Bijai Prasad

Ordovician–Silurian acritarch biostratigraphy of the Tethyan Garhwal Himalaya, India

Abstract The Ordovician–Silurian succession of the Shiala and Yong Limestone formations, Tethyan Garhwal Himalaya (Uttar Pradesh), reveals a rich assemblage of acritarchs. The assemblage includes sphaeromorphs, acanthomorphs, netromorphs, polygonomorphs, diacromorphs and herkomorphs. Seventy species belonging to thirty-seven acritarch genera have been identified. The new forms are described. Four distinct local acritarch assemblage zones are proposed. They are: (IV) Leiofusa algerensis–Multiplicisphaeridium osgoodence; (III) Tetradinium minutum–Dactylofusa sp. cf. D. oblancae; (II) Domasia trispinosa–Deunffia monospinosa; (I) Baltisphaeridium longispinosum var. longispinosum–Multiplicisphaeridium ornatum. The palynological assemblages identified in the Garhwal Himalaya correlate with Ordovician–Silurian assemblages of the United Kingdom, Belgium, Russia, North Africa, Saudi Arabia and China, etc. The presence of biostratigraphic index forms suggest a Late Ordovician to Middle Silurian age for the Shiala Formation and a Middle to Late Silurian age for the Yong Limestone. Thus, the Ordovician–Silurian boundary lies within the Shiala Formation and negates an earlier view that this boundary lies at the base of the Yong Limestone Formation. In the systematic part, five new species of acritarchs, Neoveryhachium distinctum Sinha, Prasad and Srivastava, sp. nov., Tetradinium minutum Sinha, Prasad and Srivastava, sp. nov., Triangulina densus Sinha, Prasad and Srivastava, sp. nov., Geron indicus Sinha, Prasad and Srivastava, sp. nov., and Leiofusa shialensis Sinha, Prasad and Srivastava, sp. nov., are described and illustrated.

Gondwana biostratigraphy of the Purnea Basin (eastern Bihar, India), and its correlation with Rajmahal and Bengal Gondwana basins

Integrated biostratigraphic studies are undertaken on the newly discovered Gondwana successions of Purnea Basin which have been recognized in the subsurface below the Neogene Siwalik sediments. The four exploratory wells, so far drilled in Purnea Basin, indicated the presence of thick Gondwana sussession (± 2450m) with varied lithological features. However, precise age of different Gondwanic lithounits of this basin and their correlation with standard Gondwana lithounits is poorly understood due to inadequate biostratigraphic data.Present biostratigraphic studies on the Gondwana successions in the exploratory wells of PRN-A, RSG-A, LHL-A and KRD-A enable recognition of fifteen Gondwanic palynological zones ranging in age from Early Permian (Asselian-Sakmarian) to Late Triassic (Carnian-Norian). Precise age for the Gondwanic palynological zones, recognized in the Purnea Basin and already established in other Indian Gondwana basins, are provided in the milieu of additional palynological data obtained from the Gondwana successions of this basin.The Lower Gondwana (Permian) palynofloras of Purnea Basin recorded from the Karandighi, Salmari, Katihar and Dinajpur formations resemble the palynological assemblages earlier recorded from the Talchir, Karharbari, Barakar and Raniganj formations respectively, and suggests the full development of lower Gondwana succession in this basin. The Upper Gondwana (Triassic) succession of this basin is marked by the Early and Middle to Late Triassic palynofloras that resemble Panchet and Supra-Panchet (Dubrajpur/Maleri Formation) palynological assemblages, and indicates the occurrence of complete Upper Gondwana succession also in the Purnea Basin.The lithological and biostratigraphic attributes of Gondwana sediments from Purnea, Rajmahal and western parts of Bengal Basin (Galsi Basin) are almost similar and provides strong evidences about the existence of a distinct N-S trending Gondwana Graben, referred as the Purnea-Rajmahal-Galsi Gondwana Graben. Newly acquired biostratigraphic data from the Gondwana sediments of CHK-A, MNG-A and PLS-A wells from central part of Bengal Basin and Bouguer anomaly data suggest that these wells fall in a separate NE-SW trending graben of “Chandkuri-Palasi-Bogra Gondwana Graben”. Although, the post-Gondwana latest Jurassic-Early Cretaceous Rajmahal Traps and and intertrappean beds succeed the Upper Gondwana successions in Rajmahal, Galsi and Chandkuri-Palasi Gondwana basins, but not recorded in the drilled wells of Purnea Basin, instead succeeded by the Neogene Siwalik sediments.

Applications to Soft Matter: general discussion

Vinothan N. Manoharan, Guruswamy Kumaraswamy, Madivala G. Basavaraj, Sanat Kumar, Siddharth Kulkarni, Ranjini Bandyopadhyay, Sudeep Punnathanam, Ajeet Srivastav, Lola Gonzalez-Garcia, G V Pavan Kumar, Daan Frenkel, Radhika Poojari, Priyadarshi Roy Chowdhury, Gourav Shrivastav, Mukta Tripathy, Vimala Sridurai, Alison Edwards, Madhura Som, B. L. V Prasad, Lynn Walker, Neena S. John, Yon Ju-Nam, Yogesh M. Joshi, Nirmalya Bachhar, Charusita Chakravarty, Rajdip Bandyopadhyaya, Zakiya Shireen, Nicholas Kotov, Oleg Gang, Alamgir Karim, Mario Tagliazucchi, Erika Eiser and Andrea Tao

Synthesis of Nanoparticle Assemblies: general discussion

Madhura Som, Sristi Majumdar, Nirmalya Bachhar, Guruswamy Kumaraswamy, G. V. Pavan Kumar, Vinothan N. Manoharan, Sanat Kumar, Madivala G. Basavaraj, Siddharth Kulkarni, Ranjini Bandyopadhyay, Sudeep Punnathanam, Himani Medhi, Ajeet Srivastav, Daan Frenkel, Mukta Tripathy, Erika Eiser, Lola Gonzalez-Garcia, Priyadarshi Roy Chowdhury, Jayant Singh, Vimala Sridurai, Alison Edwards, B. L. V. Prasad, Amit Kumar Singh, Michael Bockstaller, Neena S. John, Jyoti Seth, Mayank Misra, Charusita Chakravarty, Vandana Shinde, Rajdip Bandyopadhyaya, Jacques Jestin, Radhika Poojari, Nicholas Kotov, Oleg Gang, Alamgir Karim, Yon Ju-Nam, Steve Granick, Semen Chervinskii and Andrea Tao

Pachwarophyllum santhalensis gen. et sp. nov. from the lower Gondwana of Bihar, India

Pachwarophyllum santhalensis gen. et sp. nov. is described from coal bearing beds of the Barakar Formation in the Pachwara Coalfield, Rajmahal Hills, India. The new genus is characterised by flabellate non-petiolate leaves with an obcordate apex and repeatedly forked non-anastomosing veins.