BUNDELKHAND CRATON PPT.pptx

ABOUT BUNDELKHAND CRATON

1. A Seminar On BUNDELKHAND CRATON Jiwaji University, Gwalior Under The Guidance By :- Submitted By :- Dr. P.K.Jain Chinmay Kumar Pradhan S.O.S Earth Science M.Sc. 1 st Year

2. CONTENT 1.INTRODUCTION 2.MAIN COMPONENTS OF THE CRATON SUPRACRUSTALS AND GNEISSES BUNDELKHAND GRANITE AND QUARTZ REEFS MAFIC DYKE SWARMS 3.TECTONIC EVOLUTION 4.SHEAR ZONES 5.SIGNIFICANCE 6.CONCLUSION 7.BIBLIOGRAPHY

3. INTRODUCTION CRATON: It is that part of the earths continental crust which has attained stability and least affected by deformation during the later periods. There are five cratons in the Indian shield They are: 1.Dharwar craton 2.Baster craton 3.Singhbhum craton 4.Bundelkhand craton 5.Aravali craton

4. " HISTORY OF BUNDELKHAND CRATON Bundelkhand craton named for the fifteenth century kingdom of Bundelkhand .it is a triangular region having semi-circular sides and Bundelkhand craton is one of the Archean craton in the Indian shield.

5. Bundelkhand craton is exposed over 26000 sq k.m and is bound by the son normada lineament in the south.it is separated from the satpura mobile belt in the south and aravali craton in the west by the Proterozoic Vindhyan basin and the northen part is overlain by the indo-gangetic alluvium It located between lat. 240 30' N and 260 30' N and long. 770 30' E and 810 50'E Geological location of Bundelkhand craton

6. MAIN COMPONENTS OF THE CRATON Enclave suite of supracrustal rocks with in orthogneisses . Bundelkhand granite associated with quartz reefs and rare felsic volcanic. Mafic dyke swarms.

7. Enclave suite of supracrustal rocks within orthogneisses Two prominent east west trending belts of enclaves are noticed – 1.northern belt( karera to kabrai ) 2.southern belt( madaura to baraitha ) 3.otherlinear enclve are noticed at near panna kalinjer .these belts have regional trend of E-W with northerly dips.

8. Enclaves essentially consist of 1. Ultramafic rocks - 1.(peridotite + dunite +pyroxenite +gabbro ) 2.Wide spread in southern belt 3. mg and cr rich gabbro are seen in northern belt. 2. Meta basic rock - 1.abundant in both belt 2.schistose metabasalt + amphibolites 3. BIF - 1.wide spread around Girar , Baraitha , Babina . 2.compositionally banded quartz-magnetite , banded magnetite-grunerite

9. Continue…. Meta pelites : 1.consists of garnet, biotite, sillimanite. 2.occure as schists. 3.occure near Mauranipur .

10. A)Amphibolite and enclave with in TTG b)Tabular pillow basalt c)BIF d)Contact between Amphibolite and BIF

11. GNEISSES Grey and pink banded to streaky gneisses occur as silvers , rafts and narrow belts with in vast area of younger Bundelkhand granite . In the stomatic gneisses,biotite and hornbland bearing granodiorites melanosomes occure as bandeds or rafts in leucosomes . Gneisses are best exposed at south of babina and yield age of 2500-2550 ma. The oldest gneissic component ; kuraicha 3.29 Ga The youngest gnessic component ; panchwara 2.9 Ga

12. 1.Bundelkhand Granite associated with Quartz Reefs and rare Felsic volcanic 1.Cover most of the cratonic area.(Bundelkhand granite) 2.Batholithic nature. 3.There are four phases of granite- (geochemical study) (a) Horn blende granodiorite. (b) Porphyritic biotite granite. (c) Coarse porphyritic granite. (d) leuco granite.

13. 1(A)RARE Felsic volcanics 1.Rhyolite to rhyodacite in composition. 2.Occurs as sills . 3.These rocks are associated with the granites at many places such as Mahoba , Bansi and simra near prithipur . 4.They occur as grey to pink, fine to coarse grained and porphyritic felsic rocks.

