The Palaeobotanist 35(3) : 301-313, 1986.

.... Palynology of the ]aintia Group (Palaeocene-Eocene) exposed along ]owai-Sonapur Road, Meghalaya, (Part II). Data analysis and interpretations

H. P. Singh & S. K. M. Tripathi

Singh, H. P. & Tripathi, S. K. M. (1987). Palynology of the jaintia Group (Palaeocene Eocene) exposed along jowai-Sonapur Road, Meghalaya, India (Part II). Data analysis and interpretations. Palaeobotanist3S(3) : 301-313. The palynoflora recovered from the jaintia Group (Palaeocene-Eocene) exposed along the road between jowai • and Sonapur, jaintia Hills has been dated and compared with various Lower Tertiary palynological assemblages. The present studies support tropical to subtropical vegetation during the Palaeocene-Eocene times. It has also been inferred that the jaintia Group sediments were deposited under shallow marine conditions. Key-words- Palynology, Stratigraphy, jaintia Group, Palaeocene-Eocene (India).

H. P. Singh & S. K. M. Trzpathi, Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow 226007, India.

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THE sediments of ]aintia Group are exposed along Therria Formation (about 100 m thick) is National Highway 44, connecting constituted by monotonous white-brown and pale­ (Meghalaya) and Badarpur (). These sedi­ red, medium to very coarse-grained, often gritty, ments belong to the shelf facies and are exposed cross-bedded, ferruginous , alternating between ]owai and Sonapur, southeast of Shillong. with subordinate and fine-grained carbona­ The ]aintia Group is divided into three formations, ceous sandstone. The shale is mostly bentonitic and which in the ascending order are: Therria without megafossils. The carbonaceous Formation, Sylhet and Kopili Formation. are generally associated with thin coal seams. At ]owai, the Shillong Group (Precambrian) is The Sylhet Limestone (about 500 m thick) is unconformably overlain by the Therria Formation. made up mainly of limestone with thin alternations Further south-ward, the Therria Formation is of sandstone and consists of five members. Kopili overlain by the Sylhet Limestone which in turn is Formation, the youngest stratigraphie unit of the succeeded by the Kopili Formation (Map 1). ]aintia Group, is made up of grey, fine to very fine Detailed geological information and a geological grained, massive to laminated, compact sandstone, map of the area have been published by Saxena and alternating with . The shales represent Tripathi (1982). ellipsoidal structures shOWing laminae like

30] 302 THE PAlAEOBOTANIST successive layers of onion. Kopili Formation is about palynofloral assemblage. The presence of various 500 m thick. palynotaxa in the three formations is as follows: Sein and Sah (1974) on the basis of FORMATION palynological study, mostly at generic level, demarcated the Eocene and Oligocene sediments D-1ERRlA SYLHET KOPIL! exposed along the road between Lumshnong and Cyathidites australis + Sonapuf. Later, Duna and Jain (1980) described Intrapunctisporis densipunctis + acritarch and dinoflagellate assemblages from the Dandotiaspora dilata + + D. telonata + + + Sylhet Limestone and Kopili Formation in the Lum­ Dandotiaspora sp. + shnong area and pointed out their biostratigraphic Biretisporites sp. + potential. However, palynostratigraphical infor­ LygodiumspOrites eocenicus + + mation available so far from this area is meagre and L. meghalayaensis + the results are based on study of limited number of L. khliehriatensis + L. marginiplica'tus + samples. L. psilatus + The present analysis of palynological data is Todisporites major + + based on 318 samples which were collected Osmundacidites sp. + from stratigraphically measured sections. Of these, Corrugatisporites sp. + 160 samples proved to be productive, yielding a rich Foveotriletes pachyexinous + Foveotriletes sp. + palynofloraI assemblage constituted by algal, fungal, Striatriletes susannae + pteridophytic and angiospermic remains. Systematic S. paucicostatus + palynology alongwith critical observations has S. attenuatus + already been dealt with by Singh and Tripathi Cingutriletes sp. + (1983), Tripathi and Singh (1984a), Tripathi and Monolites mawkmaensis + Singh (1985), Singh and Tripathi (1986) and Tripathi M. discordatus + Polypodiisporites mawkmaensis + (in Press). Verrucatosporites sp. + A paper on palynostratigraphical zonation and Schizaeoisporites sp. + correlation of the Jaintia Group sediments, exposed 5ciadopityspollenites sp. + + along Jowai-Sonapur Road, Meghalaya has also been Trijossapollenites constatus + published by Tripathi and Singh (1984b). In the Couperipollis brevispinosus + + present paper a comparative account of the C. meghalayaensis + C. wodebousei + assemblages known from the stratigraphically C. robustus + equivalent horizons is given and palynological data C. rarispinosus + has been analysed qualitatively and quantitatively to Couperipollis sp. + reflect upon palaeogeography, palaeoclimate, pala­ Liliacidites microreticulatus + L. giganticus + + eoecology and age of the sediments. L. major + Collospermumpollis laevigatus + Palmidites plicatus + + PALYNOFLORAL COMPOSITION AND ITS p. obtusus + + + P. maxim us + QUALITATIVE ANALYSIS Palmaepollenites communis + Pinjoriapollis magnus + The Jaintia Group (Palaeocene-Eocene) sedi­ Proxapertites assamicus + ments exposed along the road between Jowai and Assamialetes emendatus + Sonapur, Meghalaya have yielded 59 genera and 92 Ladakhipollenites elongatus + Tricolpites alveolatus + + species. Out of these, 15 genera and 25 species Trisynocolporites angularis + represent the pteridophyte5, 20 genera and 29 Retitrescolpites sp. + species represent the angiosperms, 13 genera and 26 Tricolporopollis rubra + + + species represent the algae and 11 genera and 12 Densiverrupollenites eocenicus + species represent the fungi. Lakiapollis assamicus + Myricipites vulgaris + Qualitatively angiospermous pollen grains Graminidites maxim us + exhibit tneir dominance over other plant groups but Polyporina sp. + quantitatively pteridophytic spores constitute the Gonyaulacysta sp. + major part of the assemblage (30%). The Apteodinium sp. + + dinoflagellate cysts (algae) constitute 29% of the Turbiospbaera jilosa + T proximata + total palynofloral assemblage, while the Apeetodinium homomorphum + angiosperms share 20% of it. The fungal remains are A parvum + represented by 2% only. Gymnospermous pollen Apeetodinium sp. cf. + grains are conspicuously absent in the present A hyperacantbum SINGH 8i TRIPATHI-PALYNOLOGY OF THE JAINTlA GROUP 303

