Arindam Chakraborty

University of Malaya | UM · Department of Geology

Neogene radiolaria from late Miocene sediments of Andaman and Nicobar Islands

Tidal variations of phytoplankton were studied at two stations i.e., Station - 1 (Science Centre) and Station - 2 (Junglighat Bay) during the period of December 2010 to February 2011 in the coastal waters of South Andaman Islands, India. Phytoplankton biomass (Chlorophyll-a) was observed low (avg. 0.02- 0.1 mg m-3) in the stations during the sampli...

The present study deals with the diversity of phytoplankton from two selected stations, (Station 1: Junglighat and Station 2: Science Centre) during December 2010 to February 2011 in the coastal waters of Port Blair, South Andaman. Special emphasis was given to visualise the phytoplankton assemblages of the selected stations during low tide and hig...

The 25th Indian colloquium on micropa-laeontology and stratigraphy was organized recently. The principal themes of the silver jubilee event were: recent developments in micropalaeontology; advances in micropalaeontological studies of Foraminifera, Radiolarians, Ostracods, Bryozoa, Calcareous Algae, Diatoms, Nannoplanktons, Dinoflagellates, paly-nol...

Mangroves are distinguished as a unique ecotone, characterized by their specialized habitat and extreme environmental conditions , including high salinity, tidal fluctuations, elevated temperatures, low oxygen levels, and waterlogging. While these stressors impose numerous challenges on mangroves, the plants have evolved adaptive mechanisms to cope...

Microphytes incorporate several characteristics that are becoming increasingly important in a complex farming setting and the process of land reclamation. Microalgae/microphytes boost soil productivity and structure by adding minerals and improving microbial soil quality metrics and nutrient cycling. Protecting plants from disease, producing phytoh...

Amongst the various Neogene sequences in India, Andaman-Nicobar Basin in the northern Indian Ocean is one of the most important basins in this part of the world that represents the marine deep-water facies with a few shallow-water sequences. The Neogene sediments of the basin archives abundant siliceous microfossils namely radiolarians, diatoms, si...

Non-geniculate rhodolith-forming coral red algae have been recorded in the Long Formation, exposed in four different outcrops on Little Andaman Island (Hut Bay). Non-geniculate corallines are represented by species of Sporolithon Heydrich, 1897, Mesophyllum Lemoine, 1928, Lithothamnion Heydrich, 1897, Phymatolithon Foslie, 1898, Lithoporella (Fosli...

A detailed study on radiolarian biostratigraphy and paleoecology has been carried out from three outcrops on Havelock Island, belonging to the Ritchie's Archipelago of Andaman and Nicobar Group of islands. Though most of the radiolarian taxa are moderately preserved, it was possible to demarcate an age ranging from late early to early middle Miocen...

The oldest Asian record of alpheid shrimps (assigned to genus Alpheus) based on snapping claw fingertips from the Miocene (Aquitanian) Khari Nadi Formation (Kutch Basin, western India) reported herein extends the fossil record of Alpheidae from Asia by ~22 million years. An early Miocene (Aquitanian) age is estimated, based on the associated assemb...

Relatively large specimens (6–12 μm long) of the nannolith Nicklithus amplificus are characteristic of the late Miocene, having evolved in NN11 from the typical Miocene species Orthorhabdus rugosus. The present study was performed in order to identify the earliest occurrence, and to examine the evolutionary lineage, palaeogeography and palaeoclimat...

The present study has been carried out from the NGHP sediment core (NGHP-01-17A) of northeast Indian Ocean on different siliceous microfossils represented by diatoms and radiolarians along with calcareous nannofossils. Samples from the bottommost subunit Ic of the sediment core (684.09 mbsf to 369.62 mbsf) have been analysed. This contribution is t...

Primary productivity is an important component of the ocean. Primary productivity data from Pliocene of northern Indian Ocean is lacking. Marine siliceous organisms viz., diatoms, radiolarians, silicoflagellates and siliceous sponges uptake dissolved silica (dSi) from the seawater. The biological uptake of dissolved silica (dSi) from the seawater a...

Thirty-two planktonic foraminiferal taxa have been identified based on Bright Field microscopic study as well as Scanning Electron Microscopy on the samples collected from the outcrop adjacent to the type section of Neill West Coast Formation at Neil Island of Ritchie's Archipelago, northern Indian Ocean. The planktonic foraminiferal taxa belong to...

Neogene sediments of the Andaman and Nicobar Islands in northern Indian Ocean, specifically the lower Miocene (Burdigalian) to lower Pliocene (Zanclean) sequences, were analysed for calcareous nannofossils that yielded well-preserved and diverse assemblages. The majority of samples contained stratigraphic marker taxa that allowed us to identify suc...

The present contribution provides a study of calcareous nannofossils and siliceous microfossils from the Sawai Bay Formation on Car Nicobar Island, northern Indian Ocean. Two stratigraphically short sediment intervals near Sawai Bay have been examined. Qualitative and quantitative microfossil analyses show the Sawai Bay ‘A’ Section to be devoid of...

In the Ritchie’s Archipelago of the Andaman group of islands (Northern Indian Ocean), Havelock Island is the largest one. The present study on diatoms has been carried out on three outcrops of Havelock Island situated in Kalapathar, South Point and Laccam Point localities. Samples collected from the three Neogene outcrops yielded poor to moderately...

