Status of Kamthi Formation : lithological and palaeobotanical evidences Suresh C. Srivastava & Neerja ]ha Srivastava Suresh C & Jha N 1997. Status of Kamthi Formation: lithological and palaeobotanical evidences. Palaeobotanist 46 0,2) : 88-96. On the basis of lithological, palynological and megafloral data the status of Kamthi Formation has been reviewed. Hitheno known Kamthi Formation which was said to be a time-transgressive unit (Permian-Triassic) actually represents a Triassic sequence overlying Permian sediments equivalent to Raniganj Formation. Presence of Permian taxa, viz., Glossopteris, Ve11ebraria and Pbyllotbeca in red claystone, ferruginous sandstone/shale unit (-Upper Member, Kamthi Formation) represent only the continuations of Permian taxa into the Triassic. Key-words - Lithology, Megafossils, Palynofossils, Karmhi Formation, Panchet Formation, Triassic, India. Suresb C. Srivastava & Neerjajba, Birbal Sabni Institute ofPalaeobotany, 53 University Road, Lucknow 226 007, India. wm ~ m-r-~ qit mfir : ~r~~14 ~ q{IGHWrnQi lIlmJT ~~~~m ~m~ ~, q{llIiOlfcjCfl~ j{lQOj*4R!>5llffi4 ~cf;3lJl:TR'CR~m-~qit~~~qitliftl ~ ~ ~ (~-~) ~ ~ ~~ ~~~ \ill 3fIft Qcn ern q-ym it cf; '3i1l{ 'CflT ~ ~~ ~~ ~ffill!/lq;1 ~ ~~CflfcIitqit~~~ ~~ IC1T~TQR~, ~tl it CflfcIit qit 0!/CRf mm tl THE name 'Kamthi' was introduced by Blanford to Raniganj-Panchet Formation of Damodar Basin, (1868) for a group of rocks exposed near military Bijori Formation of Satpura Basin, Pali Formation of station 'Kamptee' close to Nagpur. The 'Kamthi South Rewa Basin and Pachhwara Formation of Group' of rocks as described by Blanford (1877, p. Rajmahal Basin. In coastal tract ofGodavari Graben 299) sensu stricto are composed of"grits, sometimes Kamthi Formation was earlier referred as Chintalpudi very hard at other times soft and frequently sandstone. ferruginous. These are often intersected by bands in The name 'Kamthi' has been used in different which the quartz and carbon are cemented together sense by different authors in different basins. Initially by peroxide of iron. The group also contains there was no intention to retain the name. It was sandstone of various kinds, amongst which fine­ thought that evidence might be accumulated soon to grained slightly micaceous bed, white in colour with identify the rocks as the member of group already blotches and irregular streaks of red are abundant established in Damodar Basin (Hughes, 1877, p. 67). and the fine homogeneous argillaceous rocks which On the basis of fossil plants the Kamthi beds were for want of better name called a compact shale, correlated with Damudas while the mineral characters yellow below the surface, but becoming deep red ofKamthi were different with that ofboth Iron Stone when exposed". Similar rocks were later identified in Shales and the Raniganj as this was devoid of iron Wardha-Godavari Valley in Maharashtra and Andhra stone shales and coal both. Thus the name 'Kamthi' Pradesh and in Mahanadi Valley, Orissa. In the latter continued to exist on account of its characteristic area it was earlier known as Hingir Formation. lithological attributes and its age was debated on the Kamthi Formation is generally considered equivalent basis of palaeobotanical contents till recently. Now SRlVASTAVA & JHA- STATUS OF KAMTHI FORMATION 89 Table l---Status of KamtW Formation In Godavari Graben Sengupta Raja Rao King Raiverman el at. Kuny el at. Pandey Ramanamurty & (881) (970) (982) (985) (988) Jha & Srivastava (988) Madhusudan Rao (996) (987) (996) . K K Upper Upper Upper Member K KUDUREPALW K K KAMTHI Upper A Member K A Member (- Supra-Parr:::hetl Member CHrNTALPUDI M KAMTHI A Middle M Mahadeva) A A T KAM· M Member T H T A MANER Lower THI Lower I H Lower Member Member Member H M Middle M I (- Panchet) I Member I KHANPUR Litho- Litho- R M N zone-4 facies-2 A IRON STONE T T F Upper Upper N SHALE JAlPURAM R Coal Litho- I T A Measures RANIGANJ H Lower H zone-3 Litho- G Member facies-l A iPOTAMADUGU/ K Litho- H N Lower I I BALHARSHAH A zone-2 J M T I BARAKAR S BARREN H Litho- BARREN MEASURES I BELAMPALLI Middle Measures MEASURES I zone·l N G A Lower Coal BARAKAR BARAKAR BARAKAR BARAKAR BARAKAR R Measures E N TALCHIR TALCHIR TALCHIR TALCHIR I TALCHIR TALCHIR TAL C HI R there is growing necessity for the uniformity in Within the Godavari Graben the stratigraphic stratigraphic classification and terminology because status of 'Kamthi' Formation has been interpreted in the informal usage in the past has led to much different ways by different authors (Table 1). confusions. An anempt has been made to ellucidate Ramanamurtyand Rao(996) classified the Kamthi the current status of the Kamthi Formation in view of sediments (sensu Raja Rao, 1982) into Raniganj and the lithological, palynological and plant fossil