Abstract In the Bay of Bengal, the Andaman and Nicobar Islands represent part of the Burma-Sunda-Java subduction complex. The Islands are composed of sediments ranging in age from Jurassic to Recent, represented by ophiolites, flysch sediments, along with deep marine sediments scraped off from the subducting plate. The stratigraphic succession that overlies meta-sedimentary and ophiolite suites consists of turbidite and non-turbidite sequences, along with thick-bedded nannofossil chalks. The present study describes ichnofabrics of chalks from the Inglis Formation (Early to Middle Miocene). These chalks are highly to moderately bioturbated and comprise several levels of ferruginised layers as weak discontinuity surfaces. The studied section shows the recurring occurrence of ichnotaxa belonging to Asterosoma, Chondrites, Cladichnus, Ophiomorpha, Palaeophycus, Planolites, Taenidium, Thalassinoides, and Zoophycus. Sediments are represented by Bioturbation indices varying between BI-2 to BI-5, represented by (a) light coloured trace fossils in dark sediment (LID ichnofabric) and (b) dark coloured trace fossils in light sediment (DIL ichnofabric). Ichnofabric analysis suggests multiple colonization, complex tiering, and multilayer tiering. The LID Ichnofabric exposed at Kalapathar reveals three tiers, a diverse shallow tier and a moderately low diverse middle and deep tiers. At the Lacam Point section, in contrast, the LID ichnofabric is represented by condensation of the tiers and the absence of shallow tiers. The DIL ichnofabric at the Kalapathar section seems to be more expanded and is represented by four tiers with extensive bioturbation. Ichnofabric analysis supports deposition of the chalk sediments in a lower bathyal paleoenvironment and suggests that organic matter, pore water, and bottom-water oxygenation were the main controlling factors. Thus, the ichnofabric analysis of the Early-Middle Miocene Inglis Formation gives first-hand information regarding the poorly known chalk facies of the Andaman and Nicobar Islands pre-Bengal fan stage of the Indian plate.
. Ichnofabric analysis of bathyal chalks: The Miocene Inglis Formation of the Andaman and Nicobar Islands, India[J]. , 2021, 10(4): 494-508.
. Ichnofabric analysis of bathyal chalks: The Miocene Inglis Formation of the Andaman and Nicobar Islands, India[J]. Journal of Palaeogeography, 2021, 10(4): 494-508.
[1] Allen R., Carter A., Najman Y., Bandopadhyay P.C., Chapman H.J., Bickle M.J., Gerring C., 2008. New constraints on the sedimentation and uplift history of the Andaman-Nicobar accretionary prism, South Andaman Island.Geological Society of America Special Paper, 436, 223-255. [2] Anuj C.S., Koley T., Parhi S., 2016. Trace fossils of the Palaeogene sequences of North Andaman Island and their palaeoenvironmental significance.Indian Journal of Geoscience, 703(4), 205-218. [3] Badve B.M., Ghare M.A., Rajshekher C., 1984. On the age of the ejected material from mud volcano of Baratang Island, Andaman.Current Science, 53, 814-815. [4] Bandopadhyay P.C., Carter A., 2017a. Geological Framework of the AndamaneNicobar Islands, vol. 471. Geological Society London, Memoirs, pp. 75-93. [5] Bandopadhyay P.C., Carter A., 2017b. The Archipelago Group: Current Understanding, vol. 471. Geological Society London, Memoirs, pp. 153-166. [6] Bandopadhyay P.C., Chakrabarti U., Roy A., 2009. First report of trace fossils from Palaeogene succession Namunagarh grit of Andaman and Nicobar Islands.Journal of Geological Society of India, 732, 261-267. [7] Brink K., Arnone R., Coble P., Flagg C., Jones B., Kindle