Diatom isotope data (δ¹⁸Odiatom and d30Sidiatom) from IODP Site 303-U1304 (North Atlantic)

The Last Interglacial (LIG), corresponding to Marine Isotope Stage (MIS) 5e, provides a reference of interglacial climate variability in the absence of anthropogenic forcing. Using an expanded section of the LIG gained at Integrated Ocean Drilling Program Site U1304 in the Subarctic Atlantic, we dem...

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Bibliographic Details
Main Authors: Romero, Oscar E, Swann, George E A, Hodell, David A, Helmke, Peer, Rey, Daniel, Rubio, Belen
Format: Dataset
Language:English
Published: PANGAEA 2011
Subjects:
303-U1304A
303-U1304B
Diatoms
δ18O
δ30Si
DRILL
Drilling/drill rig
DSDP/ODP/IODP sample designation
Event label
Exp303
Integrated Ocean Drilling Program / International Ocean Discovery Program
IODP
Joides Resolution
North Atlantic Climate 1
Sample code/label
North Atlantic
Subarctic
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.856094
https://doi.org/10.1594/PANGAEA.856094
Description
Summary:The Last Interglacial (LIG), corresponding to Marine Isotope Stage (MIS) 5e, provides a reference of interglacial climate variability in the absence of anthropogenic forcing. Using an expanded section of the LIG gained at Integrated Ocean Drilling Program Site U1304 in the Subarctic Atlantic, we demonstrate that the early MIS 5e was marked by oceanographic conditions conducive for high diatom production and accumulation. The appearance of diatom-dominated laminated oozes ~3 k.y. after the beginning of MIS 5e at ca. 125 ka coincides with a shift to higher d30Sidiat values together with the dominance of Thalassiothrix longissima, indicative of increased nutrient availability and silicic acid utilization in surface waters. Though the Subarctic Front provided the physical conditions for high diatom production and deposition, these processes alone are insufficient to explain the high rates of siliceous productivity and the formation of diatomaceous sediments. Instead, the additional presence of an increased nutrient pool provided by Subantarctic Mode Water played the decisive role in initiating and sustaining diatom production. The high diatom productivity and the occurrence of diatomaceous sediments in the late Quaternary challenge the current hypothesis of a silica-depleted North Atlantic during the LIG.

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