Journal of the Palaeontological Society of India最新文献

{"title":"A first account of pteropod taxa from off Saurashtra, western offshore of India: Implications for palaeohydrological studies","authors":"Mugdha Ambokar, R. Panchang, Pawan Govil, Syed Azharuddin","doi":"10.1177/05529360231219623","DOIUrl":"https://doi.org/10.1177/05529360231219623","url":null,"abstract":"Pteropod aragonitic shells contribute to 12% of biogenic inorganic carbon flux to the world ocean but are also prone to dissolution. Though their state of preservation and generic ratios, namely Creseis/Limacina have been used as a proxy for palaeoclimatic reconstruction, their taxonomic attributes have remained unexplored. The present study reports 20 pteropod species from a single location in the northeastern Arabian Sea offshore of Saurashtra, all of which show the same degree of preservation throughout the core. The occurrence of mesopelagic fauna in the study area located on the shelf region however points to palaeoenvironmental changes and underscores the importance of employing pteropod assemblages for palaeoclimatic reconstructions in the study area.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139173723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palynostratigraphy and depositional environment of Tura and Pre-Tura sedimentary successions in Dhansiri Valley of Upper Assam Shelf, Assam & Assam-Arakan Basin, Assam, India","authors":"Kanchi Narsimha, Lusuchu Phor, Tushar Kanti Ghosh, Sudeshna Panda, Divya Geddada, Biswa Prakash Patra","doi":"10.1177/05529360231216337","DOIUrl":"https://doi.org/10.1177/05529360231216337","url":null,"abstract":"Detailed palynological investigations have been carried out to reconstruct stratigraphy and interpretation of depositional environment of Tura and Pre-Tura sedimentary sections in Dhansiri Valley of Upper Assam Shelf, Assam & Assam-Arakan Basin. Sediments of the Tura Formation dated as Early Eocene and interpreted to be deposited under subtidal to inner shelf environment. Pre-Tura sediments, developed in studied wells, led to the identification of Dergaon, Bamangaon and Moabund formations with intervening unconformities, having different tectonic history and distinct palynofossil assemblages. Early Permian sediments of the Dergaon Formation (=Talchir Formation), the oldest in the basin are deposited under the intracratonic phase, overlie the metamorphic basement complex. The sediments of the Dergaon Formation are unconformably overlain by the Bamangaon Formation deposited during the Early Cretaceous, whereas, in well DR-A, the sediments of the Dergaon Formation are directly overlain by the Moabund Formation corresponding to the Late Maastrichtian age. The sediments of the Tura Formation overlie the Maobund Formation in well DR-A, and they overlie the Bamangaon Formation in the rest of the wells in Dhansiri Valley.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138584318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facies and trace fossils of the Upper Cretaceous Sillakudi Formation (Cauvery Basin, S. India) and their palaeoenvironmental significance","authors":"Amruta R. Paranjape, Kantimati G. Kulkarni, Anand S. Kale","doi":"10.1177/05529360231205315","DOIUrl":"https://doi.org/10.1177/05529360231205315","url":null,"abstract":"The Sillakudi Formation is a sandstone-dominated succession bounded by unconformities. It represents the oldest unit of the Ariyalur Group deposited during the Campanian under fully established passive margin depositional conditions. The present study is an attempt to interpret the depositional palaeoenvironment of Sillakudi Formation based on its trace fossil content, supported by sedimentological evidences. Detailed sedimentological and ichnological observations were undertaken in multiple traverses and spot locations across the Sillakudi Formation. The Sillakudi Formation is subdivided into four facies associations, each represented by a distinct ichnology and environment of deposition. Unit 1 comprises conglomerates grading upwards into pebbly sandstones almost devoid of trace fossils except a few Planolites isp. indicating a high-energy foreshore-to-shoreface environment. Unit 2 consists of glauconitic sandstones with Ophiomorpha nodosa, O. annulata, Thalassinoides isp. and Skolithos linearis, belonging to the Skolithos ichnofacies indicating deposition in shoreface to offshore transition environments. Unit 3 comprises pebbly to very coarse-grained massive sandstones, characterised by an almost monospecific Skolithos ichnofacies indicating rapid colonisation of beds in a delta-front associated debris flows and calcareous sandstones alternating with claystones containing a diverse Cruziana ichnofacies with an ichnoassemblage comprising of Trichichnus isp., Scolicia prisca var. laminites, S. ?prisca, S. vertebralis, Palaeophycus tubularis, Planolites beverleyensis, P. montanus, Taenidium isp., Thalassinoides suevicus, Ophiomorpha isp., Chondrites isp. and Phycodes isp., pointing towards deposition in calmer, possibly dysoxic outer shelf prodeltaic environments. Unit 4 has pebbly to gritty cross-bedded sandstones exhibiting the development of networks of Thalassinoides isp. and Ophiomorpha isp., indicating shallow sub-tidal to intertidal conditions of deposition. The overall succession is interpreted to show initial deepening followed by shallowing.