J., Lee C., Phinney D., Wood M., Yentsch C., Young D., 1998. Monsoons boost biological productivity in Arabian Sea.Eos, Transactions of the American Geophysical Union, 7913, 165-169. [8] Bromley R.G.,1991. Zoophycus: Strip mine, refuse dump, cache or sewage farm? Lethaia, 24, 460-462. [9] Brongniart A.,1823. Observations sur les Fucoids. Societe d'Historie Naturelle de Paris, 1, 301-320 (Paris). [10] Brongniart A.,1828. Histoire des vegetaux fossiles, vol. 1, pp. 1-488 (Paris). [11] Buatois L.A., Máangano M.G., 2011. Ichnology: Organism-Substrate Interactions in Space and Time. Cambridge University Press, p. 347. [12] Chakraborty A., Bown P.R., Ghosh A.K., Young J.R., 2017. Calcareous nannofossils from the Miocene of the Andaman and Nicobar Islands, India: Biostratigraphic and paleoecological perspectives. In: 16th international nannoplankton association meeting, September, 2017, Greece. Journal of Nannoplankton Research, 37, 47. [13] Chakraborty A., Ghosh A.K., Dey R., Saxena S., Mazumder A., 2019. Record of the Miocene climate optimum in the northeast Indian ocean: Evidence from the microfossils.Palaeobiodiversity and Palaeoenvironments, 992, 159-175. [14] Chamberlain C.K.,1975. Trace fossils in DSDP cores of the Pacific. Journal of Paleontology, 49(6), 1074-1096. [15] Clemens S.C., Kuhnt W., LeVay L.J., 2015. The expedition 353 Scientists 2015 expedition 353 Preliminary report: Indian monsoon rainfall. International Ocean Discovery Program, 353. https://doi.org/10.14379/iodp.pr.353.2015. [16] Curray J.R.,2005. Tectonics and history of the Andaman sea region.Journal of Asian Earth Sciences, 251, 187-232. [17] Dashtgard S.E., Gingras M.K., Pemberton S.G., 2008. Grain-size controls on the occurrence of bioturbation.Palaeogeography, Palaeoclimatology, Palaeoecology, 257, 224-243. [18] Desai B.G., Shukla R., Saklani R.D., 2010. Ichnology of the early Cambrian tal group, Nigalidhar syncline, lesser Himalaya, India. Ichnos, 174, 233-245. [19] Droser M.L., Bottjer D.J., 1991. Trace fossils and ichnofabrics in Leg 119 cores. In: Barron, J., Larsen, B., et al. (Eds.), Proceedings of the Ocean Drilling Program, vol. 119. Scientific Results, pp. 635-641. [20] Ekdale A.A., Bromley R.G., 1984a. Comparative ichnology of shelf-sea and deep-sea chalk.Journal of Paleontology, 58(2), 322-332. [21] Ekdale A.A., Bromley R.G., 1984b. Cretaceous chalk ichnofacies in northern Europe.Geobios, 17, 201-204. [22] Ekdale A.A., Bromley R.G., 1991. Analysis of composite ichnofabrics; an example in Uppermost Cretaceous chalk of Denmark.Palaios, 63, 232-249. [23] Ekdale A.A.,1977. Trace fossils in worldwide deep sea drilling Project cores. In: Crimes, T.P., Harper, J.C. (Eds.), Trace Fossils 2, vol. 9. Geological Journal Special Isssue, pp. 163-182. [24] Ekdale A.A.,1978. Trace fossils in Leg 42A cores. In: Hs, K.J., Montadert, L., et al. (Eds.), Initial Reports Of the Deep Sea Drilling Project 42, pp. 821-827. [25] Ekdale A.A.,1980. Trace fossils in deep sea drilling Project leg 58 cores. In: de Vries Klein, G., Kobyashi, K., et al. (Eds.), Initial Reports Of the Deep Sea Drilling Project 58, pp. 601-605. [26] Fabricius I.L.,2007. chalk: Composition, diagenesis and physical properties.Bulletin of the Geological Society of Denmark, 55, 97-128. [27] Fu S.,1991. Funktion. Verhalten und Einteilung fucoider und lophocteniider Lebensspuren, vol. 135. Courier Forschungs-Institut Senckenberg, pp. 1-79. [28] Karunakaran C., Roy K.K., Saha S.S., 1968. Tertiary sedimentation in the Andaman-Nicobar Geosyncline.Journal of Geological Society of India, 9(1), 32-39. [29] Knaust