Homolryblium lenuispinosum + Schizaeaceae H. oceanicum + H. p/ecli/um Schizaeoisporites sp. appears to be related to Cordosphaeridium exilimurum this family due to the comparable spore morpho­ ~ C mU/lispinnsum + + C. valianlum + logy. This family is chiefly distributed in the tropical Cordospbaeridiul11 sp. + and subtropic.al regions of the world. Lygodium­ Prolixosphaeridium conu/um + sporites and Intrapunctisporis also show affinity with Imp/elospbaendi/lm sp. + this family. Po/yspbaeridium subli/e + + P giganleum P. ornamenlum + Cyatheaceae Opercu/odinium cenlrOCalpul11 + + 0. israelianum + Cyathidites australis resembles the spores of the 0. major + + family Cyatheaceae. Presently plants of this family Adnalospbaeridium villalum + + A. robus(um + are found mainly in the tropical and subtropical Codoniella /angparensis + areas of the world. Eocladopyxis sp + Callimolhallus perlusus Osmundaceae Pbragmolbyriles eocenica + + PbragmOlbyriles sp. + Paramicrolhalliles sp. + Todisporites major and Osmundacidites sp. Microlbal/iles sp. + resemble the spores of the family Osmundaceae. Cucurbilariaciles bellus + P/uricel/aesporiles psi/alus + Parkeriaceae Dicellaesporiles popovii + Dicel/aesporiles minulus + Diporisporiles sp. + The genus Striatriletes is quite similar to the Dlporicel/aesporiles sp + spores found in Ceratepteris (Parkeriaceae). This is a Inaperlisporiles sp. + water fern and is distributed in the tropical and sub­ tropical regions of the world. Botanical affinity of studied spores and The angiosperms are represented by the pollen grains has been inferred by comparing their following families: morphographic features with those of the living ones. Mostly the published information on the Palmae morphology of spores and pollen grains has been used for this purpose. In most of the cases the Palmidites, Palmaepollenites and Couperipollis affinity could be traced only up to family level, resemble the pollen grains of the family Palmae. The however, in some cases it has been possible to present day distribution of this family is restricted to compare them up to the generic level as well. The tropical and subtropical regions of the world. pteridophytes are represented by the following families: Liliaceae Lycopodiaceae Liliacidites and Collospermumpollis are closely Foveotriletes pachyexinous and Foueotriletes sp. comparable to the pollen grains of the family are comparable to the spores found in some Liliaceae. This family is cosmopolitan in the present members of the family Lycopodiaceae. This family is day distribution. presently found in tropical to temperate regions and favours moist and shady places. Graminae

Polypodiaceae Graminidites maximus resembles the pollen grains of the family Graminae. This family is cosmo­ The family Polypodiaceae is represented by politan in the present day distribution. Monolites mawkmaensis, M. discordatus, { Polypodiisporites mawkmaensis and Verrucatos Nymphaeaceae porites sp. The present day distribution of this .family is cosmopolitan. This family appears to be represented by the pollen grains of Proxapertites assamicus. The Matoniaceae present day distribution of this family is mainly Biretisporites and Dandotiaspora are doubtfully restricted to the tropical regions. It is an aquatic related to the fern family Matoniaceae. family. 304 THE PAlAEOBOTANIST

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Nelumboniaceae Chenopodiaceae

Pollen grains assignable to Assamialetes The family is represented by Polyporina sp. emendatus resemble the pollen grains of this family. However, similar pollen grains are also found in the This family is also aquatic and is restricted to the family Amarantaceae. tropical regions of the world. Euphorbiaceae

Cruciferae Tricolporopollis rubra and Lakiapollis assamicus are comparable to the pollen grains of the family Ladakhipollenites elongatus resembles the Euphorbiaceae. The present day distribution of this pollen grains of the family Cruciferae. This family is family is cosmopolitan. Pollen grains of similar cosmopolitan in the present day distribution and it morphology are also found in the family Araliaceae. grows in diverse conditions. However, pollen grains of similar morphology are also found in the family Myricaceae Polygonaceae. Myricipites vulgaris shows affinity with the Oleaceae family Myricaceae. The present day distribution of this family is restricted to subtropical to temperate regions of the world. Myricipites vulgaris is The family appears to be represented by the abundantly found in the Indian Tertiary sediments but pollen grains assignable to Retitrescolpites sp. The during the present study its frequency was found to be day geographical distribution this family present of extremely low. is restricted to tropical and warm temperate regions of the world. Magnoliaceae Labiatae This primitive family is probably represented in Tri] ossapollen ites cons ta t us dou b t fu 11y the assemblage by Pinjoriapollis magnus. The represents this family. The family is cosmopolitan in present day distribution of this family is in the the present day distribution. temperate regions of the world. SINGH & TRIPATHI-PALYNOLOGY OF THE JAINTIA GROUP 305

?Aristolochiaceae represented in the Therria Formation but absent in the Subathu Formation arc Tllrhiosphaera, The genus Sciadopityspollenites may doubtfully Apectodinium, Operculodinilll'll, AdllatospIJaeri be related to the family Aristolochiaceae. The affini­ dium and Codoniella. Besides, many angiospermous tI!!!tI ties of Tricolpites alveolatus and Densiverrupollen­ pollen grains, pteridophytic spores and fungal ites eocenicus are uncertain. remains have been recovered from the Therria PalynofloraI assemblage recovered from the Formation, which are not present in the Subathu Palaeocene-Eocene sediments of ]owai-Sonapur Formation. Road section, Meghalaya reflects a tropical to sub­ A comparative study of the palynological assem­ tropical type of vegetation; however, a few blages from the Therria and Subathu Formation temperate elements were also encountered. reveals that the former is dominated by the pterido­ phytic spores and angiospermic pollen grains, while PALYNOFLORAL COMPARISON the latter is characterized by the abundant occurrence of dinoflagellate cysts. A few Basin dinoflagellate cyst genera are common between the two formations, but most of the elements are not Palynological studies on the Subathu Formation comparable. Singh, Khanna and Sah (1978) assigned have been carried out by Mathur (1963, 1966); an Upper Palaeocene-Upper Eocene age to the Salujha, Srivastava and Rawat (1969) and Singh and Subathu Formation. Khanna (1980). The Subathu palynological assemb· lage described by Salujha, Srivastava and Rawat (1969) comprises 28 genera and 45 species. Of these, 10 genera belong to pteridophytes, 1 to Bose (1952), Singh and Natrajan (1950) and gymnosperms, 12 to angiosperms and 5 to micro­ Jain, Kar and Sah (1973) investigated the Barmer planktons. The palynofossils are poorly preserved Sandstone of Rajasthan palynologically. The precluding a close comparison. However, Todispo· palynoflora described by Jain, Kar and Sah (1973) rites (Scabratriletes), Dandotiaspora (Psilatriletes comprises 36 genera and 43 species, of which Proxa­ lobatus), Osmundacidites (Scabralrileles sp. A), pertites, Tricolpites, Palmaepollenites, etc. are Couperipollis (Echinomonoleles) and I'allllaepolle­ common between the two assemblages. The nites (Retimonocolpiles) appear to he common to follOWing Barmer Sandstone forms are absent in the both the assemblages. forms restricted to the present assemblage: Araliaceozpollenites, Proteaci­ Subathu Formation are: Lycopodiacidites, Polypodia­ dites, Extratriporopollenites and Triorites. Many ceaesporites, Granodlporites, Anacolcidites, Triorites, palynofossils present in the Therria Formation are Nyssapol/en i tes, Polycolpi tes, Mic rohystrid iu m, absent in the Barmer Sandstone. The Barmer Canno-sphaeropsis, etc. The palynofossils restricted Sandstone has been assigned a Palaeocene age (Jain to the Therria Formation but not reported from the et aI., 1973). Subathu Formation are: Inl1'apunctisporis Rao and Vimal (1950, 1952) and Sah and Kar densipunctis, Foveotriletes, Monolites, Liliacidites, (1974) made palynological studies on the Palana Assamialetes, etc. beds, Rajasthan. The paFynological assemblage des­ Recently Singh, Khanna and Sah (1978) and cribed by Sah and Kar (1974) is richly diversified Singh and Khanna (1980) carried out a detailed paly­ and consists of 32 genera and 47 species. The nostratigraphic study of the Subathu Formation and palynotaxa common between the Palana beds, recovered a rich palynofloral assemblage. The Rajasthan and Therria Formation, Meghalaya are: assemblage recorded by Singh and Khanna (1980) Todisporites, Osmundacidites, Dandotiaspora dilata, consists of 15 dinoflagellate genera, 4 pteridophytic Schizaeoisporites, Palmaepollenites, Iiliacidites, genera, 2 gymnospermic genera and 5. angiospermic Couperzpollis, Tricolpites, and Callimothallus. The genera. The palynotaxa common to the Subathu and forms present in the Palana beds but absent in the Therria formations are: Cordosphaeridium, Homo­ Therria Formation are: Dictyophyllidites, Laeviga­ tryblium, Gonyaulacysta, Polysphaeridium, tosporites, Cheilanthoidspora, Retipilonapites, Cupu­ Lygodiumsporites, Todisporites, Cyathidites, lif ero ipolle n i te s, Rho ip i te s, Caprif oliipi tes, Proxapertites, Couperipol/is, Tricolpites and Hippocrateacidites, Margocolporites, Verrutricolpites, Palmidites. Palynotaxa restricted to the Subath u Verrucolporites, Platoniapollenites, Calophyllumpol­ Formation are: Hystrichosphaeridium, Oligosphaeri­ lenites, Kielmeyerapollenites, Polybrevicolporites, dium, Spi11ljerites, Cleistosphaeridium, Cyclonephe­ Pseudonothofagidites, etc. lium, Thalassiphora, Subathua, Araneosphaera, The following palynotaxa of the Therria Achilleoidinium, Tenua, Hexagonifera, Verrutri­ Formation are not present in the Palana Bed, colpites and Podocarpidites. The palynotaxa Rajasthan: Intrapunctisporis, Lygodiumsporites, 306 THE PAlAEOBOTANIST

