Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives
Extended shallow carbonate platform, pelagic, and drift deposits were drilled during International Ocean Discovery Program (IODP) Expedition 359 in the Inner Sea of the Maldives. These sediments yield rich and well-diversified benthic, planktonic foraminiferal and nannofossil assemblages spanning fr...
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2022
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ftdoajarticles:oai:doaj.org/article:3c763a3c626444aa960c5eaada3d71f5 2023-05-15T18:00:49+02:00 Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives Silvia Spezzaferri Jeremy Young Stephanie Stainbank Giovanni Coletti Dick Kroon 2022-06-01T00:00:00Z https://doi.org/10.3390/geosciences12060239 https://doaj.org/article/3c763a3c626444aa960c5eaada3d71f5 EN eng MDPI AG https://www.mdpi.com/2076-3263/12/6/239 https://doaj.org/toc/2076-3263 doi:10.3390/geosciences12060239 2076-3263 https://doaj.org/article/3c763a3c626444aa960c5eaada3d71f5 Geosciences, Vol 12, Iss 239, p 239 (2022) IODP Expedition 359 Site U1468A biostratigraphy benthic planktonic foraminifera and calcareous nannofossils age model Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.3390/geosciences12060239 2022-12-31T03:14:24Z Extended shallow carbonate platform, pelagic, and drift deposits were drilled during International Ocean Discovery Program (IODP) Expedition 359 in the Inner Sea of the Maldives. These sediments yield rich and well-diversified benthic, planktonic foraminiferal and nannofossil assemblages spanning from the early Oligocene to the Recent. We present here the shore-based revised integrated biostratigraphy of these microfossil groups at IODP Hole 359-U1468A together with the paleobathymetric reconstruction. Our data suggests the presence of a late Oligocene carbonate platform, marked by the shallowest water depths of the entire sequence of around 80 m. This carbonate platform sequence occurred from around 29 Ma, the extrapolated minimum age estimate, at least up to 27.5 Ma and possibly up to 25.4 Ma. Up the sequence, similar carbonate production conditions occurred until 22.5 Ma across the Oligocene–Miocene transition, equated at 23.04 Ma, with increased water depths >120 m. Notably, in the time interval approximately from 24 to 21.5 Ma, orbitally induced sapropel layers indicate a change of open to restricted circulation. However, at around 22.5 Ma, pelagic deposition at a distal slope occurred with sedimentation rates of 3 cm/years. This initially occurred in water depths of >350 m but gradually reached deposition in water depths of >500 m, which persisted from 21.12 Ma until approximately the extrapolated age of 12.8 Ma. Sedimentation rates gradually increased to 10.5 cm/1000 years at around 450 m below sea floor, marking the initiation of the drift sequence as identified in seismic lines with an age estimate of 12.8 Ma. The initiation of the drift sequence is also marked by a drastic decrease in the preservation of benthic and planktonic foraminifera from good to very poor at around 12.8 Ma. The drift sequence essentially continued to the present day but was interrupted by two events: the deposition of distinct shallow water benthic shoals and a large hiatus. From 12.8 Ma, a shallowing upward bathymetry ... Article in Journal/Newspaper Planktonic foraminifera Directory of Open Access Journals: DOAJ Articles Geosciences 12 6 239 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
IODP Expedition 359 Site U1468A biostratigraphy benthic planktonic foraminifera and calcareous nannofossils age model Geology QE1-996.5 |
spellingShingle |
IODP Expedition 359 Site U1468A biostratigraphy benthic planktonic foraminifera and calcareous nannofossils age model Geology QE1-996.5 Silvia Spezzaferri Jeremy Young Stephanie Stainbank Giovanni Coletti Dick Kroon Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives |
topic_facet |
IODP Expedition 359 Site U1468A biostratigraphy benthic planktonic foraminifera and calcareous nannofossils age model Geology QE1-996.5 |
description |
Extended shallow carbonate platform, pelagic, and drift deposits were drilled during International Ocean Discovery Program (IODP) Expedition 359 in the Inner Sea of the Maldives. These sediments yield rich and well-diversified benthic, planktonic foraminiferal and nannofossil assemblages spanning from the early Oligocene to the Recent. We present here the shore-based revised integrated biostratigraphy of these microfossil groups at IODP Hole 359-U1468A together with the paleobathymetric reconstruction. Our data suggests the presence of a late Oligocene carbonate platform, marked by the shallowest water depths of the entire sequence of around 80 m. This carbonate platform sequence occurred from around 29 Ma, the extrapolated minimum age estimate, at least up to 27.5 Ma and possibly up to 25.4 Ma. Up the sequence, similar carbonate production conditions occurred until 22.5 Ma across the Oligocene–Miocene transition, equated at 23.04 Ma, with increased water depths >120 m. Notably, in the time interval approximately from 24 to 21.5 Ma, orbitally induced sapropel layers indicate a change of open to restricted circulation. However, at around 22.5 Ma, pelagic deposition at a distal slope occurred with sedimentation rates of 3 cm/years. This initially occurred in water depths of >350 m but gradually reached deposition in water depths of >500 m, which persisted from 21.12 Ma until approximately the extrapolated age of 12.8 Ma. Sedimentation rates gradually increased to 10.5 cm/1000 years at around 450 m below sea floor, marking the initiation of the drift sequence as identified in seismic lines with an age estimate of 12.8 Ma. The initiation of the drift sequence is also marked by a drastic decrease in the preservation of benthic and planktonic foraminifera from good to very poor at around 12.8 Ma. The drift sequence essentially continued to the present day but was interrupted by two events: the deposition of distinct shallow water benthic shoals and a large hiatus. From 12.8 Ma, a shallowing upward bathymetry ... |
format |
Article in Journal/Newspaper |
author |
Silvia Spezzaferri Jeremy Young Stephanie Stainbank Giovanni Coletti Dick Kroon |
author_facet |
Silvia Spezzaferri Jeremy Young Stephanie Stainbank Giovanni Coletti Dick Kroon |
author_sort |
Silvia Spezzaferri |
title |
Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives |
title_short |
Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives |
title_full |
Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives |
title_fullStr |
Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives |
title_full_unstemmed |
Improved Planktonic, Benthic Foraminiferal and Nannofossil Biostratigraphy Aids the Interpretation of the Evolution at Hole U1468A: IODP Expedition 359, the Maldives |
title_sort |
improved planktonic, benthic foraminiferal and nannofossil biostratigraphy aids the interpretation of the evolution at hole u1468a: iodp expedition 359, the maldives |
publisher |
MDPI AG |
publishDate |
2022 |
url |
https://doi.org/10.3390/geosciences12060239 https://doaj.org/article/3c763a3c626444aa960c5eaada3d71f5 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
Geosciences, Vol 12, Iss 239, p 239 (2022) |
op_relation |
https://www.mdpi.com/2076-3263/12/6/239 https://doaj.org/toc/2076-3263 doi:10.3390/geosciences12060239 2076-3263 https://doaj.org/article/3c763a3c626444aa960c5eaada3d71f5 |
op_doi |
https://doi.org/10.3390/geosciences12060239 |
container_title |
Geosciences |
container_volume |
12 |
container_issue |
6 |
container_start_page |
239 |
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1766170060782567424 |