IETRO-pALYNOLOGICAL STUDY OF THE COALS EXPOSED NEAR GOPALPRASAD OF TALCHER COALFIELD (ORISSA), INDIA G. K. 13. NAVALE & SURESH C. SRIVASTAVA Birbal Sahni Institute of Palaeobotany, Lucknow ABSTRACT Gopalprasad or Gopalprasad seam'. The The samples collected from the exposed beds of seam is 23' thick, very much banded with coal near Gopalprasad have been studied since no high ash content and is exposed only for previous knowledge exists about the microstructure a very short distance along Tengria Nala. and microfossil contents of this coal. Blandford et al. (1859) have collected from The coals are typically dull, fine-grained and hard this bed all fossils found in Talcher basin in nature. They are constituted by Vitrinite, Exinite, Inertinite organic macerals and sedimen• and have suggested a probable resemblance tary mineral matter. Among these Inertinite and of some of these forms to those found in mineral grains dominate the coal components. Damoodah and Nagpur coalfields. The Rapid alternatin~ bands of Durite and Carbargillite and increasing high percentage of mineral matter overlying and underlying sediments in the makes the coal more dull and shaly. area are not known. at present. A coal Sporological analysis reveals that the coal con• seam, presumably similar to Gopalprasad sists of 20 genera including a number of trilete, 120°58' : 85°2'), is reported to occur in the monolete, monosaccate and bisaccate spores. The Hingir Coalfield (BALLand SIMPSON,1922). miospore assemblage dominates in striated bisaccate spores with subdominance of non-striaten pollen. The present investigation has been carried Trilete miospores are less common, while mono• out since no knowledge exists about the saccates are rare. The common striated bisaccate microstructure and palynological contents genera are Faunipollenites, 5triatopodoearpites, Lahi• rites and Striatites while nonstriated bisaccate of the coal beds exposed near Gopalprasad, g~nus is Suleatisporites. Talcher Coalfield, although detailed petro• Petro-palyhologically, compared with the Lower logical data of Talcher coals restricted to Seam and Upper Seam No. 1 of Talcher Coalfield the working coal horizons are available and others, the coals are of very inferior quality and (PAREEK' 1963, 1965). Das (1958, 1959) referable to Upper Barakar Stage in Lower Gond• also has done some preliminary investiga• wana sequence. tions into the Fusain and microft.oral contents of Talcher Coalfield in general. INTRODUCTION Recently Pant and Srivastava (1963) have studied the megaspores from this coalfield and Navale (1966) has also studied in general TALCHERmani RiverCoalfieldValleylies betweenin the Brah•the the petrological and palynological consti• longitudes 84°20' North and lati• tuents from the working mines ( .C.D.C.) tudes 20°50' and 20°13' East. On its of Talcher Coalfield. North-West boundary it is connected with Coal blocks were collected from the top, the neighbouring Ib-river Coalfield by a middle and bottom portions of the exposed narrow prolongation of Talcher Series bed near Gopalprasad village. An over• rocks. all representative sample of 18 B.S. mesh Considerable knowledge now exists about size were prepared and 5-10 gms out of the the geology of the area (BLANDFORDet al. same were macerated for preparation of 1859, PAREEK'1965 & NAVALE1965). The thin slides in glycerine jelly. Palynological coal horizons of the area are known to con• units were carefully identified and photo• sist of 3 thick seams, viz. Lower seam, graphed. 500 specimens were counted Upper seam No. I and Upper seam No. II, and their percentage frequency were besides 4 thin and impersistent ones. The determined with a view to evaluate the seams usually do not outcrop anywhere mioft.oral association. Particulate coal pel• due to its ft.at gradient and low degree of lets of the overall samples were moulded inclination. However, one seam is exposed with thermoplastic resin Araldite and re• near Gopalprasad village and is usually quisite Hardener, one surface of which was known as 'Carbonaceous shale bed of grinded and polished. Petrological con- 258 NAVALE & SRIVASTAVA - STUDY OF COALS EXPOSED NEAR GOPALPRASAD 259 tents were studied in polished surface by makes the organic microconstituents incon• reflected light under the microscope. The spicuous (PL. I, FIGS.1,5). They are dark percentage frequency of the occurrence of grey in colour with both the edges smooth, macerals were done by point counter. and usually cut in different planes and as such show no morphographical defferentia• tion. Exinite macerals are mostly as• PETROGRAPHY sociated with thin Collinite bands, the interestitial spaces of which are mostly The coals of Gopalprasad bed are typi• filled with clay minerals. Megaspore exines cally