Foveotriletes, Monolites, Polypodiisporites, Palmidites, Jain and Tandon (1981) described a palynologi­ Proxapertites, Assamialetes, Tricolporopollis, Densi­ cal assemblage from the Middle Eocene sediments verrupollenites, etc. In addition to this the Therria of Kutch establishing five informal zones within it. assemblage possesses many dinoflagellate cysts. The This assemblage is not closely comparable to the palynofloral assemblages of Palana beds and Therria present one as only a few elements, viz., Operculo­ Formation have very few elements in common. -Sah dinium centrocarpum, Homotryblium plectilum, and Kar (1974) assigned a Lower Eocene age to the Adnatosphaeridium vittatum, Polysphaeridium Palana beds. subtile and Cordosphaeridium are common to both the assemblages. Kutch

Cambay Basin Palynological studies on the Lower Tertiary sediments of Kutch have been carried out by Mathur The palynological reports from the Cambay (1963, 1966), Venkatachala and Kar (1968, 1969a, Basin have been published by Varma and Dangw3l 1969b), Sah and Kar (1969, 1970), Kar and Saxena (1964), Venkatachala and Chowdhary (1977), Rawat, (1976), and Saxena (1978, ·1979). Mukherjee and Venkatachala (1977), Mathur and Saxena (1978, 1979) reported a rich palyno­ Chowdhary (1977) and Mathur, Juyal and Chopra logical assemblage from the Matanomadh Formation, (1977). The palynofloral assemblage from the Kadi Kutch (Palaeocene), comprising 45 genera Formation, Cambay Basin (Venkatachala & assignable to 86 species. Of these, 14 genera and 27 Chowdhary, 1977) is not closely comparable to the species belong to pteridophytes, 3 genera and 3 present assemblage. However, the following species belong to gymnosperms and 28 genera and elements are common to both the assemblages: 56 species belong to angiosperms. Palynofossils Lygodiumsporites, Biretisporites, Verrucatosporites, common between the Matanomadh and Therria Schizaeoisporites, Palmaepollenites, Liliacidites, formations are: Cyathidites australis, Lygodium­ Proxapertites and Tricolpites. The palynotaxa present sporites eocenicus, Todisporites major, 1?andotia­ in the Kadi Formation but absent in the present spora dilata, D. telonata, Intrapunctisporis, Osmun­ assemblage are: Polypodiaceaesporites, Arecipites, dacidites, Polypodiisporites mawkmaensis, Couperi­ Mauriidites, Spinizonocolpites, Psilod/porites, Retitri­ pollis wodehousei, C. brevispinosus, C. robustus, colpites, Margocolporites, Rhoipites, Cupulijeroipol­ Liliacidites, Palmidites maxim us, Palmaepollenites, lenites and Marginipollis. The palynofossils present Proxapertites and Tricolpites. in the Therria and Kopili assemblages but not The palynotaxa present in the Matanomadh For­ recorded from. the Kadi Formation are: Cyathidites, mation but absent in the Therria Formation are: Intrapunctisporis, Couperipollis, Assamialetes, Tricol­ Dictyophyllidites, Leptolepidites, Foveosporites, Lyco­ poropollis, Todisporites, Palmidites and Lakiapollis. podiumsporites, Cicatricosisporites, Polypodiaceae­ Besides, many dinoflagellate cyst genera recorded in sporites, Dracaenoipollis, Verrutricolpites, PSilaste­ the present assemblage are also absent in the Kadi phanocolpites, Striatricolporites, Meliapollis, Formation. Venkatachala and Chowdhary (1977) Triorites, Triporopollenites, Sonneratioipollenites and assigned a Lower Eocene age to the Kadi Formation. Pseudonothojagidites. The palynofossils which are The palynological assemblage from the Kalol present in the Therria Formation but absent in the Formation, Cambay Basin (Mathur & Chowdhary, Matanomadh Formation are: Assamialetes 1977) is also not much comparable to the present emendatus, Tricolporopollis, Foveotriletes, Monolites, assemblage. The follOWing palynotaxa are common etc. In addition to this many dinoflagellate cyst -to both the assemblages: Lygodiumsporites, genera occurring in the Therria Formation are also Polypodii-sporites, Schizaeo isporites, Osmundacidi­ not represented in the Matanomadh assembalge. A tes, Striatriletes (Magnastriatites), Palmaepollenites, comparative study reveals that the palynofloral Retitrescolpites, Proxapertites and Liliacidites. The assemblages from Therria and Matanomadh palynotaxa present in the Kalol Formation but not Formation are closely comparable. represented in the present assemblage are: Glei­ The palynological assemblage from the Naredi cheniidites, Alsophilidites, Lycopodiumsporites, Bacu­ and Harudi formations, Kutch (Lower-Middle latisporites, Mauritidites, Psilatricolpites, Anacolci Eocene), described by Kar (1978), is also not closely dites, Cupulijeroipollenites, Bombacacidites, comparable to the present assemblage. Very few Rhoipites, Acanthacidites, Araliaceoipollenites, elements, viz., Cyathidites, Polypodiisporites, Palm­ Margocolporites, etc. Forms recorded in the preSent aeopollenites, Couperipollis, Proxapertites and assemblage but absent in the Kalol assemblage 'are : Dandotiaspora are common among the Naredi, In trapunctisporis, Todisporites, Assamialetes, Tricol Harudi and Therria assemblages. poropollis, Couperipollis, Pa1m idites, Tricolpites, etc. SINGH & TRIPATHI-PALYNOLOGY OF THE JAlNTIA GROUP 307

