A highly diverse living benthic foraminiferal assemblage in the oxygen deficient zone of the southeastern Arabian Sea

AbstractWe have analysed a 6100-year record of benthic and planktonic foraminifera from inner neritic sediments from Core SK291/GC13, off the Goa coast, eastern Arabian Sea, to understand the response of benthic foraminifera to shallow-marine processes. The benthic foraminiferal assemblage is dominated by Nonion cf. asterizans, Ammonia beccarii, A. gaimardii and Virgulinella fragilis, which have been selected on the basis of a population of 10% or more in any three samples analysed. The planktonic foraminiferal population is sporadic and rare, with Globigerinoides ruber as the predominant species showing a variable trend. The foraminiferal proxies combined with total organic carbon (wt%) and δ13C and δ18O values of Ammonia gaimardii suggest distinct variations, indicating changes in productivity and salinity in the shallow eastern Arabian Sea. The coastal waters off Goa were relatively warmer and less saline between 6100 and 4600, or perhaps to 4200, calibrated years before the present (cal yr BP), corresponding to a stronger monsoon in South and East Asia. The shallow sea was cooler from ~4200 to 2600 cal yr BP in the study area, coinciding with a lower sea surface temperature in the northeastern Arabian Sea and an arid phase in the Indian subcontinent. From 2900 to 2600 cal yr BP the study core exhibits the impacts of short-term cold events, which have earlier been observed in the northeastern Arabian Sea, off Pakistan. During the Little Ice Age, the shallow sea off Goa was less productive.

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Influence of upwelling on the chaetognath community along the Southeastern Arabian Sea

Wetlands Ecology and Management ◽

10.1007/s11273-020-09773-6 ◽

2021 ◽

Author(s):

Aishwarya Purushothaman ◽

Lathika Cicily Thomas ◽

S. Bijoy Nandan ◽

K. B. Padmakumar

Keyword(s):

Arabian Sea ◽

Southeastern Arabian Sea

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Paleoproductivity shifts since the last 130 ka off Lakshadweep, Southeastern Arabian Sea

Regional Studies in Marine Science ◽

10.1016/j.rsma.2021.101776 ◽

2021 ◽

Vol 44 ◽

pp. 101776

Author(s):

Kannaiyan Neelavannan ◽

S.M. Hussain ◽

N. Mohammed Nishath ◽

Hema Achyuthan ◽

S. Veerasingam ◽

...

Keyword(s):

Arabian Sea ◽

Southeastern Arabian Sea

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Seafloor spreading magnetic anomalies in the southeastern Arabian Sea

Marine Geology ◽

10.1016/0025-3227(95)00089-h ◽

1995 ◽

Vol 128 (1-2) ◽

pp. 105-114 ◽

Cited By ~ 8

Author(s):

A.K. Chaubey ◽

G.C. Bhattacharya ◽

D.Gopala Rao

Keyword(s):

Arabian Sea ◽

Magnetic Anomalies ◽

Seafloor Spreading ◽

Southeastern Arabian Sea

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Benthic foraminiferal assemblage turnover during intensification of the Northern Hemisphere glaciation in the Piacenzian Punta Piccola section (Southern Italy)

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2012.03.009 ◽

2012 ◽

Vol 333-334 ◽

pp. 59-74 ◽

Cited By ~ 7

Author(s):

Franca Sgarrella ◽

Valentino Di Donato ◽

Rodolfo Sprovieri

Keyword(s):

Northern Hemisphere ◽

Southern Italy ◽

Foraminiferal Assemblage ◽

Benthic Foraminiferal Assemblage

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The Upper Cretaceous foraminiferal record of IODP Site U1512 (Great Australian Bight, Indian Ocean)

10.5194/egusphere-egu21-7844 ◽

2021 ◽

Author(s):

Erik Wolfgring ◽

Michael A. Kaminski ◽

Anna Waśkowska ◽

Maria Rose Petrizzo ◽

Eun Young Lee ◽

...

