On the Microscopic Nature of Coals from Majri Area, Wardha Valley Coalfield, Maharashtra

ON THE MICROSCOPIC NATURE OF COALS FROM MAJRI AREA, WARDHA VALLEY COALFIELD, MAHARASHTRA H. S. PAREEK & B. C. PANDE A 1/4, Paper Mill Colony, Lucknow ABSTRACT of deposition, the present Wardha-Godavari The microscopic nature and composition of the valley basin, is evidenced by the similarity coals from Majri (200 8': 790 2') area, 'Vardha of the geological features, lithological nature Valley coalfield, Maharashtra, about which no of the rock types, and a cover of the Upper data whatsoever exists, are presented in this paper. Gondwanas existing between these coal• These are microfragmental coals, comprising inerti• nite, vitrinite and exinite (sporinite), in decreasing fields. Pande (1970) reports the recer.t order of abundance, occurring as mainly durite, findings of coal-measures under the younger fusite, "intermediates ", c!arite and vitrite. The sediments, like the Kamthis and Lametas. mineral and shaly matter is quite common and Whether the microscopic nature of the coals thoroughly intermixed with the organic layers, which alternate or are interbeddcd with shale and from these coalfield areas is similar or carbonaceous shale bands. different, is not yet known, since no data, The Vv'ardha valley coalfield is separated to its whatsoever, exists on the Majri coals or south-east from the adjacent Godavari valley of other areas in the Wardha valley, al• coalfield by the Upper Gondwanas. The coal• bearing formations of these coalfields may thus though data on coals of the Tandur area in continue below this cover. A large spread of the the Godavari valley coalfield is available Gondwana sediments, whercby these coalfields (Chatterjee et al., 1966; Ghosh, 1962; Pareek form only a part of the 'Vardha-Godavari valley et al., 1965; lho, 1962; Rao & Razvi, 1965). basin, is thus suggested. The petrological studies of the Majri, and Tandur (Godavari valley coal• Stu.dies of the Wardha valley coals in the field) coals have indicated close proximity, than Majri area were, therefore, taken up and with the coals of the othcr basins. There is, the data is presented in this paper. The however, a lateral variation in the composition of area was examined by one author (B.C.P.), coal, and that appears to be related to the source of sediments, conditions of deposition and the who collected the samples of coal that vegetal transformation. form the basis of this study. INTRODUCTION GEOLOGY OF THE AREA The Gondwana sediments cover an area the Majrinorthern-most(20°8': 79°2')portionareaofformsthe of over 4000 sq. km. in the Wardha valley THEWardha valley coalfield, named after basin. The main coal-bearing areas are the River Wardha traversing thlOugh the the Warora-Majri, the Wun-Rajur, and area, and falls in the district Chandrapur Ghugus-Telwasa, in the westeffl sector, of Maharashtra. It is estimated that about and the Chanda-Balharshah, Sasti-Rajura, 32 million tons of coal will be available in and Lathi-Antargaon in the eastern sector. this part of the coalfield (Roy, 1962a, p. 28). The Majri area forms the northern part of The coal extracted from the mines existing the Wardha valley coalfield. Text-fig. 1 at Majri is of the order of 60,000 tonnes shows the geology of the coalfield, and the per year, and is being used as a fuel for location of the Majri area. domestic needs, in steam generation for the The "Wardha valley coalfield extends in locos, and in industries. a NW-SE direction, with the Archaeans, The Wardha vallfY coalfield falls to the forming its eastern boundary, and the north-west of the group of the Godavari Puranas and the Vindhyans constituting valley coalfields. The Wardha and Goda• its western boundary. The Talchirs appear vari valley coalfields are separated by the in the central portion of the coalfield, with stretch of Upper Gondwanas, extending isolated, disconnected, tiny outcrops of the over a strike length of 20 km., being also Barakars on its either sides. The bulk of the trend of their disposition. That they the eastern and weste~'n sectors of the coal• once formed part of a large spread of field is covered by the Kamthis, which Gondwana sediments in one original basin have an angular conformity, concealing 76 PAREEK & PANDE-MICROSCOPIC NATURE OF COALS FROM MAJRI AREA 77 80· KEY MAP Pauni LIST OF +9Ut.~~.... 2.TANDURI. SIRONCHA +C;~I~fi:ld LOCALITIES ~':-: -:-:. + f\. 4.3. ADILABADRAJURA . '" +.p + 5. BALHARSHAH 6.CHANDA v 7. GHUGUS 8.MAJRI 9.WARORA + o 19 INDEX + I~ ~ ~I Alluvium. + ~ Deccan Trap. illIIIIIIl Lam et a s. 1-:--.:..-:-1 Upper Gon dwanas. + ~ Lower Gondwanas. SCALE IN KMS ~ Vindhayans. 20 0 20 40 60 80 , ! I I I ! E:::I:::SCuddapahs. E3 Metamorphics. ad' TEXT-FIG. 1- GEOLOGICAL MAP OF THE NORTHERN PART OF WARDHA-GODAVARI VALLEY BASIN (AFTER HUGHES. 8 KING). 