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134954274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diatoms and Water Quality Indices in Thamirabarani River help Environmental Impact Assessment of stretch between Naranammalpuram and Punnakayal, Tamil Nadu, India","authors":"A. Rajeshkanna, R. Venkatachalapathy","doi":"10.1177/05529360231209623","DOIUrl":"https://doi.org/10.1177/05529360231209623","url":null,"abstract":"The present study reports the occurrence of diatom taxa, their distribution and ecology in Thamirabarani River between the study areas Naranammalpuram and Punnakayal, covering the districts of Tirunelveli and Thoothukudiin Tamil Nadu, India. The study employs diatoms collected from 10 different locations in the Thamirabarani River to monitor its quality. A total of 40 diatom taxa belonging to 20 genera were recorded in the study area. The dominant presence of diatom taxa, such as Aulacoseira ambigua, Cocconeis placentula, Cyclotella meneghiniana, Cymbella tropica, Discostella stelligera, Gyrosigma acuminatum, Navicula cryptonella, Nitzschia amphibia, Planothidium lanceolatum, Staurosirella pinnata, and the water quality index values (29–48) recorded at sites 1 to 7 indicate oligotrophic due to good flow of water. The abundant of diatom taxa, such as Diadesmis confervacea, Gomphonema parvulum, Nitzschia palea and Pinnularia gibba, were recorded at sites 8–10, and the water quality indices (100–110) indicate eutrophication attributable to less flow of water, high dispersion of cremation ashes (the casting ceremony) and anthropogenic activities. Particularly, locations around Punnakayal are most polluted due to the dumping of fish wastes as well as stagnant water.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134901875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrographic analysis of Oligocene carbonates of Kachchh basin","authors":"Shweta Patil, Ashwin Pundalik, Eshan Pansare","doi":"10.1177/05529360231208812","DOIUrl":"https://doi.org/10.1177/05529360231208812","url":null,"abstract":"The Kachchh basin is located on the northwestern margin of India. The basin consists of a relatively continuous sequence of sediments from the Mesozoic, followed by the Deccan Traps and finally a complete sequence of the Cenozoic sediments. The Cenozoic sediments of Kachchh basin are mainly shallow marine deposits characterised by five formations viz. Matanomadh, Naredi, Harudi, Fulra Limestone and Maniyara Fort Formation. The Maniyara Fort Formation belongs to the Oligocene age. The field and petrographic characteristics of the Oligocene limestones from the Golay river section were studied in order to understand the depositional environment. The petrographic investigation of the carbonate rocks of three members of the Maniyara Fort Formation, namely Lumpy Clay Member, Coral Limestone Member and Bermoti Member provides important information for understanding the depositional facies and diagenetic signatures. The Lumpy Clay Member has shale-siltstones with interbedded limestones, characteristically composed of a significant proportion of detrital grains of quartz and some lithic fragments. The lithic fragments are sub-angular to rounded, which indicates substantial transport. They are also worn down and broken, bear small cracks which are filled by micritic matrix or mud. The presence of stylolitic seams within the limestone (though not significant) along with mud filling is also noticed. The dissolution is not prominent, pointing towards shallow burial of the sediments. Paucity of marine fossils as well as the rarity of foraminifera in the Lumpy Clay Member indicate a restricted to semi-restricted shallow marine environment. The limestones of the Coral Limestone Member are petrographically classified as packstone, wackestone and mudstone. Thus, the environment of deposition seems to have varied from restricted lagoonal to shallow marine environment. The Bermoti Member is characterised by a lens of claystone, which consists of both greyish to yellow coloured claystones interbedded with limestones. The Bermoti limestones are petrographically classified as packstone, wackestone and mudstone assemblage. The limestones were observed to be highly micritised, which indicates open, shallow marine settings. The Maniyara Fort Formation, thus characterised by wackestone-packstone-mudstone facies of carbonates, is interpreted to be part of a carbonate ramp system. The limestones from Maniyara Fort Formation exhibit signatures of marine as well as meteoric diagenesis.