Cauvery Basin Cherra and Therria assemblages: Cyathidites, Lygo­ diumsporttes eocenicus, Foveotriletes pachyexinous,

~. The palynological studies on the Palaeocene Dandotiaspora dilata, Polypodiisporites, Monolites Eocene sediments of the Cauvery Basin have been mawkmaensis, Schizaeoisporites, Assamialetes carried out by Venkatachala and Rawat (1972). The emendatus, Couperipol/is brevispinosus, C. following palynotaxa are common to both the wodehousez~Liliacidites microreticulatus, Palmae­ assemblages: Lygodiumsporites, Schizaeoisporites, pollenites communis, Proxapertites assamicus, Proxapertites, CouperipoUis, Palmaepol/enites, Tricolpites, Sciadopityspollenites, Tricolporopollis Liliacidites, Tricolpites and Myriczpites. The rubra, etc. palynotaxa present in the Cauvery basin' but absent The palynotaxa recorded in the Cherra in the present assemblage are: Laevigatosporites, Formation but absent in the present assemblage are: Spinainaperturites, Psilodzporites, Marginzpollis, Stereisporites, Lycopodiumsporites, Sestrosporites, Palaeoc aesalpin iaceaepites, Margocolporites, Retzpilonapites, Polycolpites, Nyssapollenites, Rhoipites, Capnjolizpites, etc. Tnporopollenites, Meliapollis, Foveosporites, Micro­ The palynotaxa occurring in the present reticulatisporites, Foraminisporis, etc. The assemblage but absent in the Cauvery Basin palynomorphs present in the Therria Formation but , assemblage are: Cyathidites, fntrapunctisporis, not represented in the Cherra Formation are: Dandotiaspora, Todisporites, Osmundacidites, fntrapunctisporis, Dandotiaspora telonata, Assamialetes, Palmidites, Tricolporopollis, Lakia­ Todisporites, Palmidites plicatus, etc. Besides these pollis, etc. many dinoflagellate cyst genera recovered from the Therria Formation are also absent in the Cherra Basin Formation. It is observed that the Therria and Cherra assemblages are closely comparable. The Cherra Baksi (1972) carried out a detailed palynostrati Formation is of Palaeocene age (Dutta & Sah, 1970). graphiC work on the Upper and Tertiary The palynological assemblage from the Tura succession of the Bengal Basin dividing it into seven Formation, Meghalaya described by Singh (1977a) palynological zones. comprises 53 spore-pollen genera referable to 89 The sediments in the Bengal Basin range from species. Out of these, 19 genera and 29 species Middle to Plio-Pleistocene in age. The belong to pteridophytes and 34 genera and 69 Zone II and Zone III are of Palaeocene to Early species belong to angiosperms. The palynotaxa Eocene and Middle to Late Eocene ages respectively. common to the Tura and Therria assemblages are: The Zone II and Zone III have some palynofossils Cyathidites, Lygodiumsporites eocenicus, Foveotri­ which also occur in the present assemblage. These letes pachyexinous, Dandotiaspora dilata, D. are: Assamialetes emendatus, Palmaepollenites and telonata, Monolites discordatus, Monolites Couperipollis. A comparative study reveals that the mawkmaensis, Assamialetes emendatus, Bengal Basin palynoassemblage is not comparable to Couperipol/is brevispinosus,c. wodehousei, Liliaci­ the present assembalge except for the common dites microreticulatus, Palmaepollenites communis, occurrence of a few elements. Proxapertites assamicus, Liliacidites major, L. giganticus, Palmidites maxim us, etc. The palynotaxa Assam Basin occurring in the Tura Formation but absent in the Therria Formation are: Stereisporites, Lycopodium­ The palynological studies in the Lower Tertiary sporites, Retzpilonapites, Polycolpites, Nyssapollenites, sediments of Assam and Meghalaya have been Tnporopollenites, Triorites, Meliap0 llis, Droseridites, carried out by Biswas (1962), Baksi (1962), Sah and Pseudonothojagidites, etc. The palynomorphs Dutta (1966, 1968, 1974), Duna and Sah (1970), Sah, present in the Therria Formation but absent in the Kar and Singh (1970), Salujha, Kindra and Rehman Tura Formation are: fntrapunctisporis, Sciadopity (1972, 1974), Salujha, Rehman and Kindra (1973), spollenites, Tricolpites alveolatus, Retisyncolporites, Sah and Singh (1974), Sein and Sah (1974), Singh Tricolporopollis rubra, etc. It is apparent from the (1977a, 1977b), Singh and Tiwari (1979), Dutta and above mentioned comparative study that the Tura Jain (1980) and Mehrotra (1981). Dutta and Sah and Therria assemblages are closely comparable. Sah (1970) described a rich palynological assemblage and Singh (1974) assigned a Palaeocene age to the from the Cherra Formation, Meghalaya. It comprises lower part of the Tura Formation. 49 genera assignable to 103 species. Out of this 18 Duna and Jain (1980) recorded a rich dinofla­ genera and 34 species belong to pteridophytes, one gellate cyst assemblage from the Upper Palaeocene­ genus and one species to gymnosperm and 27 Upper Eocene sediments of the Jaintia Hills, genera and 68 species belong to angiosperms. The Meghalaya. The forms common to both the assemb­ following palynotaxa are common between the lages are as follows: Turbiosphaera, Cordosphaeri- 308 THE PAlAEOBOTANIST dium exilimurllm, C. mlillispinosum, Operculodi­ QUANTITATIVE ANALYSIS OF THE nium cenlrocalplIm, O. major, Homolryblium PALYNOFLORA pleclilum, Apeclodinium homomorphum and A. parvum. The dinoflagellate cysts occurring in the The percentage frequency of various palynotaxa assemblage described by Dutra and Jain (1980) but has been determined by counting 200 palynofossils absent in the present assemblage are: Thalassiphora per sample but in some cases where the yield was Dislalodinium, Samlandia, Araneosphaera, poor 150 palynofossils were counted. Out of 59 Hyslrichokolpoma, Spinijel-iles and Claphyrocysla. genera and 92 species, 26 genera assignable to 48 The dinoflagellate cysts occurring in the present species were found to be stratigraphically assemblage but absent in the assemblage described significant. by DUlla and Jain (1980) are: Conyaulacysla, The quantitative analysis of the palynofloraI Apleodinium, Prolixosphaeridium, Polysphaeridium, assemblage reveals that the lower part of the Therria Adnalosphaeridium and Codoniella. A comparative Formation is dominated by the pteridophytic spores, study shows that the two assemblages are closely particularly the genus Lygodiumsporiles. The middle comparable. part of the Therria Formation is characterized by the predominance of angiospermic pollen grains, Dandot (Pakistan) whereas its upper part is richly dominated by the dinoflagellate cysts. The Sylhet limestOne has Vimal (1952) described a palynological yielded very few palynofossils, hence, it has not assemblage from Dandot Lignite, Pakistan been possible to observe any palynofloral change comprising 29 spore/pollen types assignable to 10 wllhin this formation. genera. The forms appearing to be common between In the Kopili Formation the lower part is the two assemblages are: Dandoliaspora dilala dominated by the dinoflagellate cysts while the (=Trililes spm. 6), Dandoliaspora lelonala (=Trililes upper part is characterized by the high frequency of spm. 6) and Lygodiumsporiles eocenicus (= Trililes pteridophytic spores. The genus Slrialrileles is spm. 4). The common occurrence of these forms characteristically associated with this Formation. favours the dating of Dandot Formation as Palaeo­ On the basis of qualitative and quantitative cene. analyses of the palynoflora recovered from the Palaeocene- Eocene sediments exposed along the road between Jowai and Sonapur, Meghalaya, Australia and New Zealand Tripathi and Singh (1984b) established five palynozones which are given below in ascending The Lower Tertiary palynological assemblage of order of stratigraphy (Text-fig. 1). New Zealand (Couper, 1953, 1958) and Australia KaPIL! FORMATION: (Cookson, 1946, 1947; Cookson & Pike, 1954) are dominated by the pollen grains of NOlhojagus, Cupe­ 5. Densiverrupolleniles eocenicus Cenozone Tripathi nidiles, Podocalpus, etc. These forms are absent in & Singh (1984b) the present assemblage. However, some pollen 4. Turbiosphaera proximala Cenozone Tripathi & grains, viz., Palmidiles maximus, Cyalhidites Singh (1984b) australis, Tricolpiles alveolalus, Couperipollis and THERRIA FORMATION: Liliacidiles are common between the New Zealand and Therria assemblages. Wilson (1967) described 3. Apectodinium homomorphum Cenozone Tripathi Apectodinium (Wetzeliella) from the Palaeocene­ & Singh (1984b) Eocene strata of New Zealand. This form has also 2. Palmidiles oblusus Cenozone Tripathi & Singh been recorded in the Therria assemblage. The (1984b) Australian Palaeocene- Eocene dinoflagellate cyst Lygodiumsporiles psilailis Cenozone Tripathi & assemblages are dominated by Apeclodinium Singh (1984b) (Wetzeliella) and Dejlandrea. The genus Dejlandrea is not present in the present assemblage. PALAEOECOLOGY, PALAEOGEOGRAPHY AND A world wide palynofloral comparison of the ENVIRONMENT OF DEPOSITION Palaeocene- Eocene assemt-alges reveals that the present assemblage is partially comparable to the The palynological assemblage recovered from palynoflora of south-east Asian countries, Austrialia, the Palaeocene- Eocene sediments, exposed along New Zealand and western European countries. The the road between Jowai and Sonapur, Meghalaya is dinoflagellate cyst assemblage is strikingly similar to represented by many pteridophytic and the one described from the London Clay (Eocene) of angiospermic families which are presently restricted Britain. to the tropical to subtropical regions of the world. SINGFI & TRIPATHI-PALYNOLOGY OF THE JAINTIA GROUP 309