14. 1(B)QUARTZ REEFS 1.It having general trend NE-SW. 2.It having dimension ,35-40 km length and 50-60m width . 3.Associted with pyrite, specular hematite, chlorite, chalcopyrite. 4.The sulphides in quartz veins indicates extensive hydrothermal activity in Bundelkhand granite . 5.it indicates end stage of granitic plutonism.

15. MAFIC DYKE SWARMS 1.Having trend NW-SE 2.Three Generation of dyke last one is related to deccan trap. 3.Dimension:Few tens of meter lenghth and 50 mtr wide. 4.introduce both granite and quartz reefs . 5.composition: Dolerite and Gabbros 6.Age: 180 Ma

16. TECTONIC EVOLUTION Bundelkhand and Aravalli cratons were traditionally regarded as interlinked, with the Bearch granite of Aravalli craton being considered as the equivalent of Bundelkhand granite Geochemical and Geochronological similarities have reinforced this comparison. The separation of two cratons with the evolution of Hindoli and Mahakoshal belts at the cratonic margin, was followed by the evolution of Vindhyan basin. Bundelkhand craton witnessed N-S compression induced deformation , metamorphism and emplacement of TTG gneisses produced by the partial melting of a garnet amphibolite parental source at 3000-3300Ma. Widespread collision-related arc magmatism represented by Bundelkhand granite commenced probably at 2700Ma and culminated at 2500Ma.

17. SHEAR ZONES IN BUNDELKHAND CRATON The region is characterized by the presence of dominantly three types of shear zones: E-W, NE-SW and NW-SE. The E-W trending, vertical shear zones constitute the subject matter of the present study and the areas where these shear zones are exposed have been shown. It may be noted that in addition to the E-W shear zones shown in this map, there are many such shears of relatively smaller extent that could not be shown because of the scale of the map, however, were studied because of their typical features, e.g. Jhankri , Kuraicha , Roni, etc

18. Field photographs showing the typical occurrence of the vertical shear zones in the Bundelkhand terrain. The rocks are mylonites . (a) Near Shivgarh , (b) At Dhaura , (c) Near Koti , about 6 km SE of Babina , (d) North of Pura, about 5 km NW of Sukumwa Dam.

19. SOME FACTS ABOUT BUNDELKHAND CRATON The Precambrian age Bundelkhand massif is composite body comprised mainly of felsic igneous rocks. The Geochemistry of the massif shows calc –alkaline to alkaline affinity and points to collision- related magmatism. The pattern closely resembles that of continental margin sierra naveda -type batholiths and the subduction – related Benghnema batholith Indian plate have accreted from several micro-plates during Precambrians time ,with consequent emplacement of collision –Bundelkhand craton has formed . The area mainly comprises tonalite – tronjemite-granodorite (TTG)gneisses, amphibolites,banded iron formation, komatiitic basalts,metaperidotite,calc - sillicatesrocks,corundum -bearing ,quartz-sericite schists, fuchsite quartzite and giant quartz veins,mafic dykes and some noritic instrusion

20. SIGNIFICANCE The geochronological and geochemical studies on mafic dikes and intrusions provide evidence on the extensional processes that occurred in the craton, as a great bearing on the Paleoproterozoic evolution of the Bundelkhand craton. By the study of Bundelkhand craton we found difference type of economical mineral ex- 1.Diaspore – Lalitpur,Jhansi,Mohoba 2.Silica or glass sand- chitrokoot 3.clay-Chatarpur

21. CONCLUSION Bundelkhand Craton is one of the Archean cratons in the Indian shield. It is exposed over 26,000 sq. km and is bound by the Son Narmada lineament in the south, the Great Boundary Fault in the west, and probably the Lesser Himalaya in the north. The eastern, western, and southern margins of the Bundelkhand craton are covered by the Proterozoic Vindhyan Supergroup and the northern part is overlain by the Indo- Gangetic alluvium. The main components of the cratons are - i . Enclave suite of supracrustal rocks within orthogneisses. ii. Bundelkhand granite with associated quartz reefs and rare felsic volcanic. iii.Mafic dyke swarms. Three types of shear zones are noticed in Bundelkhand Craton i . E-W shear zone ii. NE-SW shear zone iii. NW-SE shear zone

22. BIBLIOGRAPHY Geology of India by M.Ramakrishnan and R. Vaidyanathan Crustal evolution of Bundelkhand craton By Dr.Pradip kumar singh

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