dull Durain type. They are hard, are rare and wherever they occur are mostly fine grained in texture, nonbanded and filled with organic mineral deposits. non fibrous in nature. In general appear• Cutinite and Resinitc are also rare in ance they look like carbonaceous shale, occurrence. hence, the name 'Carbonaceous shale bed Inertinite - PI. I, Figs. 3-6. of Gopalprasad'. This group of maceral is the most domi• Under microscopic analysis it shows to nant component in the present investi• consist of the following maceral groups; gation and consists of Fusinite, Semi• Vitrinite, Exinite and Inertinite. The fusinite, Fusinised Resin and Mineral quantitative distribution of the macerals matter. Amongst these, the last maceral are as represented in Text-fig. 1. predominates over other ones. Its total Vitrinite - PI. I, Figs. 1 and 2. volume representation ranges upto 69 per This maceral is represented upto 25 per cent (TEXT-FIG. 1). cent (TEXT-FIG. 1) and consists mostly of Fusinite is present in fairly good nonstructured Collinite (PL. I; FIG. 1). Col• amounts (3·6% by volume). The tissues linite is present only in the form of thin are mostly derived from woody remains and sheets or fragmentary strips which do not the cells are distinctly preserved. Cell exceed more than 1 mm in thickne3s. The lumens are either empty or filled with mine• Collinite fragments are mostly teared up, ral matter (PL. I, FIG. 4). Fusinized fungal thinning into lenticular extensions or in structures also occur but infrequently. fish-tail pattern (PL. I, FIG. 2). Also these Fungal structures, distinctly preserved, bands are traversed by numerous cracks are either one celled or more than one celled and fractures perpendicular to the plane of structures with thick walls. These struc• stratification (PL. I; FIG. 2). This character tures are mostly empty (PL. I, FIG. 6). may indicate that the source of the maceral Semifusinites are more common than might have undergone extensive crushing Fusinite and are present upto 13 per cent and tearing during drifting of vegetation. by volume. They occur in the form of They do not show any botanical details thin bands or fragments of not more than clue to carbonization and are dull, dark grey 0·5 mm in thickness. Fuzinised resins in colour. Collinite bands are invariably are rather uncommon and wherever present associated with Exinite group of macerals. arc small rounded bodies impregnated Pyrite and clay minerals always fill in the mostly with mineral matter. Rounded cleats and fractures of the Collinite bands. pockets of semifusinite are also present, Clay minerals even lie scattered over the which suggest the extensive rolling of surface of woody macerals and make their vegetation before being deposited (PL. I, structure insignificant. FIG. 3). Exinite - PI. I, Figs. 1-2. Mineral and shaly matter are present Exinite group of maceral is present in in high amounts being present upto 52 per very poor amounts and ranges upto 6 per cent by volume (TEXT-FIG. 1). These cent by volume (TEXT-FIG.1). The main secondary inorganic deposits chiefly mask maceral component consists of miospore the true nature of other microconstituents and megaspore exines together grouped (PL. I, FIG. 5). They are found intimately in Sporinite. The microspore exines are associated with Vitrinite, Exinite, Fusinite thin narrow bands flattened parallel to the and Semifusinite. The chief inorganic stratification. Exinite macerals are distin• minerals identified in association are pyrite, guishable only under high magnifications siderite, clay and shaly matters. Pyrite of the microscope as they are mostly occurs as small discrete bodies with bright associated with high mineral content which luminosity and lie in betweeen the cleats 260 THE l'ALAEOBOTANIST GOPALPF\ASAD SEAM TALCHER COALFIELD o 10 20 30 40 I I I LEIOTRI LETES CALLUMfSPORA HENNELYSPORITES VITRINITE CYCLOGRANfSPORIT E S LOPHOTRILETES HORRfDITRILET E EXINITE MICROBACUL I SPORA CALAMOSPOR.A SEMIFUSIN IT E LATOSPOR.ITES POTONIEISPORITE 5 FUSINITE CUNEATISPORITES FUSINISED RESIN PLATYSACCUS STRIATITES LAHIRITES MINERAL STRIATOPODOCARPITES MATTER VERTICIPOLLENITES FAUNIPOLLENITES VESICASPORA SULCATISPORITES GINKGOCYCADOPHYTUS TEXT-FIG. I - SHOWING PERCENTAGE FREQUENCY OF MIOSPORES AND MACERALS and fractures of Vitrinite, cell lumen of Vitrite, Clarite, Fusite and 'Trimacerite' Fusinite and Semifusinite. Simple iso• are rather uncommon. Rapid alternating lated Pyrite grains or compound ones both microbands of Carbargillite and fine-grained are found in these deposits. Siderite occur Durite characterizes the association under always associated with shaly matter. Shaly microscope. The Carbargillite itself con• matter and clay minerals are the chief stitute more than 50 per cent of the