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135241647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First report of Eocene echinoids from the Sylhet Limestone, Mikir Hills of Assam, India: palaeontological, palaeogeography and palaeoenvironmental significance","authors":"Kapesa Lokho, JosÉ Francisco Carrasco, Shantajhara Biswal, Kezhakielie Whiso, Ansuya Bhandari","doi":"10.1177/05529360231205313","DOIUrl":"https://doi.org/10.1177/05529360231205313","url":null,"abstract":"This article reports two echinoid taxa viz. Ilarionia sindensis Duncan and Sladen (1884) and Porocidaris schmidelii Münster in Goldfus (1830) from the middle Eocene Sylhet Limestone of Mikir Hills, Assam. P. schmidelii is found from the Lutetian (middle Eocene) to the Priabonian (upper Eocene) in the following regions: NE of Spain, Biarritz (Southwestern France), Angoumé (Southern Aquitaine, France), Carinthia (Southern Austria), Venetian region of Italy Provence, Southern Alps of French, Istria (Croatia), Persian Gulf, Oman and Egypt. I. sindensis was first reported from the Eocene of Sindh province from the Khirthar Series (Pakistan) and Madagascar. It is also recorded from the Bartonian–Priabonian in the following regions: NE Spain, Biarritz in Southwestern France, Angoumé in Southern Aquitaine-France, Carinthia in Southern Austria, Italian region of Veneto, Provence and southern French Alps, Persian Gulf, Oman, Egypt and Istria. They are systematically described to know their stratigraphic, palaeoenvironment and palaeogeographic distribution. The material studied herein represents the first report from the middle Eocene of India, and it significantly expands the geographical extension of Eocene marine echinoids in the northeastern part of India.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135724898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent pollen spectra from Shimla water catchment sanctuary, Kufri (HP): Implications to interpret Holocene pollen records","authors":"Anjali Trivedi, P. Morthekai, Alka Shukla, Anupam Nag, Dhruv Sen Singh","doi":"10.1177/05529360231205149","DOIUrl":"https://doi.org/10.1177/05529360231205149","url":null,"abstract":"A better understanding on the connection between pollen assemblages and the vegetation that produced them is crucial to reconstruct past habitats and vegetation. Hence, it is necessary to comprehend the level of representation of plants in the modern pollen rain in a given study area. To ascertain the composition of pollen deposited on the surface sediments, palynological analysis of 19 surface soil (SS) samples and moss cushions (MSs) taken from various sites on the surface of the Shimla Water Catchment Wildlife Sanctuary (SWCWS), Kufri, Himachal Pradesh (India) was used in the current study. The dominance of arboreal pollen (trees and shrubs) over the non-arboreal pollen (herbs) was observed. Among the trees, conifers such as Cedrus deodara, Pinus wallichiana, Picea smithiana and Abies pindrow were found in MSs as well as in SS samples. The representation of these taxa corresponds with their factual presence in the forest floristics in the region. The moist and shady habitats loving broad-leaved tree elements such as Quercus and Rhododendron were also found in good numbers. Two multivariate statistical methods, cluster analysis and principal components analysis, were used to study the associations of studies pollen taxa and the variability among them. All the 19 samples were clustered into four. This analysis will help to interpret the palaeodata whether the landscape was influenced by anthropogenic activities or not in the recent past.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134906254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery of <i>Parapelomys</i> (Murinae) from the Siwalik Group of Mohand, NW Himalaya: Palaeobiogeography implications","authors":"Ansuya Bhandari, Lawrence J. Flynn, Kapesa Lokho","doi":"10.1177/05529360231205119","DOIUrl":"https://doi.org/10.1177/05529360231205119","url":null,"abstract":"An isolated rodent lower molar is being reported from Mohand II locality (gastropod/otolith locality) of the Siwalik Group exposed in the Mohand area, along the Saharanpur–Dehradun road. The fossils yielding mudstone units from the Siwalik Group exposed in the Doon Valley, Mohand, in the western Himalayan region. The occurrence of this murine mouse lineage, Parapelomys, is consistent with the late Miocene age based on palaeomagnetic reversal stratigraphy. The fossil represents a species apparently more primitive and older than the type species of the genus Parapelomys robertsi. The find documents the geographic range of this mouse lineage 500 km southeast of the type area for the species in the Potwar Plateau, Pakistan. The associated fauna comprises gastropods, ostracods, cyprinid fish and crocodiles in our collection.