Keyword(s):

Indian Ocean ◽

Ocean Circulation ◽

Planktonic Foraminifera ◽

Late Eocene ◽

Foraminiferal Assemblage ◽

Benthic Foraminiferal Assemblage ◽

International Ocean Discovery Program ◽

Foraminiferal Record ◽

Great Australian Bight ◽

Microfossil Assemblage

Site U1512 was drilled during Expedition 369 of the International Ocean Discovery Program (IODP), which is located in the Great Australian Bight, southern Indian Ocean. It provides exceptional insights into the benthic foraminiferal biostratigraphy and paleoecology of a high southern latitude restricted marginal marine basin during the Late Cretaceous hot greenhouse climate and the rifting between Australia and Antarctica. The sedimentary sequence recovered at Site U1512 presents a rare record of a deep water agglutinated foraminifera (DWAF) community from the Southern High Latitudes. The Cretaceous record at Site U1512 covers the lower Turonian through Santonian (nannofossil zones UC8b to UC12/CC10b to CC16, H. helvetica to Marginotruncana spp. - Planoheterohelix papula - Globotruncana linneana planktonic foraminifera zones). Diverse benthic foraminiferal assemblages yield many new taxa that are yet to be described.Agglutinated forms dominate the assemblage in most intervals. In lower to mid Turonian and Santonian strata, calcareous benthic as well as planktonic foraminifera are frequent. Abundant radiolaria are recovered from the mid Turonian, and they increase up-section and exceed 50% of the microfossil assemblage. We documented a diverse benthic foraminiferal assemblage consisting of 162 taxa (110 agglutinated and 52 calcareous). The most common taxa of the DWAF assemblage are tubular (i.e., Kalamopsis grzybowskii, Bathysiphon spp.) and planispiral forms (i.e., Ammodiscus spp., Haplophragmoides spp., Buzasina sp., Labrospira spp.).The Turonian strata yield highly abundant Bulbobaculites problematicus and Spiroplectammina navarroana. The presence of the agglutinated foraminiferal marker taxa Uvigerinammina jankoi and Bulbobaculites problematicus provides a tie-point to the Tethyan DWAF biozonation of Geroch and Nowak (1984). The composition of foraminiferal assemblages and the increase in radiolaria abundance suggest unstable environmental conditions at Site U1512 during the early Turonian through Santonian. These characteristics refer to changes in bathymetry associated with changing ocean chemistry. Results of quantitative analyses of the benthic foraminiferal assemblages indicate a restricted paleoenvironmental regime, dictated by changes in paleobathymetry, unstable patterns in ocean circulation, and the discharge of a nearby river delta system.References: Geroch, S., Nowak, K., 1984. Proposal of zonation for the Late Tithonian &#8211; late Eocene. based upon arenaceous Foraminifera from the Outer Carpathians, Poland, 225-239, In: Oertli, H.J. (Ed.), Benthos &#180;83; 2nd international 915 Symposium on Benthic Foraminifera, Pau (France) April 11-15, 1983, Elf Aquitaine, ESO REP and TOTAL CFP, Pau and Bordeaux.&#160;

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Nummulites Fayumensis N. Sp. and Nummulites Tenuissimus N. Sp. from Munquar El-rayan, Fayum, Egypt

The Journal of Foraminiferal Research ◽

10.2113/gsjfr.48.1.17 ◽

2018 ◽

Vol 48 (1) ◽

pp. 17-28 ◽

Cited By ~ 1

Author(s):

Safia Al Menoufy ◽

Mohamed Boukhary

Keyword(s):

New Species ◽

Foraminiferal Assemblage ◽

Shallow Marine ◽

Marine Facies ◽

Benthic Foraminiferal Assemblage ◽

Insight Into ◽

Important Site

Abstract Nummulites fayumensis n. sp. and Nummulites tenuissimus n. sp. are described from the Munqar El-Rayan Section, Fayum, Egypt. Nummulites tenuissimus belongs to the N. partschi group, while N. fayumensis belongs to the N. gizehensis group, based on diameter and protoconch sizes, septal shape and granulations. Both new species are of Lutetian age, assigned to SBZ14/15, and encountered in shallow-marine facies. Wadi El-Rayan is an important site for vertebrate fossils in Egypt and the abundant larger benthic foraminiferal assemblage provides insight into paleoenvironmental parameters associated with the deposition of Eocene-age rock units of the Munqar El-Rayan Section.

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