JAINTIA ( PALAEOCENE - EOCENE) GROUP LEGEND o SANDSTONE THERRIA SYLHET KOPILI FORMATION .... ~ SHALE I :;i..:LITHOLOGY I ~ LIMESTONE .···.....•·...·\III)/!::I'!:I••·.·1/!:I\?It!: I I.· _ COAL :.:.~>1 "'I::!II" t. '<::J::.J: ::':«'1 iIi:; I ><> I I iu >r.,: t: ______CYATHIDITES AUSTRALIS INTRAPUNCTISPORIS DENSIPUNCTIS, FIG. 7 LYGODIUMSPORITES MARGINIPLICATUS, FIG 8 LYGODIUMSPORITES PSILATUS ,FIG.1S COUPERIPOLLIS WODEHOUSEI ,FIG. 23 L1L1ACIDITES MICRORETICULATUS FIG. 21 LADAKHIPOLLENITES ELONGATUS CORDOSPHAERIDIUM VALIANTUM LYGODIUMSPORITES MEGHALAYAENSIS,FIG. S LYGODIUMSPORITES KHLlEHRIATENSIS,FIG 9 COLLOSPERMUMPOLLIS lAEVIGATUS. FIG.13 PROXAPERTITES ASSAMICUS, FIG.11 L1L1ACIDITES MAJOR PALMAEPOLLENITES COMMUNIS COUPERIPOLLIS BREVISPINOSUS L1L1ACIDITES GIGANTICUS COUPERIPOLLIS MEGHALAYAENSIS. FIG. 1 ASSAMIALETES EMENDATUS, FIG. 18 LYGCDIUMSPORITES EOCENICUS, FIG.19 DANDOTIASPORA DILATA. FIG.17 PALMIDITES MAXIMUS PALMIDITES OBTUSUS, FIG. 4 APECTODINIUM HOMOMORPHUM. FIG. 22 APECTODINIUM PARVUM, FIG. 3 HOMOTRYBLIUM OCEANICUM OPERCULODINIUM ISRAELIANUM TRICOLPITES ALVEOLATUS OPERCULODI NIUM MAJOR OPERCULODINIUM CENTROCARPUM TODISPORITES MAJOR DANDOTIASPORA TELONATA, FIG. 6 TRICOLPOROPOLLIS RUBRA ADNATOSPHAERIDIUM ROBUSTUM POLYSPHAERIDIUM SUBTILE HOMOTRYBLIUM TENUISPINOSUM CODONIELLA LANGPARENSIS ADNATOSPHAERIDIUM VITTATUM CORDOSPHAERIDIUM MULTISPINOSUM TURBIOSPHAERA FILOSA TURBIOSPHAERA PROXIMATA. FIG 20 POLYSPHAERIDIUM GIGANTEUM S TRIATRILETES SUSANNAE. FIG. , 2 LAKIAPOLLIS ASSAMICUS, FIG. 2 HOMOTRYBLIUM PLECTILUM STRIATRILfTES ATTENUATUS, FIG. 14 STRIATRILETES PSEUDOCOSTATUS, FIG. 16 DENSIVERRU POLLENITES EOCENICUS,FIG 10 ~ -I Ul oJ> C 'U o 'U o~'U O'U::O rrJ ~'UUl'­rrJoJ> rrJorrJ ",;;olD Q ZUl'U< ZlD'; z.,.o z06 ", oj=oGl o-l:=: 0""-1 OXUl Ul ~~~~NCO NOO N~'U 0 :x: ZC rrJC oUl- 0::00 rTlUlUl~ Z~~ Z~z Z~J> rrJ Ul rrJ rrJJ>rrJ I cc ~ ~ ~

~, ,C:

·i~\:'-....: ...... ,.....~~. <. ~~" ~ ~

Te:\."!·figure I-Palynological zonation of the Palaeocene-Eocene strata Oawai·Sonapur), Meghalaya (Litholog nor to the scale). 310 THE PALAEOBOTANIST

f'hese families are: Lycopodiaceae, Polypodiaceae, southern part of the ]aintia Hills. Simultaneously the .)chizaeaceae, Cyatheaceae, Parkeriaceae, Palmae, area started withdrawing from the Shillong Plateau Liliaceae, Nymphaeaceae, Nelumboniaceae, (Singh, 1977b). The continued subsidence of the Oleaceae and Myricaceae. Besides, other families southern slope of the Shillong Plateau is indicated represented in the assemblage are cosmopolitan in by the huge thickness of the strata exhibited by the the present day distribution. Sylhet Limestone and Kopili formations. The Lakhanpal (1970), on the basis of the transgression of the sea in this area is evidenced by palaeobotanical evidences, envisaged that the the presence of dinoflagellate cysts in these Palaeogene flora in the was sediments. The Palaeocene-Eocene sediments predominantly tropical. The fact that tropical to exposed along the road berween ]owai and Sonapur, subtropical vegetation was existing in the nearby Meghalaya appear to have been deposited under the areas of Assam and Meghalaya has been confirmed brackish water to shallow marine environments. by the palynological studies (Duna & Sah, 1970; Sah The oldest sediments of the Therria Formation, & Singh, 1974; Singh, 1977a, b). The present represented by the Lygodiumsporites psilatus palynological evidences also indicate that the area in Cenozone, is characterized by the dominance of the the vicinity of Meghalaya was supported by a tropical pteridophytic spores (47%) and angiospermic pollen to subtropical flora grains (38%). The dinoflagellate cysts are ~ The climate during the deposition of the represented by 7 per cent of the total assemblage of \ investigated Palaeocene-Eocene sediments of the cenozone. The Palmidites obtusus Cenozone of Meghalaya was warm and humid. This view is the Therria Formation is dominated by the supported by the presence of many fungal remains angiospermic pollen grains (47%) and pteridophytic in the palynological assemblage recovered from this spores (24%). The dinoflagellate cysts are area. Amongst fungal remains the frUiting bodies like represented by 25 per cent of the total cenozone Callimothallus, Phragmothyrites and Paramicrothal­ assemblage. The youngest palynological zone of the lites, belonging to the epiphyllous fungi, are very Therria Formation, viz., Apectodinium common. The frequent occurrence of these fruiting homomorphum Cenozone is dominated by the bodies suggests that a warm and humid climate dinoflagellate cysts (78%). Here the angiospermic prevailing during that period supported a vegetation pollen grains and the pteridophytic spores are favourable for the growth of the epiphyllous fungi. A represented by 17 per cent and 4 per cent similar palaeoclimate has been deduced for the respectively. Cherra (Duna & Sah, 1970) and Tura formations (Sah Therefore, it is clear that the older sediments of & Singh, 1974). the Therria Formation exhibit comparatively low As mentioned earlier the Tertiary sediments in percentage frequency of the dinoflagellate cysts r the area of investigation rest unconformably over the while, its younger sediments are characterized by a Precambrian Shillong Group. This indicates that the very rich representation of the dinoflagellate cysts. area remained a high ground during the Palaeozoic This perceptible change in the palynological and Mesozoic times but finally got submerged into spectrum of the Therria Formation indicates that the the water by the close of the Mesozoic Era paving a sediments representing the Lygodiumsporites way for the deposition of Tertiary sediments. psilatus and Palmidites obtusus cenozones were Singh (1977b) mentioned that the Garo, Khasi, deposited under the brackish water estuarine ]aintia and Mikir Hills, comprising the Assam conditions, whereas the sediments representing the autochthon, were initially a north-easterly extension Apectodinium homomorphum Cenozone were of the Peninsular India and they got detached from deposited under shallow marine conditions. the mainland sometimes during the Cretaceous In the Kopili Formation the older Turbiosphaera Period. The break up of the Gondwanaland during proximata Cenozone is characterized by the that time upset the isostatic balance of the region dominance of the dinoflagellate cyst assemblage causing varieus earth movements. The Dauki Tear (44%). The pteridophytic spores and angiospermic Fault, which crosses the ]owai-Badarpur Road near pollen grains are collectively represented by 16 per Sonapur, appears to be attributed to one of these cent of the total assemblage. The youngest movements. These earth movements also seem to be palynozones of the Kopili Formation, viz., responsible for the subsidence of the southern Densiverrupollenites eocenicus Cenozone exhibits slopes of the Garo, Khasi and ]aintia Hills (Singh, the dominance of the pteridophytic spores (40%) 1977b). and angiospermic pollen grains (7%) over the It appears that the gradual sinking of the dinoflagellate cysts (10%). southern slope of the ]aintia Hills, Meghalaya was The palynological spectrum of the Kopili probably associated with the rise of the Shillong Formation indicates that the sediments representing Plateau. This caused the invasion of the sea in the the Turbiosphaera proximata Cenozone were SINGH & TRIPATHI-PALYNOLOGY OF THE JAiNTIA GROUP 311

deposited under shallow marine conditions, while 1. Cherra Formation is disconformably underlain by the sediments representing- the Densiverrupollenites Langpar Formation which is supposed to be Danian eocenicus Cenozone were deposited under brackish in age. It shows the presence of foraminifera like ... water estuarine conditions. The Kopili Formation Globigerina pseudobulloides and Globigerina trilo­ sediments appear to have been deposited under the culinoides, etc. These forms are characteristic of the shallow sea which was subjected to frequent Danian age. oscillations. This view is supported by the alternate 2. Cherra Formation is conformably overlain by the deposition of the shales and sandstones in this Lakadong Limestone Member of the Sylhet formation (Dutta & Jain, 1980). Limestone. This member has yielded typical Ranikot Coastal conditions prevailing during the time of (Lower Eocene) like Nummulites thalicus, N. deposition of the investigated Palaeocene-Eocene sindensis, Lockhartia hamei, Miscellania miscella, M. sediments is proved by the rich representation of the meandrina, Operculina cf. canalifera, Alveolina sp., pollen grains resembling those of the family Palmae. Orbitospiphon tibetica and Discocyclina These pollen grains are: Palmidites maxim us, P. ranikotensis. obtusus, P. plicatus, Palmaepollenites communis, Therefore, the Cherra Formation between the Coupenpollis brevispinosus, C. meghalayaensis, C. underlying Langpar Formation (Danian) and wodehousei and C. rarispinosus. The fresh water overlying Lakadong Limestone Member (Lower elements represented in the palynoassemblage, viz., Eocene) was dated by Dutra and Sah (1970) as Proxapertites assamicus and Assamialetes emendatus Palaeocene. The palynofossils common to the appear to have been transported to the near-shore Therria Formation and Cherra Formation are: areas through the fresh water channels which might Cyathidites australis, Lygodiumsporites eocenicus, have had connections with the sea then. The coastal Corrugatisporites, Foveotriletes pachyexinous, vegetation seems to have been followed by the Monolites mawkmaensis, Polypodiisporites swamp vegetation. The presence of swamp mawkmaensis, Schizaeoisporites, Sciadopityspolleni­ vegetation is supported by the pollen grains of the tes, Assamialetes emendatus, Trifossapollenites family Chenopodiaceae, viz., Polyporina sp. constatus, Couperipollis (Monosulcites) brevispino­ sus, C. (monosulcites) rarispinosus, Liliacidites microreticulatus, Proxapertites (Schizosporis) AGE OF THE THERRIA FORMATION assamicus, Retitrescolpites, Myricipites and Formation, Polyporina. It is apparent from comparisons of the palyno­ The earlier workers like Oldham (1863), floras of Therria and Cherra formations that many -"- ,. Medlicott (1869), La Touche (1887), Medlicott and spore and pollen genera are common between the Blanford (1893), and Pinfold (1919) assigned a two. Hence, it is logical to assume that both these Cretaceous age to the Tura Formation (= Therria and formations are time eqUivalents. Therefore, on the Cherra formations). Evans (1932), while dealing basis of the palynological similarities between the with lithostratigraphy of Tertiary sediments in Assam Cherra and Therria formations, Palaeocene age has assigned a Lutetian (Middle-Eocene) age to most of been assigned to the Therria Formation. the Jaintia Group sediments. The basal sedimems of Palaeocene dating of Therria Formation is this group are represented by Therria Formation. Fox further supported by the fact that, its YOungest (1936) also expressed the view that the Tura palynozone, viz., Apectodinium homomorphum Formation (= Therria Formation) may belong to the Cenozone is characterized by the presence of Lower Tertiary age. The Tertiary age for these Apectodinium homomorphum and A. parvum. These sediments was later confirmed by Jacob (1949) and forms are considered to be characteristic of Upper Pascoe (1963), Sah and Dutra (1966,1968) and Dutta Palaeocene age (Harland, 1979). The presence of and Sah (1970). these palynofossils in various Upper Palaeocene Langpar Formation, which represents lowermost sediments has been reported by Cookson (1967), Tertiary sediments in Assam Basin, is overlain by a Wilson (1967) and Chateauneuf and Gruas-Cavag­ coal measure sequence. This sequence has been netto (1978). named as Therria Formation along the Sah and Singh (1974) correlated three lower Umshoryngkew River, Cherra Formation in palynozones of Tura Formation, viz., Assamialetes Cherrapunji Plateau, Tura Formation in emendatus Cenozone, Dandotiaspora telonata and Mikir Formation in Mikir Hills. Dutta and Sah Cenozone and Palmidites plicatus Cenozone with (1970) and Sah and Dutta (1974) recovered a rich the three palynozones of Cherra Formation, viz., palynological assemblage from Cherra Formation Proxapertites erassimurus Cenozone, Araliaceoi­ and proposed Palaeocene age for it. The Palaeocene pollenites reticulatus Cenozone and Tricolpites age for this formation was indicated by these authors reticulatus Cenozone respectively and assigned a on the basis of the follOWing evidences. Palaeocene age to these Tura sediments. 312 THE PAlAEOBOTANIST

AGE OF KOPILI FORMATION Couper, R. A. 1958. British Mesozoic microspores and pollen grains. A systematic and stratigraphic study. PaiaeonlO· As mentioned earlier no detailed palynostrati· graphica 103B : 75·179. Dutta, S K & Sah, S. C. D. 1970. Palynostratigraphy of the Tertiary graphical work has been carried out on the KopiJi sedimentary formations of Assam. 5. Stratigraphy and palyno· Formation, Meghalaya, on the basis of which any logy of South Shillong Plateau. Palaeontographica 131B(1-4) : precise date could be given to this formation. 1·62. Samanta (1968) on the basis of presence of small Dutta, S. K & Sah, S C. D. 1974. Palynostratigraphy of the sedi· foraminifera Jike Pellatispira and absence of mentary formations of Assam, India. 4. Age of the Laitryngew. Mawkma coal bearing sandstOnes and their relationships characteristic Middle Eocene forms like Assilina, with the Cherra Formation. Palaeobotanist 21(1) : 48·51. Alveolina, Dictyoconoides and Lockhartia confirmed Dutta, S. K. & Jain, K. P. 1980. and palynology of the area an Upper Eocene age for this formation. Sein and around Lumshnong, Jaintia Hills, Meghalaya, India. Bio/. Sah (1974) and Dutra and Jain (1980) did not assign Mem. 5(1): 5681 Evans, P 1932. ExplanatOry notes to accompany a table shOWing any age to Kopili Formation. Their palynological the Tertiary succession in Assam Trans. min. geo/ Insl India assemblages lack any Upper Eocene stratigraphical 270) : 155·260. marker. The present Kopili assemblage also lacks Fox, C. s. 1936. (in L. L.Fermor, 1934) DirectOr's General Report. any Upper Eocene marker form. Archangelsky (1969) Rec. geol. Surv. India 69( I) : 82·84. described Turbiosphaera from the Rio·Turbio Harland, R. 1979 The Wetzeliella (Apectodinium) homomorphum plexus from the Palaeocene·earliest Eocene of northwest (Lower Eocene'Upper Eocene) of Santa Cruz Europe. IV. int palynol. Con/., Lucknow (J 976· 77), 2 : 59·70. Province, Argentina. This form has also been Birbal Sahni Institute of Palaeobotany, Lucknow. recovered from Lower palynological zone of Kopili Jacob, K. 1949. Director's General Report for 1948. Rec. geol. Surv. Formation, viz., Turbiosphaera proximata Cenozone India 82( 1) : 73. Therefore, occurrence of Turbiosphaera in Kopili Jain, K. P., Kar, R. K & Sah, S. C. D. 1973. A palynological assemb· Formation may prove helpful in its dating at a later lage from Barmer, Rajasthan. GeophylO/ogy 3(2): 150·165. Jain, K P. & Tandon:K K. 1981 Dinoflagellate and acritarch bio· date by carrying Out detailed study of this genus up stratigraphy of the Middle Eocene rocks of a part of South· to the specific level. However, Kopili Formation is western Kutch, India. ]. Palaeontol. Soc. India 26 : 6·21. dated as Eocene on palaeontological eVidences. Kar, R. K 1978. 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Point Formation, southwestern VictOria: Part 1. Proc. R. Soc. Oldham, T 1863. Notes on the structure of the 'parts of the Khasi Vict. (n. ser.) 79(2) : 139·146 Hills. Mem. geol. Surv. India 1 : 99·210. Cookson, 1. c.,& Pike, K M. 1954. Some dicotyledonous pollen Pascoe, E. H. 1963. A Manual of and Burma types from Cainozoic deposits in Australian region. Ausl I Bot. 2(2) . 197219. 3: 1345·2130. Pinfold, E. S 1919 Two new fossil localities in the Garo Hills. Rec. Couper, R. A. 1953 Upper Mesozoic and Cainozoic spores and pollen grains from New Zealand. Bull. N. Z. geol. Sum geol. Sum India 50(2) : 126·129. Palaeonl 22 : 1·77 Rao, A. R & Vimal, K. P. 1950. Plant microfossils from Palana Lig SINGH & TRIPATHI-PALYNOLOGY OF THE )AINTIA GROUP 313