Global warming is the predominant cause for several changes in the present world. This warming is caused mainly by the accumulation of greenhouse and other harmful gases in the atmosphere. In this scenario, crop production has seen a major challenge. Some of the agricultural problems are caused due to the rise in human population, climate change, u...

In the present study from the late Pliocene of Neill West Coast Formation, Neil Island, serpulid tubes assignable to Ditrupa gracillima Grube have been identified with the help of tube morphological (light microscopy) and ultrastructural (SEM) studies. This is the first record of the species from the late Pliocene of India. The outer layer of D. gr...

Microfossil assemblages and lithological variations of the marine Cretaceous-Palaeocene (Danian) self succession of the Cauvery Basin, southern India has been a matter of attraction for the geoscientists and palaeontologists since the mid-nineteenth century. As a matter of fact, it has provided world class data on the invertebrates from the mid Cre...

Meeting Report: 12th International Symposium on Fossil Algae, Lucknow, India - September 16-18, 2019

Field Guide book to Andaman and Nicobar Islands

Abstract volume of 12th International Symposium on Fossil Algae

Comparative morphology and systematics has been an essential tool for research in biological science and evolutionary biology, but with rapid integration of molecular techniques into systematics and phylogenetics, the role of morphological attributes in evolutionary biology and taxonomy has become debatable. Scientists have gradually become more in...

This paper provides an overview of stable isotope analysis (H, C, N, O, Si) of the macro-and microscopic remains from aquatic organisms found in lake sediment records and their application in (palaeo)envi-ronmental science. Aquatic organisms, including diatoms, macrophytes, invertebrates, and fish, can produce sufficiently robust remains that prese...

In the Havelock Island of the Ritchie’s Archipelago (northeastern Indian Ocean), two lithological successions viz., the Inglis and Long formations, are exposed. Chronostratigraphically, the Havelockian Regional Stage has been named on this island for the sediments of both the formations. Based on previous planktonic foraminiferal biostratigraphy, t...

The occurrence of a diverse range of conifers and bennettitales is characteristic of the macroflora from the Early Cretaceous of the Rajmahal Basin, India. In the present paper two new conifer taxa assigned to the families Cupressaceae and Podocarpaceae are described from the intertrappean sediments of the Rajmahal Formation in Jharkhand State. The...

Taxonomic analysis of fresh water phytoplankton based on bright field microscopy and SEM studies is yet to be done in depth that may elucidate a number of new taxa. The present study on the assemblage of fresh water phytoplankton is focused to interpret the ecological condition of the studied water body of Bankura District in West Bengal. Phytoplan...

The present paper deals with the occurrence of a Halimeda bioherm facies represented by five different forms of the genus. The halimedaceans have been identified by thin section analysis of limestones from the middle Miocene (Serravallian) of the Butler Bay Section, Little Andaman Island (Hut Bay), India. All these forms are reported herein for the...

The Ph.D. thesis work hovers on a first comprehensive study on the diversity and palaeoecology of various benthic and planktonic, siliceous and calcified microfossils from the Neogene outcrops at different islands of Andaman and Nicobar Group. Amongst the two islands of Ritchie’s Archipelago the three outcrops of Havelock Island yielded moderately...

Petrographic thin section analysis of the samples collected from the type section of Neil West Coast Formation, situated in the west coast of Neil Island yielded moderately preserved coralline red algae, benthic and planktic foraminifers, coral fragments, echinoid spines and gastropod shells. The coralline red algae are represented by both non-geni...

The late Miocene (Tortonian) diatoms in 21 outcrop samples from Neil Island, Andaman and Nicobar Islands were investigated with eighty two planktonic and benthic taxa belonging to 35 genera. Principal Component Analysis reveals the existence of two distinct groups; samples dominated by Thalassionema nitzschioides and Thalassiothrix longissima, belo...

Lithological variations and fossil assemblages of the marine Cretaceous–Palaeocene (Danian) self succession of the Cauvery Basin, southern India has been a matter of attraction for the geoscientists and palaeontologists since the mid-nineteenth century. As a matter of fact, it has provided world class data on the invertebrates from the mid Cretaceo...

Miocene diatoms from the Havelock Island of Ritchie’s Archipelago Group, South Andaman with interpretation on Palaeoenvironment Arindam Chakraborty, Abhijit Mazumder & Amit K. Ghosh Birbal Sahni Institute of Palaeobotany, 53 University Road Lucknow-226 007, Uttar Pradesh, INDIA E-mail: flywidari@gmail.com, abhijit.mazumder.email@gmail.com, akghos...

TIDAL VARIATION OF PHYTOPLANKTONS IN SOUTH ANDAMAN AND ITS IMPLICATIONS ON THE FUTURE CLIMATE CHANGE Arindam Chakraborty1,2, Gadi Padmavati2, Amit K Ghosh1 Email: flywidari@gmail.com 1. Birbal Sahni Institute of Palaeobotany, Lucknow-226007, Uttar Pradesh, India. 2. Department of Ocean studies and Marine Biology, Pondicherry University, Brooksha...

Meiofaunal community composition from Rushikulya Coastal region: An Ecologically Important Ground for Olive Ridley Turtles Meiofauna are used as models in assessing the impacts of changes (natural or anthropogenic) in an aquatic ecosystem. A major but unprotected ecosystem of Olive Ridley (Lepidochelys olivacea) turtle’s nesting site in Rushik...