data Kamthi Formations, .the latter divisible into two accumulated during recent years. Before going into members. ]ha and Srivastava (996) in their the details it is essential to understand the Kamthi in classification considered the Lower Member being type area (sensu stricto) and its relationship in equivalent to Panchet Formation and Upper Member different basins. being equivalent to Supra-Panchet/Mahadeva Formation. STATUS OF KAMTID FORMATION IN DIFFERENT BASINS LITHOLOGICAL SET-UP The Kamthi Formation as described by Blanford The lithological set-up of Kamthi Formation in has been given in introduction. The status of Kamthi Godavari Graben is given in Table 2. Formation in different basins is as follows: Kamthi Formation (Raja Rao, 1982) in Wardha and Kamptee coalfields overlies Mowr Formation Wardha Kamptee Godavari Mahanadi (=Barren Measures) and underlies Lameta Formation K Supra Panchet with pronounced unconformity at both the ends. A -Mahadeva M KAMTHI KAMTHI KAMTHI T In Mahanadi Valley the sediments unconformably H Panchet I overlying the Barakar Formation are included within RANIGANJ RANIGANJ the Kamthi Formation. It consists of fine to medium­ ' BARREN Mowr Mowr BARREN MEASURES grained sandstone, carbonaceous shales, coal bands MEASURES with greenish sandstone, pink clays and pebbly 90 THE PALAEOBOTANIST Table 2-l1thological set-up ofPermlan-TriasslcsedimentsInthree sub-basins ofGodavarl Graben. (A) lndlcatessensu RajaRao (1982), and (B) sensu Jha and Srivastava (996) and Ramanamurty and Madhusudan Rao (1996) A B GODAVARI KOTHAGUDEM CHINTALPUDI SUB-BASIN , SUB-BASIN SUB-BASIN z z 0 0 i= '" I- -< a:l -< '"""a:l :::<: "" :::<: :::<: :::<: U P PE RG 0 ND W A N A '"0 "" '"0 "- :::<: "- "":::<: Predominantly ferruginous Kamthi : Coarse to Kamthi : '" '" sandstone with subordinate pebble sandstone ""<>. - ""<>. Congolomeratic <>. <>. siltstone and day bands arid clays. (SCa, ::> ::>. sandst()ne, ferrugi- - :r: forming hills ranges 1982, in Lakshmi- nous sandstone, I- - narayana & l- siltstone Pinkish, violet :r: Red/brown sandy Murty, 1990). Chocolale brown siltstone/sandstone and indurated and yellow sst. calcareous clay and and clay I- :::<: claystone crossbedded sandstone ,~ (Lakshminarayana ,-. < "" ...."" & Murty, 1990) :::<: 0 0 u 0 Greenish grey to green ..: ""'" Greenish Greenish grey ..: ~ :::<: " :::<: clay, siltstone inlercalated < 0 grey clay <U sst. / siltstone .... <U (:; with sandstone, u u micaceous at places <U ..: " <U (:; (:; Mg-Cg greyish a:l Mg.cg greyish white a:l while sandstone Fg-Mg. grey sandstone with RANlGAN] sandstone "" Grey to black shale ~ subordinate shale and carbshale and 0 .... coal seams and coal seams coalseams Unconfonnity Unconfonnity BARREN MEASURES BARREN MEASURES BARREN MEASURES sandstone at the top (Raja Rao, 1982). However, sub-basins have also shown the presence of three recent investigations through Kamthi Formation in litho-units (Table 2). Talcher and Ib-River coalfields have shown a close Initially the Kamthi Formation (sensu Blanford, proximity with that of Godavari Graben and all the 1872; Hughes, 1877) was distinguished from Raniganj three litho-units are recognisable and correlatable Formation on the basis of absence of coal or (Table 3). carbonaceous deposits or even carbonaceous Remarks-The entire sedimentary sequence markings. Now there are sufficient evidences for the above the Barren Measures and below the Yerrapalli presence of coal seams in lowermost litho-unit in Formation in Godavari Graben aSSigned to Kamthi Godavari, Wardha and Mahanadi valleys which Formation by Raja Rao (982) is actually divisible exhibit gross lithological similarity with Raniganj into three litho-units: CD the lowermost unit consists Formation ofDamodar Valley. The distinct lithological ofgrey shale, carbonaceousshale, coal and sandstone, change occurs at the base of the middle unit (ii) the middle unit comprises greenish-grey shale, represented by greenish grey clay, shale and clay and sandstone overlain by medium to coarse sandstone and is equivalentto the Panchet Formation grained sandstone with pinkish red/brown/purple of Damodar Basin (Table 4). This transition is clearly shales/clays, and (iii) the topmost unit consists of demonstrated in Mailaram, Budharam areas of ferruginous sandstone with sub-ordinate siltstone, Godavari Graben, Bazargaon area of Kamptee clay bands and pinkish red to purplish brown and Coalfield and Chendipada Block of Talcher Coal­ yellow limnoic shales. Recent drillings and previous field. The Upper Member of the Kamthi Formation geological data in Kothagudem and Chintalpudi forming prominent ridges in Godavari Graben exhibits SRIVASTAVA & JHA- STAnJS OF KAMTHI FORMATION 91 Table 3---Uthologlcal set-up of Permlan-Trlassic sediments In Wardha,