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  1. Guided by Dr.M .SHANKARA Professor D O S In EARTH SCIENCE Manasagangotri Mysore Presented by MARUTHI N.E 3rd semester Applied Geology
  2. CONTENTS  INTRODUCTION  Bundelkhand craton  Main components of the craton  i. Supracrustls & Gneisses  ii. Bundelkhand Granite  and Quartz reefs  iii. Mafic dyke swarms  Tectonic evolution  Shear zones  Conclusion  Reference
  3. INTRODUCTION It is that part of the earths continental crust which has attained stability and was least affected by deformation during the later periods. There are five cratons in the Indian shield . They are : 1) Dharwar Craton 2) Bastar Craton 3) Singhbhum Craton 4) Bundelkhand Craton 5) Aravalli craton what is a Craton?
  4. Bundelkhand craton named for the fifteenth century kingdom of Bundelkhand is a triangular region having semi- circular sides and 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. Bundelkhand craton is separated from the Satpura mobile belt in the south and the Aravalli craton in the west by the proterozoic vindhyan besin and the northern 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 .
  5. 1) Enclave suite of supracrustal rocks within orthogneisses. 2) Bundelkhand granite associated with quartz reefs and rare felsic volcanic. 3) Mafic dyke swarms
  6. Supracrustals Two prominent east-west trending belts of enclave are noticed i) Northern belt extending from karera to kabrai, kuraicha Jhansi Mauranipur and Mahoba ii) Southern belt from to Baraitha through Girar. otherlinear enclave are noticed at near panna and kalinjer. These belts have a regional trend of E-W with northerly dips. The enclaves consist essentially of BIF with amphibolites, ultramafics and minor quartzite, metapelite and marble. Ultramafic rocks are mainly peridotites dunites pyroxenites and gabbros closely associated with metabasic rocks and BIF.
  7. Cont…… They form melanosomes of migmatites and occur as discrete patches in granites as near Jhansi and karera.  Metabasic rocks are the most abundant among the enclaves in the southern and northern belts. They range in composition from schistose metabasalts to low grade amphibolites some of which show primary volcanic structures.  Banded Iron Formation is the most conspicuous in the enclave suite and is widespread around Girar and Baraitha. • Carbonate rocks and quartzite's also occur as scattered lens and bands. • Metapelites are rather rare, and when present consist of garnet, biotite and sillimanite.
  8. • Grey and pink banded (stromatic) to streaky gneisses occur as slivers, rafts and narrow belt within vast areas of younger Bundelkhand granite. In the stromatic gneisses, biotite and hornblende bearing granodiorite melanosomes occur as bandeds or rafts in leucosomes. • A basic enclave in the gneiss at mahoba also gave an age of 3250 Ma • The oldest gneissic component; kuraicha 3.29 Ga • The youngest gneissic component; Panchwara 2.5 Ga
  9. The vast country of Bundelkhand granite represents a larg plutonic complex of batholithic dimension. Three types Granite; i)Coarse grained porphyritic granite. ii)Medium grained porphyritic granite. iii) Leucogranite, Felsic volcanic rocks: these rocks are associated with the granites at many places such as mahoba, bansi, and simra near prithipur they occur as grey to pink , fine to coarse grained and porphyritic felsic rocks.
  10. The emplacement of NE-SW trending giant quartz reefs along brittle shear zones probably marks the end stage hydrothermal activity related to granitic plutonism.
  11. A NW-SE trending swarm of Mafic dykes is a characteristic feature of Bundelkhand craton some of dykes have ENE trend, like the prominent mahoba dyke .The geometry of the main dyke swarms is attributed to E-W shearing stress, developed after cratonisation.
  12. • 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.
  13.  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.
  14. 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.
  15. A & B- Ultramylonite showing high degree of grain-size reduction because of dynamic recrystallization Cataclasite showing angular grains set in a fine grained matrix.
  16. CONCLUSIONS • 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
  17. Geology of India by M.Ramakrishnan and R. Vaidyanathan. Published: 2008 pg:149-260  WEB: