bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palynology of the Siwalik sediments of Kala Amb-Nahan area in Sirmaur District, Himachal Pradesh
Authors: Saxena R.K. , Bhattacharya A.P. 
Published: September 2022

The palynoflora recovered from the Lower Siwalik (Nahan) and Upper Siwalik sediments exposed along the road sections in Kala Amb-Nahan area in Sirmaur District consists of 18 genera and 25 species. Of these, two species are new. The diagnoses of two palynogenera, viz., Inaperturopollenites and Inapertisporites, have been emended. One new combination has also been proposed.
The Lower Siwalik (Nahan) palynoflora is represented by 13 genera and 17 species of fungal remains (13%), pteridophytic spores of Cyatheaceae and Polypodiaceae (5%), gymnospermous pollen of Pinaceae (73.5%), and angiospermous pollen of Liliaceae and Myricaceae (8.5%). On the other hand, the Upper Siwalik assemblage is represented by 11 genera and 15 species of fungal remains (14%), gymnospermous pollen of Pinaceae (67%), and angiospermous pollen of Potamogetonaceae, Palmae, Poaceae and Magnoliaceae (19%). A comparison of these Lower and Upper Siwalik assemblages with the known assemblages from the corresponding horizons has been made and it has been observed that the Lower Siwalik assemblage comes closest to that described from the Bhakra-Nangal Section in Himachal Pradesh, whereas the Upper Siwalik assemblage is comparable to the Pinjor assemblage near Chandigarh and Assemblage-1 of Hoshiarpur-Una Road Section assemblage.
Permian - Triassic boundary in the Peninsula
Authors: Shah S.C. 
Published: September 2022

The boundary between the Permian and Triassic systems is still a matter of controversy. The traditional view is that the base of the Otoceras beds marks the base of the Triassic and hence the top of the Permian. Though the basal Triassic is known, the topmost marine Permian is still to be recorded; this gap is not even represented by the non-marine sequence of rocks either in extra-peninsular India or in Salt Range, Pakistan.
In peninsular India, there is an undoubted non-marine (continuous) succession of Upper Permian and Lower Triassic age and no marine beds or intercalations are known. Similarly, from the extra-peninsular India, no terrestrial elements are known from the Upper Permian and Lower Triassic. Hence, the equivalence of the non-marine biozone to that of the marine is not known; only broad generalizations can be made.
The biota known from the non-marine Gondwana Sequence of Upper Permian and Lower Triassic are plants (mega as well microfloral elements), vertebrates and invertebrates are known from the Upper Permian but are so few in number, that these cannot be taken for discussion on Permian-Triassic boundary problems.
On reviewing the biota in the various peninsular basins, the Damodar Basin is considered significant for the problem of Permian and Triassic boundary. In the Raniganj Coalfield five sections, namely, Tatulakh, MAchkunda Jhor, Banspatelli, Nunia Nala and Nunia Khal have been studied extensively.
Summarizing, the following points are worth notice:

There was a peak development of the Glossopteris Flora in the upper part the Raniganj Formation. Normally, the peak development takes place just before the extinction. The complete extinction does not rule out the lingering of older forms.
The appearance of Lepidopteris and the small forms of Dicroidium is noted in the basal Panchet.
Glossopteris though became extinct at the lower altitudes has probably withdrawn to the higher altitudes, the climatic conditions of which were more akin the lower level. Dicroidium also was thriving simultaneously at higher altitudes at that time.
Higher up in the sequence but in the lower altitudes, Lystrosaurus and Estheriella
The miofloral zonations with respect to Raniganj and Panchet formations particularly with respect to Lystrosaurus zone, Estheriella Zone, Lepidopteris Zone are to be noted.

In the light of all the above considerations, the problem of the Permian and Triassic boundary is being reviewed.
Palynological correlation of Lower Gondwana coal seams
Authors: Bharadwaj D.C. 
Published: September 2022

Correlation of coal seams which is universally accepted terse geological problem, has been enunciated in all its aspects. The physical and chemical characteristics which are unpredictably variable in coal seams have been evaluated vis-a-vis their palynological characteristics which are almost constant qualitatively. These are suggested to be used for typification of each coal seam or its lithological equivalent so as to trace its lateral extension through correlation of the bits and parts occurring in various sectors of the coalfield. As example of palynotypification, two, recently studied two coal seams from Talcher Coalfield have been illustrated. One of them is the basal seam in a bore-hole designated as Seam I and interpreted geologically to be of Karharbari Formation. Palynologically it is characterized by the association of Indotriradites and Dentatispora. The other one is an outcrop seam, so far undetermined geologically. It contains preponderance of Callumispora, a spore genus that signifies Karharbari Formation. These coal seams, where so ever their lateral continuations extend, can be identified on the basis of the palynological contents qualitatively and to some extent also quantitatively.
The shortcomings and limitations of palynological methodology in the effort to achieve correlation of coal seams have been discussed and ways and means to mitigate the same suggested.
Gondwana Sequence of the northern Pranhita-Godavari Valley: its stratigraphy and vertebrate faunas
Authors: Kutty T.S. , Jain S.L. , Chowdhury T.R. 
Published: September 2022

The Gondwana Sequence in the northern part of the Pranhita-Godavari Valley consists of four formations of the Lower Gondwana and seven formations of the Upper Gondwana. The gross lithological characters and mappability are considered as the major criteria for delineating the formations. The name Kamthi Formation which has been used by different authors in different senses, is here used in the sense of Sengupta (1970). The rocks between the Barakar and this Kamthi are divided into four lithozones for limitations of mappability. Although some of these lithozones have earlier been designated as formations, at present not sufficient information is available to justify this. Only two breaks, both within the Upper Gondwana, are found to be present: there is no recognisable break between the Lower and the Upper Gondwana. A summary of this succession is presented in tabular form taking into account the words of earlier authors. The alternative views that are radically different from the one presented here are also discussed briefly. The usefulness of plant megafossils and fossil vertebrates in understanding the stratigraphy is discussed briefly and their role in determining the possible geological ages of some of the formations is mentioned.
The vertebrate fauna from a number of formations is listed. At least seven formations are fossiliferous as far as vertebrates are concerned. Of these, two belonging to the Triassic and one belonging to the Jurassic are quite well-documented. The other four are less well known, but serve as very useful time markers. All these vertebrate-bearing formations can be correlated with co-eval rocks elsewhere in the world. The difficulty of correlating continental deposits is realized and keeping this in view a tentative correlation is presented.
Jurassic and Lower Cretaceous dinoflagellate cysts from India with some remarks on the concept of Upper Gondwana
Authors: Garg Rahul , Khowaja-Ateequzzaman  , Jain K.P. 
Published: September 2022

A critical re-evaluation of the known records of dinoflagellate cyst assemblages from Jurassic and Lower Cretaceous sediments of India is made and stratigraphically significant taxa are identified and tabulated. Emphasis is laid on integration of dinocysts and ammonite evidence for stratigraphy precision. Significance of dinocysts in age determination of Kimmeridgian-Tithonian sequences of Kutch and Malla Johar is recognized. Berriasian dinocysts are not known from India. It is suggested that dinocysts assemblages documented from subsurface of East Coast of India are not older than Hauterivian as no conclusive evidence for Valanginian age, assigned by earlier workers, is available.
The traditional view regarding coastal marine Lower Cretaceous sequences as part of Gondwana is not tenable. It is suggested that the term Gondwana be reserved for inland, predominantly non-marine, fluviatile-lacustrine sediments as a lithostratigraphic unit. In view of the lack of any definite evidence of Jurassic sediments in intracratonic basins and the prominent post-Triassic hiatus, Late Triassic is considered to mark the upper age limit of Gondwana sequences.
Limits of Greater Indian Plate during Gondwana time
Authors: Acharyya S.K. 
Published: September 2022

Limits of the Greater Indian Gondwana continent varied with its break-up and collisional episodes. Late Palaeozoic basal Gondwana type glaciogene and associated sediments containing cold-water marine fauna, with or without Glossopteris, Cathaysian floral remains or admixtures occur in and across the Himalaya, in south Pamir, Tibet and in Shan-Tenesserim-Malaysian area, i.e., across the Late Mesozoic peri-Indian ophiolite belts. Cathaysian Flora with or without Glossopteris intercalations also occurs in western Iraq and New Guinea, both representing parts of the Gondwanic shield. Thus during Late Palaeozoic the Gondwana continents also hosted Cathaysian flora, especially in low palaeolatitudinal positions. The Himalaya, parts of Middle-East, Tibet, Shan-Tenesserim and Malaysian continental blocks therefore possibly formed parts of the Greater Indian Gondwanic continent.
The Late Cretaceous and Eocene olistostromal flysch belts tectonically flooring the ophiolite mélange of the Indus-Tsangpo and Naga-Chin Hills Andaman belts respectively delineate the northern and eastern continental margins of the Indian Plate. The present subduction zone beneath the Andaman island arc represents a westerly relayed Neogene margin of the Indian Plate.
Permian palynofossils from the eastern Himalaya and their genetic relationship
Authors: Srivastava S.C. , Anand-Prakash  , Singh Trilochan 
Published: September 2022

Palynofossils from the Permian sediments of the eastern Himalaya have been critically revised with reference to the marine invertebrate fossils contained at various levels. The Pebble Slate Member of the Rangit Formation having sporadic presence of Eurydesma (Biozone 1) has not yielded palynofossils but the younger Rilu Member has yielded a radial monosaccate rich assemblage (Biozone 2). The association of Leiosphaeridia in this assemblage in Barpathar area characteristically indicates marine influence. Biozone 3 characterised by Callumispora + Parasaccites association is present in marine Garu Formation in Siang and Subansiri, non-marine Bhareli Formation in Kameng and Lower Coal Measures in Darjeeling District. Scheuringipollenites rich Biozone 4 is characteristically associated with the marine invertebrates in Siang District (Garu Formation) only; elsewhere it occurs independently. Biozones 5 and 6 are characterized by the abundance of striate-disaccate pollen grains, the latter having Indospora, Thymospora and Crescentipollenites and represent Upper Barakar and Raniganj palynofloras, respectively.
The Permian sediments in eastern Himalaya are in lithological contrast with the intracratonic continental sediments of the Peninsula but their floristic resemblances are close. Biozones 1 and 2 are comparable to Talchir palynoflora which is related to glacio-marine model of sedimentation. During the deposition of sediments containing Biozone 3, comparable to Karharbari palynoflora, the marine environment seems to have existed continuously from Siang to eastern Kameng but westwards certain areas were under fresh water environment. Similarly, Biozone 4 is associated with marine fossils in Siang only but elsewhere it is typically associated with fluvial sediments. Thus an eastward regression of the sea is plausible during Karharbari and Lower Barakar times. During the younger palynofloras having Upper Barakar (Biozone 5) and Raniganj (Biozone 6) affinities the conditions of deposition appear to be exclusively fluvial in nature. It is clearly indicated that a larger segment of sedimentation in these marginal basins of eastern Himalayas has continued under marine environment while in peninsular India the intracratonic depositional basins were under fluvial environment during the same time span.
Morphographic study of Permian palynomorphs: Callumispora, Parasaccites, Crucisaccties and Faunipollenites
Authors: Tiwari R.S. , Srivastava S.C. , Tripathi Archana , Vijaya  
Published: September 2022

Taxonomy is the primary requisite for biostratigraphy, and objective resolution of organisations as well as finer morphography leads to effective circumscription of taxa for taxonomy. Obviously, such an approach is critical for dispersed microfossils where form and shape remain the only tools for classification.
The palaeopalynology has come to its age and the inevitable discrepancies which had crept in during its initial stage, have been now identified in delimitation of taxa. In this catalogue, an attempt has been made to review the generic and specific groups in four Permian palynotaxa, viz., Callumispora, Parasaccites, Crucisaccites and Faunipollenites. On this line of approach, more taxa will be taken up subsequently, with a view to streamline their taxonomic treatment. The ultimate aim is to evolve a simplar, logical and practical system of identification based on major qualitative expressions of spore-pollen construction and exine characters.
The relative abundance of these four genera through Lower Gondwana formations of India has also been determined and their index value discussed. As such, the distribution of species of these genera is not known from the earlier works. It is therefore hoped that future workers would deal with each genus up to the specific level for determination of their distribution which will prove very useful for finer correlation. Only the selected species of distinct identity and restricted range have real practical value in biostratigraphy.
Morphological trends in Gondwana plants
Authors: Bajpai Usha 
Published: September 2022

The term Gondwana has recently been redefined to include the group of terrestrial rocks in the Indian Craton, that was initiated with a basal Permian glacigene epoch and terminated with the large hiatus at the top of the Triassic. The Gondwana Supergroup as redefined now comprises Talchir, Damuda, Panchet and Mahadeva groups and ranges in age from the earliest Permian to latest Triassic or earliest Jurassic (Venkatachala & Maheshwari, 1991).
The vegetational scenario of Gondwana shows mixture of plants belonging to quite distinct habitats. The morphological adaptations of plants that thrived at all levels on land, in continental water, upland and in environments of exceeding dryness are significant. Leaf size varies from small to large with variety of apex and base, midribless to prominent midrib, non-petiolate to petiolate, veins loosely arranged, narrow mesh type of venation to open mesh and narrow mesh type. Leaf cuticle of glossopterids also shows variations.
Most of the Gondwana woods show variation in pith and primary xylem and secondary xylem. Pith varies from homo- to hetero-cellular. Primary xylem shows variation from endarch to mesarch. The secondary xylem is pycnoxylic, homoxylous. Secondary xylem shows well-marked growth rings. There is a great variation in the pitting of secondary tracheids. Xylem rays vary from uni- to multi-seriate. The ray field-pits also show diversity.
Wide diversities are also seen in the morphology of pteridophytic megaspores and of reproductive organs of gymnosperms. The exosporium of megaspore is either smooth or variously ornamented. The mesosporium is with or without cushions. Reproductive organs are known only for the glossopterid group and are of two types.
The changing patterns in leaves, woods, megaspores and reproductive organs of Gondwana plants may provide significant data for charting of morphotrends in these organs. It can probably also be established if these morphotrends were ecologically controlled temporary and transient phase or were genetically controlled leading to evolution of new types.
Changing pattern of vegetation in the intermontane basin of Kashmir since 4 Ma: a palynological approach
Authors: Gupta H.P. 
Published: September 2022

The Upper Karewas are devoid of biomass potential and hence no palynostratigraphy could be established. In contrast, Lower Karewas are both quantitatively and qualitatively rich in biota. The major areas of study include Dubjan, Hirpur, Krachipathra, Ningle Nullah, Laredura, Liddarmarg, Butapathri, Wapjan, etc. Dubjan, supposedly the basal part of the Karewa sequence, overlies unconformably the Panjal volcanics and Hirpur overlies the Dubjan. Recent palaeomagnetic studies suggest that these sediments span late Gilbert to middle Matuyama magnetic polarity ranging in age between 3.5 to 2.0 Ma. Wapjan is the uppermost pan of the Lower Karewa and falls between late Matuyama to early Bruhnes ranging in age between 0.75 to 0.70 Ma.
Palynological and palaeobotanical investigations carried over a large number of exposures have revealed that there is no unanimity in vegetation all through the Karewa deposits, instead, a variety of vegetation types has been recorded in time and space indicating their development under different circumstances. The vegetation met here varies from typical subtropical to desertic alpine type. The climate has not been static for a long period rather reciprocity in the climate has been recorded which has been deciphered from vegetal signatures left by the nature. Post-glacial sediments from the lake basin in the valley have also been investigated, which reveal three-fold vegetational development reflecting on three-fold climatic evolution.
Last 20,000 years of climatic change
Authors: Agarwal D.P. 
Published: September 2022

