Barron, John A (1992): Distribution of Pliocene diatom faunas in the Northwest Pacific [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.683672, Supplement to: Barron, JA (1992): Pliocene paleoclimatic interpretation of DSDP Site 580 (NW Pacific) using diatoms. Marine Micropaleontology, 20(1), 23-44, https://doi.org/10.1016/0377-8398(92)90007-7
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Abstract:
High-resolution quantitative diatom data are tabulated for the early part of the late Pliocene ( 3.25 to 2.08 Ma ) at DSDP Site 580 in the northwestern Pacific. Sample spacing averages 11 k.y. between 3.1 and 2.8 Ma, but increases to 14 to 19 k.y. prior to 3.1 Ma and after 2.8 Ma. Q-mode factor analysis of the middle Pliocene assemblage reveals four factors which explain 92.4% of the total variance of the 47 samples studied between 3.25 and 2.55 Ma. Three of the factors are closely related to modern subarctic, transitional, and subtropical elements, while the fourth factor, which is dominated by Coscinodiscus marginatus and the extinct Pliocene species Neodenticula kamtschatica, appears to correspond to a middle Pliocene precursor of the subarctic water mass.
Knowledge of the modern and generalized Pliocene paleoclimatic relationships of various diatom taxa is used to generate a paleoclimate curve ("Twt") based on the ratio of warm-water (subtropical) to cold-water diatoms with warm-water transitional taxa (Thalassionema nitzschioides, Thalassiosira oestrupii, and Coscinodiscus radiatus) factored into the equation at an intermediate (0.5) value. The "Twt" ratios at more southerly DSDP Sites 579 and 578 are consistently higher (warmer) than those at Site 580 throughout the Pliocene, suggesting the validity of the ratio as a paleoclimatic index.
Diatom paleoclimatic data reveal a middle Pliocene (3.1 to 3.0 Ma) warm interval at Site 580 during which paleotemperatures may have exceeded maximum Holocene values by 3 °- 5.5 °C at least three times. This middle Pliocene warm interval is also recognized by planktic foraminifers in the North Atlantic, and it appears to correspond with generalized depleted oxygen isotope values suggesting polar warming.
The diatom "Twt" curve for Site 580 compares fairly well with radiolarian and silicoflagellate paleoclimatic curves for Site 580, planktic foraminiferal sea-surface temperature estimates for the North Atlantic, and benthic oxygen isotope curves for late Pliocene, although higher resolution studies on paired samples are required to test the correspondence of these various paleoclimatic indices.
Project(s):
Deep Sea Drilling Project (DSDP)
Coverage:
Latitude: 41.624500 * Longitude: 153.976300
Date/Time Start: 1982-06-06T00:00:00 * Date/Time End: 1982-06-06T00:00:00
Event(s):
86-580 * Latitude: 41.624500 * Longitude: 153.976300 * Date/Time: 1982-06-06T00:00:00 * Elevation: -5375.0 m * Penetration: 155.3 m * Recovery: 140.4 m * Location: North Pacific * Campaign: Leg86 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 17 cores; 155.3 m cored; 0 m drilled; 90.4 % recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
3 datasets
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Datasets listed in this publication series
- Barron, JA (1992): (Table 3) Distribution of diatoms in Pliocene sediments of DSDP Hole 86-580 in the Northwest Pacific. https://doi.org/10.1594/PANGAEA.683669
- Barron, JA (1992): (Table 6) Q-mode factor loadings matrix of diatom assemblage from Pliocene sediments of DSDP Hole 86-580 from the Northwest Pacific. https://doi.org/10.1594/PANGAEA.683671
- Barron, JA (1992): (Table 5) Q-mode factor scores matrix of diatom assemblage from Pliocene sediments of DSDP Hole 86-580 from the Northwest Pacific. https://doi.org/10.1594/PANGAEA.683670