78 THE PALAEOBOTANIST underneath the entire sequence of the fication of coal scams difficult. Unless deep Karharbari and Barakar formations (see bore holes penetrate through the Kamthi Pande in Roy, 1962b, p. 44,1963, p. 81-82). cover, and the Barakar sequence, and com• The Lameta beds occur as isolated outcrops parisian of the bore hole data made, the on the north and north-west, while rest of qualitative and quantitative assessment of the area is generally covered by the basaltic the seams cannot be made with certainty. traps. The Gondwana sediments seem to The sporadic published records available have a broad gentle anticlinal structure with from the bore holes which have so far been the western limb folded again near the drilled and the data available from the faulted western contact (see Pande in Roy, working colliery at Majri, indicates exist• 1964, p. 62). ence of one seam of over 15 metres thick• The generalized sequence of the geologi• ness in the area. cal formations met with in tIle coalfield Hughes (1877) recorded a coal seam of appears in Table 1. The thickness of the 15 metres thickness in between Majri and individual strata is difficult to be assessed, the R. Wardha. Fox (1934) reported two in view of the overlapping nature of the coal seams of 4·5 m., and 17·5 m. thickness beds, but the total estimated thickness of in separate boreholes, west of the village the Lower Gondwana sequence may range near Kona-Naglon track. He also reported up to 182 metres. one coal seam of 4·5 m. thickness at 52 metres depth, and another of 3·3 m. at 66 COAL SEAMS metres depth in a carbonaceous horizon of 17 metres in the borehole near Pit I in the The coal scams of the area do not out• \Varora colliery area. Exploratory drilling crop anywhere, since the Barakars underlie has been undertaken by the Geological a thick cover of the Kamthis and the Survey of India, and is in progress to deter• Lametas. This has rendered the cla~si- mine the extent of the overlap of the TABLE 1 - GEOLOGICAL SEQUENCE OF ROCK FORMATIONS AGE ROCKFORMATIONS Recent Gravel beds Upper Cretaceous to Lower Eocene Deccan Trap• Basaltic rocks Upper Cretaceous Lameta beds- Marls and calcareous sandstones - - - - - - - - Unconformity - - - - - - - • Upper Gondwana E:ota and Maleri beds- Sandstones and fossiliferous siliceous limestones --------lli=fu~~-------• r Kamthi Series- 1 Ferruginous sandstone, coarse to medium grained, and - - - - - - - - Unconformity - - - - - - - • I BarakarvariegatedSeries-shales and clays 1 Felspathic sandstone, occasionally gritty, carbonaceous Lower GOndwana ~I E:arharbarishale, shale,Stage-and coal seams 1 Even-grained glauconite-bearing sandstone, thick beds of I Talchirclay, andSeries-thin coal seams I Hard compact equi-grained greenish sandstone, with un- l decomposedneedle-shapedfelspars,shales and olive green, occasionally typically Pre-Cambrian to Lower Palaeozoic Vindhyans--------lli=furm~--------and Puranas• Sandstones, shales and limestones --- - - -- - Unconformity ----- --• Archaeans Metamorphics - Gneisses PAREEK & l'ANDE - MICROSCOPIC NATURE OF COALS FROlYI lYIAJH.I AREA 79 Kamthis over the Barakars and disclose common. A thin-walled woody layer in possible coal seams. while determining the compacted state appears in Fig. 10. The structure of the Gondwana basin (Roy, fusinized tissues of thick-walled cells are 1966; Jhingran, 1967). Existence of a thick no so common. Fragments or a fusinised carbonaceous horizon of thickness 16·63 m.• thick-walled cellular tissue appear in the 19·85 m. in the Majri area has also been upper portion of the Fig. 11. reported, with the coal seam dipping 12° Fusinized resins are conspicuous micro• to 15° towards S. 55°_65° W. (Jhingran, constituents and occur in a variety of shape 1967). and form. They exhibit moderate to high Tbe Majri colliery is working the bottom reflectivity in polished sections, under oil section of this seam, which is of 9·5 m. immersion (Figs. 4, 5, 6, 7, 9), and appear thickness in NO.3 Air Shaft. Between the opaque even in the thinnest thin section R. Wardha and the colliery, over a distance (Fig. 12). Massive or with canals or voids of 3 km., this seam thickens to 15·5 m. (Figs. 4, 6, 7, 12), and highly vesicled with well-developed partings of sandstone, varieties (Figs. 5, 9) are common and vary shale, carbonaceous shale, etc., up to a considerably in size. The occurrence of thickness of about 7 metres. From the fusinized resins in different Gondwana coals available data, it thus transpires that one is illustrated and described in another paper coal seam of over 15 m. thickness with many (Pared:, 1966). partings extends over most of the area. Semifusinite, the transitional stage Chemically, the Majri coals have high between vitrinite and fusinite, is not un• moisture (9-12%), volatiles (31-35%), and common. Fragment of such a semifusinized highly variable ash up to 43 per cent. The tissue appears in the central portion of Fig.

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