nite (Eocene), Bikaner. Curro Sci. 19: 82-84. marginal sediments of , India. IV int Rao, A. R. & Vimal, K. P. 1952. Tertiary pollen from lignites from palynol. Con/., Lucknow (J 976-77) 2 : 462-471. Birbal Sahni Palana (Eocene), Bikaner. PrOC. nam. Inst. Sci. India 18(6) : Institute of Palaeobotany, Lucknow. ~ 595601. Singh, H. P., Khanna, A. K. & Sah, S. C. D. 1978. Palynological Rawat, M. S., Mukerjee,J. & Venkatachala, B. S. 1977. Palynology of zonation of the Subathu Formation in the Kalka Simla area the Kadi Formation, Cambay Basin, India. Proc. 4th Colloq. of Himachal Pradesh. Him. Geo/. 8 : 33-46. Indian MicropaJaeont_ Srratigr., Dehradun: 179-192 Singh, H. P. & Tripathi, S. K. M. 1983. A comparative study of Sah, S. C. D. & DUlla, S. K. 1966_ Palynostratigraphy of the sedi­ spores of Ceratopteris thalietroides (L) Brong. and Str/atri· mentary formations of Assam-I. Stratigraphical position of the letes van der Hammen emend. Kat. Geophytology 13(2) . Cherra Formation. Palaeobotanist 15(1 -2) : 72·86. 219-226. Sah, S. C. D. & DUlla, S. K. 1968. Palynostratigraphy of the Tertiary Singh, H. P. & Tripathi, S. K. M. 1986. Observations on some formations of Assam·2. Stratigraphic significance of spores Tertiary zonisulcate pollen grains. Palaeobotanist 35(1) . and pollen in the Tertiary succession of Assam. Palaeobota· 48-52. nist 16(2) : 177-195. Singh, R Y. 1977a. Stratigraphy and palynology of the Tura Forma· Sah, S. C. D. & DUlla, S. K. 1974. Palynostratigraphy of the sedi· tion in the rype area-part 11. (Descriptive Palynology). Palaeo· mentary formations of Assam·3. Biostratigraphic zonation of botanist 23(3) : 189-205. the Cherra Formation of South Shillong Plateau. Palaeobotanist Singh, R. Y. 1977b. Stratigraphy and palynology of the Tura 21(1) : 42-47. Formation in the rype area (part 111) : Discussion. Palaeobo· Sah, S. C. D. & Kar, R. K. 1970. Palynology of the Laki sediments in tanist 24(1) : 1-12. Kutch· 3. Pollen from the boreholes around jhulari, Baranda Singh, R. Y. & Tewari, B. S. 1979. A note on the palynostratigraphy • and Panandhro. Palaeobotanist 18(2): 127·142. of the Tertiary sediments of Upper Assam. Bull. Indian Geol Sah, S. C. D., Kar, R. K. & Singh, R. Y. 1970. Fossil microplankton Assoc. 12(2) : 151·159 from the Langpar Formation of Therriaghat, South Shillong Singh, T C. N. & Natarajan, A. T. 1950. Angiosperm remains from Plateau, Assam, India. Palaeobotanist 18(2) : 143·150. the Barmer sandstones. Curro Sci. 19 : 124-125. Sah, S. C. D. & Singh, R. Y. 1974_ Palynological biostratigraphy of Tripathi. S. K. M. (in press). Algal and fungal remains from the the Tura Formation in rype area, pp. 76·98 in Sah, S. C. D. Jowai·Sonapur Road Section (Palaeocene-Eocene), Meghalaya, (Ed. )-Symp. Stratigr. PaIyn01. Birbal Sahni Institute of India. Palaeobotanist. Palaeobotany, Lucknow. Tripathi, S. K. M. & Singh, H. P. 1984a. Two new pollen genera Salujha, S. K., Kindra, G. S. & Rehman, K. 1972. Palynology of the from the Lower Tertiary sediments of Meghalaya, India. South Shillong Front part· 1 : The Palaeogene of Garo Hills. Palaeobotanist 32(2): 153-157. Proc. Sem. palaeopalynol. Indian stratigr. : 265·291. Tripathi, S. K. M. & Singh, H. P. 1984b. Palynostratigraphical zona­ Salujha, S. K., Kindra, G. S. & Rehman, K. 1974. Palynology of the tion and correlation of the Jowai·Sonapur Road Section South Shillong Front: Part II·The Palaeogenes of Khasi and (Palaeocene· Eocene), Meghalaya, India Proc. V Indian geo­ jaintia Hills. Palaeobotanist 21(3) : 267-284. phytol. con/., Lucknow (J 983) Salujha, S. K., Rehman, K. & Kindra, G. S. 1973. Distinction Tripathi, S. K. M. & Singh, H. P. 1985. Palynology of the ]aintia between Bhuban and Bokabil sediments on the southern Group (Palaeocene-Eocene) exposed along Jowai Sonapur edge of Shillong plateau based on palynofossil assemblages. Road, Meghalaya, India, (Part I). Systematic palynology_ Bull. 0. N G. C. 10(1·2): 109-117. Geophytology 15(2) : 164-187 Salujha, S. K., Srivastava, N. C. & Rawat, M. S. 1969. Microfloral Varma, C. P. & Dangwal, A K. 1964. Tertiary hystrichosphaerids assemblage from Subathu sediments of Simla Hills. j. Palae­ from India. Micropaleontology to( J) . 63· 71. ont. Soc. India 12 : 25·40. Venkatachala, B. S. & Chowdhary, L. R. 1977. Palaeoecology of Samanta, B. K. 1968. The Eocene succession of Garo Hills, Assam, Kadi Formation, Cambay Basin, India. Proc. 4th Colloq_ India. Geol. Mag. 105(2): 124-135. Indian Micropaleont. Stratigr., Dehradun 259-277 Saxena, R. K. 1978. Palynology of the Matanomadh Formation in Venkatachala, B. ·S. & Kar, R. K. 1968. Fossil pollen comparable to rype area, north-western Kutch, India (Part-I). Systematic pollen of Barringtoma from the Laki sediments of Kutch description of pteridophytic spores. Palaeobotanist 25: Pol/en Spores 10(2) : 335-339. 448-456. Venkatachala, B. S. & Kar, R. K. 1969a. Palynology of Tertiary sedi· Saxena, R. K. 1979. Palynology of the Matanomadh Formation in ments of Kutch-I. Spores and pollen from bore-hole no 14. rype area, north-western Kutch, India (part-2). Systematic Palaeobotanist 17(2): 157·178. description of gymnospermous and angiospermous pollen Venkatachala, B. S & Kar, R. K. 1969b. Palynology of the Tertiary grains. Palaeobotanist 26(2) : 130-143. sediments in Kutch-2. Epiphyllous fungal remains from the Saxena, R_ K. & Tripathi, S. K. M. 1982. Lithostratigraphy of the bore-hole no. 14. Palaeobotanist 17(2) : 179-183 Tertiary sediments exposed along Jowai-Badarpur Road in Venkatachala, B. S. & Rawat, M. S. 1972. Palynology of Tertiary Jaintia Hills (Meghalaya) and Cachar (Assam). Palaeobotanist sediments in Cauvery Basin-I. Palaeocene-Eocene palynoflora 20(1) : 34-42 from the subsurface. ProC. Sem. Palaeopalynol. Indian Stratigr: Sein, M. K. & Sah, S. C. D. 1974. Palynological demarcation of 292-335. Eocene-Oligocene sediments in the jowai-Badarpur Road Vimal, K. P. 1952. Spores and pollen from Dandot, West Punjab Section, Assam, pp. 99-105 in Sah, S. C. D. (Ed. )-Symp. (Pakistan). Proc Indian Acad. Sci. 36 : 135-147. Stratigr. PaIyn01. Birbal Sahni Institute of Palaeobotany, Wilson, G. J. 1967. Some~ species of Wetzeliella Eisenack (Dino· Lucknow. phyceae) from Zealand Eocene and Palaeocene strata. Singh, H. P. & Khanna, A. K. 1980. Palynology of the Palaeogene New Zealand}. Bot. 5(4) : 469·497.