no. 03
• “To the large degree, the earth’s
surface posses relief because
geological process operate at
diferent places”- W.M.DAVIS.
Principle of Geomorphology.
Anticline eroded

23. BIBLOGRAPHY
• Geological and Geophysical manifestations from North West India,
Gupta and Bose(2000)
• Geochronology of Precambrian rocks of Rajasthan, Naha et al (1984)
• K.S. Valdiya: The making of India
• Ram S. Sharma: Cratons and Fold Belts of India (2010)
• S. M. Naqvi & J.J.W. Rogers (1987): Precambrian geology of India
• [Society of Earth Scientists Series] M.E.A. Mondal - Geological
Evolution of the Precambrian Indian Shield (2019, Springer
International Publishing)
• The geology of Central Rajputana, Heron(1953)
• K.S. Valdiya: The making of India
• Principles of Geomorphology – W.D.Thornbury
• Google Images.
THANK YOU