D.,2017. Atlas of Trace Fossils in Well Core: Appearance, Taxonomy and Interpretation. Springer, p. 219. [30] Knaust D., Warchoł M., Kane I.A., 2014. Ichnodiversity and ichnoabundance: revealing depositional trends in a confined turbidite system.Sedimentology, 617, 2218-2267. [31] Locklair R.E., Savrda C.E., 1998. Ichnology of rhythmically bedded Demopolis chalk Upper Cretaceous, Alabama; Implications for paleoenvironment, depositional cycle origins, and trackmaker behaviour.Palaios, 135, 423-436. [32] Meadows A., Meadows P.S., West F.J., Murray J.M., 2000. Bioturbation, geochemistry and geotechnics of sediments affected by the oxygen minimum zone on the Oman continental slope and abyssal plain, Arabian Sea.Deep-Sea Research Part II: Topical Studies in Oceanography, 471(2), 259-280. [33] Nelson C.S.,1985. Bioturbation in middle bathyal, Cenozoic nanno-fossil oozes and chalks, southwest Pacific. In: Kennett, J.P., von der Borch, C.C., et al. (Eds.), Initial Reports of the Deep-Sea Drilling Project, vol. 90, pp. 1189-1200. [34] Pandey J., Agarwal R.P., Dave A., Maithani A., Trivedi K.B., Srivastava A.K., Singh D.N., 1992. Geology of Andaman.Bulletin of Oil and Natural Gas Commission, 29, 19-103. [35] Parrish J.T., Droser M.L., Bottjer D.J., 2001. A Triassic upwelling zone: The Shublik formation, Arctic Alaska, USA.Journal of Sedimentary Research, 712, 272-285. [36] Patel S.J., Desai B.G., 2009. Animal-sediment relationship of the crustaceans and polychaetes in the intertidal zone around Mandvi, Gulf of Kachchh, Western India.Journal of the Geological Society of India, 742, 233-259. [37] Pickering K.T., Hiscott R.N., 2015. Deep Marine Systems: Processes, Deposits, Environments, Tectonics and Sedimentation. John Wiley and Sons, p. 674. [38] Pickering K.T., Stow D.W., Watson M., Hiscott R.N., 1986. Deep-water facies, processes and models: A review and classification scheme for modern and ancient sediments.Earth-Science Reviews, 23, 75-174. [39] Rai J.,2021, Personal telephonic communicaiton. Rieth, A., 1932. Neue Funde spongeliomorpher Fucoiden aus dem Jura Schwabens. In: Geologische und Palæontologische Abhandlungen, vol. 19. Neue Folge, pp. 257-294. [40] Rodríguez-Tovar F.J., Uchman A., Martín-Algarra A., O'Dogherty L., 2009. Nutrient spatial variation during intrabasinal upwelling at the CenomanianeTuronian oceanic anoxic event in the westernmost Tethys: An ichnological and facies approach.Sedimentary Geology, 2151(4), 83-93. [41] Savrda C.E., Bottjer D.J., 1989. Trace-fossil model for reconstructing oxygenation histories of ancient marine bottom waters: Application to Upper Cretaceous Niobrara Formation, Colorado.Palaeogeography, Palaeoclimatology, Palaeoecology, 741(2), 49-74. [42] Savrda C.E.,2012. Chalk and related deep-marine carbonates. In: Knaust, D., Bromley, R.G. (Eds.), Trace Fossils as Indicators of Sedimentary Environments. in: Developments in Sedimentology, vol. 64. Elsevier, pp. 777-806. [43] Scholle P.A., Bebout D.G., Moore C.H., 1983. Carbonate Depositional Environments, vol. 33. AAPG Memoir, p. 708. [44] Schulz H., Von Rad U., Von Stackelberg U., 1996. Laminated Sediments from the Oxygen-Minimum Zone of the Northeastern Arabian Sea, vol. 1161. Geological Society of London, Special Publication, pp. 185-207. [45] Seely D.R., Vail P.R., Walton G.G., 1974. Trench slope model. In: Burk, C.A. (Ed.), The Geology of Continental Margins 249-260. Springer, Berlin, Heidelberg. [46] Sharma V., Srinavasan M.S., 2007. Geology of Andaman-Nicobar: The Neogene. Capital Publishing Company, p. 164. [47] Singh A.D., Jung S.J., Darling K., Ganeshram