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Palaeoceanographic implications of abundance and mean proloculus diameter of benthic foraminiferal speciesEpistominella exigua in sub-surface sediments from distal Bay of Bengal fan

  • R. Saraswat
  • R. Nigam
  • Lea Barreto
Article

Abstract

Temporal variation in abundance and mean proloculus diameter of the benthic foraminiferal speciesEpistominella exigua has been reconstructed over the last ∼ 50,000 yr BP, from a core collected from the distal Bay of Bengal fan, to assess its potential application in palaeoceanographic reconstruction studies. The down-core variation shows significant change in abundance ofE. exigua during the last ∼ 50,000 yr BP. In view of the present day abundance of this species from areas with strong seasonal organic matter supply, we conclude that at ∼ 7, ∼ 22, ∼ 33 and ∼ 46kyr BP, strong seasonality prevailed in the distal Bay of Bengal fan, probably indicating either strong or prolonged north-east monsoon or weakened south-west monsoon. For the first time, a strong correlation is observed in abundance and mean proloculus diameter ofE. exigua. Based on coherent variation in mean proloculus diameter and abundance, it is postulated that mean proloculus diameter can also be used to infer increased seasonality in organic matter production, thus variation in strength or duration of monsoon. Thus, this study establishes that the down-core variation in the abundance and mean proloculus diameter ofEpistominella exigua can be used to infer past climatic variations from the distal Bay of Bengal fan.

Keywords

Epistominella exigua abundance mean proloculus diameter Bengal fan monsoon 

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Copyright information

© Indian Academy of Sciences 2005

Authors and Affiliations

  • R. Saraswat
    • 1
  • R. Nigam
    • 1
  • Lea Barreto
    • 1
  1. 1.Micropaleontology LaboratoryNational Institute of OceanographyGoaIndia

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