Recent evidence, especially from continental Asia, shows that there are marked latitudinal differences in global climatic changes. From India, we now have new evidence from Kashmir, Rajasthan and the Arabian Sea which shows that in the north (35°- 40° N latitude) warming had started c. 20,000 yrs BP in Kashmir, Ladakh and Nepal when in higher latitudes it was still the Last Glacial Maximum (LGM). At c. 18 Kyr, Butapathri (Kashmir) bogs show emergence of thermophilous plants like Alnus, Juglans, Carpinus at the cost of conifers. A palaeosol on the loess profile of Kashmir is datable to c. 18 Kyr which again shows climatic amelioration. Organic matter from this palaeosol gives δ 13C values of about -24‰ indicating that it was derived from C3 type of vegetation. Presence of an Upper Palaeolithic culture at this time, in Kashmir, again confirms a period of climatic amelioration.
From Ladakh, Bhattacharya has inferred climatic amelioration from the higher percentage of Juniper during 20- 20 Kyr period. Similarly in Nepal, a climatic amelioration is indicated. In Rajasthan, c. 18 Kyr is a period of aridity. Maximum sand building activity is TL dated by Singhvi to c. 14 Kyr and just preceeds the strengthening of the monsoon in c. 13 Kyr. Upwelling at c. 13 Kyr in the Arabian Sea has been reported by Anderson et at. (1990) and the French group has shown a similar evidence of monsoon strengthening at c. 13 Kyr based on pollen evidence fom African lakes. Unfortunately, we have only one 14C date from Butapathri which shows that at c. 10 Kyr the cooler oscillation was on its way out and warming had gradually started. We need more closely spaced 14C dates for such profiles. In the Arabian Sea cores the spike at c. 18 Kyr of freshwater (low salinity, low δ 18O, high δ 13C) has been interpreted variously as due to the strengthening of NE monsoon or due to Tibetan ice melt. The role of Tibet in climate forcing is being emphasized by multiple new data. It will be relevant to know what was happening in peninsular India during this period.
Himalayan coals: their nature, composition, formation and rank
Authors: Anand-Prakash  
Published: September 2022

The results of maceral, microlithotype and reflectance analyses, so far carried out on the Palaeozoic (Permian) and Tertiary coals of Himalaya, have been presented along with the details of geological and chemical (proximate) studies. The Permian coals, enclosed in the sediments dispersed as thrust slices in the eastern Himalaya, are characterized by their high rank and the dominance of the maceral vitrinite. In general, these coals are classified as semianthracite, except for the Bhutan coals which are of low rank and high volatile bituminous in nature. Almost all the macerals contain fairly high amount of mineral matter. Finely disseminated argillaceous matter is the most common mineral suite present in the coals followed by carbonates and iron sulphide (pyrite). In most of the cases, the mineral matter is present as infillings in numerous sets of fissures which traverses the coals. These infillings seem to have been developed during the tectonic activity and represent secondary minerals impregnated in various macerals. Often the presence of high amount of mineral matter has greatly reduced the quality of coal. Besides, the marine animal fossil-bearing mineral concretions (coal balls) have indicated that these coals were formed in a series of lagoons under the influence of marine conditions.
The Upper Tertiary coals, associated with the Tipam sediments in the eastern Himalaya, occur as small lenses, very thin impersistent seams and pockets which are characterized by the dominance of maceral vitrinite. It is generally represented by the structured variety (telinite). In general, the cellular structures indicate that these coals have been formed by the burial of wood logs in the fluvial sediments. An important feature of telinite is the presence of folded tissues which attain prominence in the coals occurring closer to the main boundary faults. The coals in this area exhibit lignite-bituminous stage in rank and are comparable to the Mesozoic coals in peninsular India. This stage in rank has been possible mainly due to the tectonic disturbances.
The Lower Tertiary coals of Jammu area are the only economically workable deposits in the Himalayas. These are associated with the beds containing marine animal remains. This indicates that coal formation took place under near-shore environment. These coals are comparable to the Permian coals of the eastern Himalayas. They are also rich in maceral vitrinite and semianthracitic in rank. Such a high rank of these Tertiary coals may be attributed to the effect of tectonic movements in the Himalayan areas.
The glossopterid group of plants in an evolutionary perspective
Authors: Maheshwari H.K , Srivastava A.K. 
Published: September 2022

The glossopterid group of plants was the most dominant constituent of the Permian vegetation of the Gondwana Supercontinent. During last one hundred and fifty odd years, a staggering amount of data has accrued on leaves, wood, root, fructifications, seed and pollen that possibly belonged to this group. Evolutionary pathways with the group, however, are yet little understood.
Considering the venation and epidermal features of the leaves, two patterns are unfolded; one with leaves having dichotomizing, almost parallel veins and stomata in linear rows, the other with dichotomising and anastomosing veins and stomata irregularly distributed in the mesh areas.
Oldest glossopterid fructifications, viz., Arberia/Dolianitia show a certain resemblance with the cordaitalean fructifications, thus suggesting that group of plants with Cordaites/Noeggerathiopsis/Pantophyllum type leaf and Arberia/Dolianitia type infructescence probably was the precursor of the glossopterids. Overall evidence suggests the development of this group of plants along two successive lineages.