9atharva pawar
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This presentation provides an overview of the tectonics of the Aravali fold mountains in northwest India. The key points are: 1. The Aravali fold belt trends northeast-southwest and consists of folded Proterozoic sedimentary rocks ranging from 3,300-1,900 million years old. 2. The belt has undergone four phases of deformation and folding between 1,800-1,100 million years ago during the Aravali and Delhi orogenies. 3. Stratigraphy of the region includes the Banded Gneissic Complex at the base, overlain by the Bhilwara Supergroup and Aravali Supergroup, with the Delhi Supergroup
![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](https://image.slidesharecdn.com/9atharvapawar-181209032700/85/9atharva-pawar-23-320.jpg)
9atharva pawar
- 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
- 16. Evolution of the Aravali Mobile Belt is ascribed to plate tectonics (after Sinha-Roy 1988)
- 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