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134905538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palynological response deduced through spatially distinct surface samples to reconstruct palaeoecology and palaeoclimate of the Barak Valley, Assam (Indo-Burma region), northeast India","authors":"Swati Tripathi, Arya Pandey","doi":"10.1177/05529360231205316","DOIUrl":"https://doi.org/10.1177/05529360231205316","url":null,"abstract":"Establishing modern pollen analogues under various vegetation types in a location is necessary without which it is difficult to accurately interpret fossil pollen assemblages in any region in terms of the past environment and palaeoclimate. We have analysed the modern pollen dataset of 30 surface soil and sediment samples from the forested, cropland, wetland and river sites of the Karimganj District in south Assam, to comprehend the connection between the recent pollen assemblage and the vegetation patterns in the Barak Valley. The overall pollen data reflect the tropical moist deciduous and semi-evergreen forest comprising Syzygium, Schleichera, Terminalia, Lagerstroemia, Duabanga, Sapotaceae, Ilex, Mesua and Schima under a warm and humid climate in response to rainfall variations in the region. The presence of Euphorbiaceae and Convolvulaceae inferred high monsoonal activity in and around the region. A robust relationship between local herbaceous vegetation and pollen was observed. The steady occurrence of cereal pollen (average 18.67%) along with other cultural pollen taxa like Brassicaceae, Coriandrum and Solanaceae illustrate intense agricultural activity around the valley areas. Multivariate principal component analysis (PCA) and box plot were applied to the quantified data obtained from pollen frequency analyses of the surface samples which clearly revealed a significant variation and similarity in vegetation types. Thus, an attempt has been commenced to precisely observe the behavioural pattern of modern pollen deposition in a varied depositional setting, which could, in turn, help in assessing the expanse of agricultural practices and the depth of deterioration of pristine forests and surrounding areas. This modern training dataset could also help in the precise reconstruction of past climate and vegetation shifts in the Barak Valley region. A correlation of regional palynodata with other regions of the Indian subcontinent and Indo-Burma will also be assessed for better interpretation.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134907655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microfacies correlation, analysis and palaeoecological reconstruction of Rupelian–Aquitanian succession in the central part of Lorestan Province, Northwestern Iran","authors":"Mohammad Rajabi, Saeedeh Senemari, Maryamnaz Bahrammanesh Tehrani","doi":"10.1177/05529360231181862","DOIUrl":"https://doi.org/10.1177/05529360231181862","url":null,"abstract":"The Oligocene–Miocene Asmari Formation is a sequence of shallow-water carbonate carbonates in the Zagros Basin. This formation is a significant oil reservoir that was formed in the Zagros foreland basin in southwestern Iran. The Razan section, located in the northwest of Zagros in the Lorestan province, was investigated to study microfacies types and evaluate the sedimentary environment. This section was then compared with the MakhmalKuh and Dehloran sections. It comprises limestone units with thin to medium strata, sometimes thick-bedded limestone, and other skeletal and non-skeletal components. Based on the biostratigraphy studies, 24 foraminifer genera and species have been identified. Among the foraminifera, the species of Peneroplis farsensis, Peneroplis evolutus, Austrotrilina howchini, Austrotrilina asmarensis, Dendritinarangi, Quinqueloculina sp., Triloculina trigonula, Pyrgo sp., Polymorphinids, Spiroluculina sp. and Meandropsina anahensis are the most important specimens. Based on identified co-occurrence taxa, the Austrotrilina howchini–Peneroplis evolutus assemblage zone has been recognised in the study area, which indicates early Miocene (Aquitanian). Texture analysis and faunal assemblages led to the recognition of fourteen microfacies. Based on the petrographic analysis, five depositional settings were determined in the studied section: (a) the outer ramp settings dominated by pelagic foraminifera, bryozoan, echinoid and benthic foraminifera such as Nummulites, Rotalia, Dendritina and Meandropesina iranica as a proxy for relatively deep marine conditions; (b) the mid ramp, characterised by sizeable perforate foraminifera such as Amphistegina, Operculina, Heterostegina and planktonic foraminifera; (c) the barrier, marginal marine environment dominated by foraminifera such as Miogypsinoides sp., Peneroplis, Meandropsina, Dendritina and Neoalveolina, as well as peloid and corallinacean algae; (d) the lagoon dominated by benthic foraminifera Austrotrillina, Dendritina, Peneroplis, Miogypsinoides, Borelis, Archaias, miliolids and red algae and (e) the tidal flat, the shallowest part of the inner ramp, dominated by fenestral dolo-mudstone without any fossils. The faunal assemblages represent warm tropical waters under euphotic and mesophotic conditions in a homoclinal ramp.","PeriodicalId":48900,"journal":{"name":"Journal of the Palaeontological Society of India","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135959724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}