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1. STRATIGRAPHY Topic = GONDWANA SUPERGROUP SUBMITTED TO- DR. PRAMOD ANTHWAL SUBMIITED BY- NAME=SONAKSHI NEGI M.SC. 2 ND SEM ( GEOLOGY)

2. INTRODUCTION The term gondwana was coined by medlicott (1872). This supergroup has been named after the gond kingdom of madhya pradesh . The age of gondwana super group upper carboniferous to lower cretaceous. Structure – the gondwana rocks are not folded,only tilted. Faults are common.the gondwana basins are mostly bounded by faults. Distrinution - along the son- damodar valley - “ the M ahanadi valley - along the G odavari – wardha valley.

3. LITHOLOGY The total thickness of gondwana super group is 6000-7000 m. Succession of mainly fluviatile and lacustrine deposits. glacial deposit occurs at the base. and the intercalations of the fossiliferous . Chief rock= sandstones, shales , clays, conglomerates, and coal seams. Upper gondwana succession contains about 600 m thick lavaflows of basalt.

4. Classification of gondwana super group Two fold classification- by W.T. blanford , divided into lower and upper gondwana ,characterised by the glassopteris and ptilophyllum . 2) Three fold classification = supported by o. feistmantel and D.N.wadia . On the basic of difference in lithology .

5. Succesion of gondwana supergroup

6. LOWER GONDWANA FORMATION TALCHIR GROUP - rest unconformably over Archeans or Precambrian rocks. Thickness – 170-350 m. Chief rock types- boulder beds, shales , and sanstones . The boulder bed which forms the base of the talchir group, is glacial origin. Rikba – sandstones undecomposed feldspars, cold climate . Age – up.carboniferous to lower permian .

7. Damuda group- this group is named after the damodar river. Thickness – 2000 m. The damuda group has been subdivided into four formation : 1) karharbari formation -it is basal unit of damuda group. Thickness – 60-120m. Thick succession of sandstones, grits and same coal seams.

8. BARAKAR FORMATION = is named after the barakar river. It composed of sandstones, shales , grits and conglomerate. With many coal seams. thickness=800M The barakar formation is the most important coal bearing formation of lower gondwana succession. In the jharia coal fied this formation contains about 25 % coal seams. Both the karharbari and barakar formation are of lower permian age.

9. Barren measures fomation Thickness = 500 m The age of this formation is about middle permian . It composed sandstones and ironstone shale.

10. 4) Raniganj formation= Composed of about 1000m thick sucession of sandstones shales ,coal seams. Age of raniganj formation is upper permian . In this formation there are 9 coal seams in the raniganj coal field, and 7 coal seams in jharia coal field.

11. Panchet Group It is composed of about 700 m thick succession brown sandstone and shales . The rock of panchet group have a rich assemblage of plant fossils. 1) glossopteris 2) schizoneura 3) pecopteris Age of panchet group is lower Triassic.

12. UPPER GONDWANA FORMATION Mahadeva group = this group has been named after the mahadeva hills near pachmari in the satpura area of MP. 1) PACHMARI FORMATION = this formation is best developed around pachmari in MP. it consists of about 800 m thick red sandstone and clays. Age of pachmari formation is lower to middle triassic . 2) MALERI FORMATION well developed near Hydrabad in Andhra pradesh . Upper triassic age . It consists of red clays with sandstones.

13. Rajmahal group 1) Rajmahal formation Thickness =650m It is made up of extensive lawaflows of basic composition called tha rajmahal traps. 2 ) kota formation Thickness 650 m Composed mainly of sandstones and grits with some bands of clay. Age = lower to middle jurassic

14. JABALPUR GROUP It is well developed in the satpura region in central india . Rests unconformably over mahadeva group. Made of massive sandstone,conglomerates ,white clays. Rich in plant fossils. Divided on the basis of plant fossils Chaugon formation = Taeniopteris , nilssonia,Dictyozamites , etc. Jabalpur formation= ptilophyllum otozamites , brachyphylum , etc. The chaugon and jabalpur formation are of middle to upper jurassic age. Umia formation = the topmost formation of the gondwana succession is called the umia . Well develop in the cutch area in gujrat . It is composed of about 100 m thick succession of sandstone, shales .

15. FOSSILS Upper gondwana fosslis = Ptyllophyllum William sonia Nillssonia Auto zamytes Dictyzamytes Lower gondwana fossils= Glassopteris Gangamopteris Vertibraria Shizoneura Phylothea

16. Economic minerals 1) Coal = the barakhar and raniganj formation of the damuda group constitute the most important coal bearing rock formation. All of the gondwana coal is of bituminous variety. 2) Iron ore = about 760 m thick ferruginous shales . 3) clay = the clays of various types are found in abundance in the gondwana rocks. 4) buliding stone = the gondwana sandstone is generally of inferior quality.

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