R., Ivanochko T., Kroon D., 2011. Productivity collapses in the Arabian Sea during glacial cold phases. Paleoceanography, 26 PA3210, 1-10. [48] Smith C.R., Levin L.A., Hoover D.J., McMurtry G., Gage J.D., 2000. Variations in bioturbation across the oxygen minimum zone in the northwest Arabian Sea.Deep-Sea Research Part II: Topical Studies in Oceanography, 471(2), 227-257. [49] Smitha A., Joseph A.K., Jayaram C., Balachand A.N., 2014. Upwelling in the southeastern Arabian sea as evidenced by Ekman mass transport using wind observations from oceansat-II scaterometer.Indian Journal of Geo-Marine Science, 431, 111-116. [50] Srinivasan M.S., Azmi R.J., 1976a. Contribution to the stratigraphy of Neill Island, Ritchie's Archipelago, Andaman sea. In: Srinivasan, M.S. (Ed.), Proceedings of VI Indian Colloquim on Micropaleontology and Stratigraphy, Varanasi, pp. 283-301. [51] Srinivasan M.S., Azmi R.J., 1976b. New development in the late Cenozoic lithostratigraphy of Andaman and Nicobar Islands, Bay of Bengal. In: Srinivasan, M.S. (Ed.), Proceedings of VI Indian Colloquim on Micropaleontology and Stratigraphy, Varanasi, pp. 302-327. [52] Srinivasan M.S., Azmi R.J., 1976c. Paleobathymetric trends of the late Cenozoic foraminiferal assemblages of Ritchie's Archipelago. In: Srinivasan, M.S. (Ed.), Proceedings of VI Indian Colloquim on Micropaleontology and Stratigraphy, Varanasi, pp. 328-354. [53] Srinivasan M.S., Kennett J.P., 1981. Neogene planktonic foraminiferal biostratigraphy and evolution: Equatorial to subantarctic, South Pacific.Marine Micropaleontology, 65(6), 499-533. [54] Summerhayes C.P.,1983. Sedimentation of organic matter in upwelling regimes. In: Thiede, J., Suess, E. (Eds.), Coastal Upwelling, its Sediment Record, Part B: Sedimentary Records of Ancient Coastal Upwelling. Plenum, New York, pp. 29-72. [55] Taylor A., Goldring R., Gowland S., 2003. Analysis and application of ichnofabrics.Earth-Science Reviews, 603(4), 227-259. [56] Uchman A.,2009. The Ophiomorpha rudis ichnosubfacies of the Nereites ichnofacies: Characteristics and constraints.Palaeogeography, Palaeoclimatology, Palaeoecology, 2761(4), 107-119. [57] Uchman A., Wetzel A., 2011. Deep-sea ichnology: the relationships between depositional environment and endobenthic organisms. In: Developments in Sedimentology, vol. 63. Elsevier, pp. 517-556. [58] Uchman A.,1999. Ichnology of the rhenodanubian flysch lower Cretaceous-Eocene in Austria and Germany.Beringeria, 25, 65-171. [59] Werner F., Wetzel A., 1982. Interpretation of biogenic structures in oceanic sediments.Bulletin of the Institution of Geologie-Bassin Aquitaine, 31, 275-288. [60] Wetzel A.,1983. Biogenic sedimentary structures in a modern upwelling region: Northwest African continental margin. In: Coastal Upwelling and its Sediment Record, Part B, Sedimentary Records of Ancient Coastal Upwelling. Plenum, New York, pp. 123-144. [61] Wetzel A.,1987. Ichnofabrics in Eocene to Maestrichtian Sediments fromDeep Sea Drilling Project Site 605, off NewJersey Coast, vol. 92. Initial Reports of the DSDP, pp. 825-835. [62] Wetzel A., Wijayananda N.P., 1990. Biogenic sedimentary structures in outer Bengal Fan deposits drilled during Leg 116. In: Cochran, J.R., Stow, D.A.V. (Eds.), Proceedings of the Ocean Drilling Project, Scientific Results, vol. 116, pp. 15-24. [63] Wetzel A., Tjallingii R., Wiesner M.G., 2011. Bioturbational structures record environmental changes in the upwelling area off Vietnam South China Sea for the last 150,000 years.Palaeogeography, Palaeoclimatology, Palaeoecology, 312(3-4), 256-267.
2021, Vol. 10 
