Data Report: Late Pliocene-Pleistocene Carbon and Oxygen Stable Isotopes from Benthic Foraminifers at Ocean Drilling Program Site 1123 in the Southwest Pacific

Author(s):  
S.E. Harris
2018 ◽  
Vol 37 (2) ◽  
pp. 445-497 ◽  
Author(s):  
Julian D. Hartman ◽  
Peter K. Bijl ◽  
Francesca Sangiorgi

Abstract. Integrated Ocean Drilling Program (IODP) Expedition 318 recovered a  ∼ 170 m long Holocene organic-rich sedimentary sequence at Site U1357. Located within the narrow but deep Adélie Basin close to the Antarctic margin, the site accumulated sediments at exceptionally high sedimentation rates, which resulted in extraordinary preservation of the organic sedimentary component. Here, we present an overview of 74 different mainly marine microfossil taxa and/or types found within the organic component of the sediment, which include the remains of unicellular and higher organisms from three eukaryotic kingdoms (Chromista, Plantae, and Animalia). These remains include phytoplanktonic (phototrophic dinoflagellates and prasinophytes) and very diverse zooplanktonic (heterotrophic dinoflagellates, tintinnids, copepods) organisms. We illustrate each marine microfossil taxon or type identified by providing morphological details and photographic images, which will help with their identification in future studies. We also review their ecological preferences to aid future (palaeo)ecological and (palaeo)environmental studies. The planktonic assemblage shows a high degree of endemism related to the strong influence of the sea-ice system over Site U1357. In addition, we found the remains of various species of detritus feeders and bottom-dwelling scavengers (benthic foraminifers and annelid worms) indicative of high export productivity at Site U1357. This study shows the potential of organic microfossil remains for reconstructing past environmental conditions, such as sea-ice cover and (export) productivity.


2012 ◽  
Vol 8 (1) ◽  
pp. 79-87 ◽  
Author(s):  
N. Khélifi ◽  
M. Sarnthein ◽  
B. D. A. Naafs

Abstract. Ocean Drilling Program (ODP) Site 982 provided a key sediment section at Rockall Plateau for reconstructing northeast Atlantic paleoceanography and monitoring benthic δ18O stratigraphy over the late Pliocene to Quaternary onset of major Northern Hemisphere glaciation. A renewed hole-specific inspection of magnetostratigraphic reversals and the addition of epibenthic δ18O records for short Pliocene sections in holes 982A, B, and C, crossing core breaks in the δ18O record published for Hole 982B, now imply a major revision of composite core depths. After tuning to the orbitally tuned reference record LR04, the new composite δ18O record results in a hiatus, where the Kaena magnetic subchron might have been lost, and in a significant age reduction for all proxy records by 130 to 20 ky over the time span 3.2–2.7 million years ago (Ma). Our study demonstrates the general significance of reliable composite-depth scales and δ18O stratigraphies in ODP sediment records for generating ocean-wide correlations in paleoceanography. The new concept of age control makes the late Pliocene trends in SST (sea surface temperature) and atmospheric pCO2 at Site 982 more consistent with various paleoclimate trends published from elsewhere in the North Atlantic.


1995 ◽  
Vol 10 (4) ◽  
pp. 841-865 ◽  
Author(s):  
Timothy J. Bralower ◽  
James C. Zachos ◽  
Ellen Thomas ◽  
Matthew Parrow ◽  
Charles K. Paull ◽  
...  

2011 ◽  
Vol 7 (3) ◽  
pp. 1631-1646
Author(s):  
N. Khélifi ◽  
M. Sarnthein ◽  
B. D. A. Naafs

Abstract. Ocean Drilling Program (ODP) Site 982 provided a key sediment section at Rockall Plateau for reconstructing northeast Atlantic paleoceanography and monitoring benthic δ18O stratigraphy over the Late Pliocene to Quaternary onset of major Northern Hemisphere Glaciation. A renewed hole-specific inspection of magnetostratigraphic events and the addition of epibenthic δ18O records for short Pliocene sections in holes 982A, B, and C, crossing core breaks in the δ18O record published for Hole 982B, now imply a major revision of composite core depths. After tuning to the orbitally tuned reference record LR04 the new composite δ18O record results in a hiatus, where the Kaena magnetic event might been lost, and in a significant age reduction for all proxy records by 130 to 20 ka over the time span 3.2–2.7 million yr ago (Ma). Our study demonstrates the significance of reliable composite-depth scales and δ18O stratigraphies in ODP sediment records for ocean-wide correlations in paleoceanography and makes Late Pliocene trends found at Site 982 much better comparable to those published from elsewhere in the North Atlantic.


2018 ◽  
Vol 48 (4) ◽  
pp. 288-300 ◽  
Author(s):  
Martin P. Crundwell

Abstract Studies of topotypes of Truncorotalia crassaconica from the East Coast Basin of New Zealand and populations of Tr. crassaconica at Ocean Drilling Program Site 1123 and Deep Sea Drilling Project Site 284 in the southwest Pacific revealed two morphospecies. One of these is a late Pliocene species, Truncorotalia crassaconica s.s., that has low, slit-like apertures with thin, smooth apertural lips. The other is Globoconella pseudospinosa n. sp., an early Pliocene form with arched apertures and pustulose apertural lips. The short stratigraphic ranges of both species are potentially useful as biostratigraphic markers for the subdivision of Plio-Pleistocene stages in New Zealand and the temperate southwest Pacific. Populations of Gc. pseudospinosa, with mostly sinistrally coiled specimens, occur throughout the lectostratotype of the New Zealand Opoitian Stage at Mangapoike River in the East Coast Basin and are confined to the early Pliocene (Opoitian) at sites 1123 and 284, between 4.57 and 4.10 Ma. Small populations of Tr. crassaconica s.s., with mostly dextrally coiled specimens, occur in the late Pliocene (Waipipian Stage) between 3.53 and 2.98 Ma. Sporadic occurrences of relatively rare, mostly sinistrally coiled specimens of Tr. aff. crassaconica occur earlier at sites 1123 and 284 in the late Miocene to Pliocene between ca. 5.5 and 3.53 Ma. These specimens are distinguished in having open umbilici and almost straight umbilical sutures, similar to the late Miocene specimens of Truncorotalia crassaformis.


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