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Past bottom current velocities are usually determined from the sortable silt (SS) fraction of sediments. This method yields precise results, but the work associated with the preparation for and analysis of SS is very time consuming. Using data and samples from Site U1537, which was drilled during International Ocean Discovery Program (IODP) Expedition 382 (Iceberg Alley and Subantarctic Ice and Ocean Dynamics), we followed a method that allows for the reconstruction of bottom current velocities on long and highly resolved sediment records, as typically recovered during an IODP expedition. Here, we present discrete measurements of SS from Site U1537 that were used to convert X-ray fluorescence (XRF) core scanner Zr/Rb data into SS and ultimately into bottom current velocities. The use of XRF-derived SS data and current speeds allows us to generate a near-continuous high-resolution record for the past 200 ky. Because Site U1537 is located close to the Southern Antarctic Circumpolar Current Front (SACCF), this long-term reconstruction allows us to analyze and understand changes in the location of the SACCF.
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This content will become publicly available on November 10, 2026
Pliocene to modern Southern Ocean diatom biostratigraphy revised using samples from IODP Expedition 382
Abstract. Biostratigraphy is frequently used to generate age models and is significant to understanding the rate and timing of Cenozoic climate change. Records from the Southern Ocean (SO) are particularly valuable in understanding the past behavior of the Antarctic Ice Sheet, whereby clues to this behavior can be gained from the presence and composition of preserved microfossils. Diatoms, a nearly ubiquitous group of microalgae that make cell walls out of opal, preserve well in Southern Ocean sediments and have been used extensively in Southern Ocean biostratigraphy. Here, we present an updated diatom biostratigraphy of the Southern Ocean extending 3.3 Myr from sediments recovered during International Ocean Discovery Program (IODP) Expedition 382 “Iceberg Alley” Site U1537. Furthermore, we compare a tuned age model to a paleomagnetic-based age model to provide two independent estimates of ages of these datums with quantified uncertainty. The high sedimentation rate found at Site U1537 allows detailed age assessment, allowing the generation of more finely tuned age models in Southern Ocean sediments.
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- PAR ID:
- 10651236
- Publisher / Repository:
- Journal of Micropalaeontology
- Date Published:
- Journal Name:
- Journal of Micropalaeontology
- Volume:
- 44
- Issue:
- 2
- ISSN:
- 2041-4978
- Page Range / eLocation ID:
- 497 to 507
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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