Publication Date:
2024-01-09
Description:
An integrated chemostratigraphic (87Sr/86Sr, d13C and 18O) study of benthic foraminifera is presented for a 210 m-thick, intermediate depth (upper/middle bathyal transition), Miocene nannofossil ooze section of Ocean Drilling Program Site 1120, Campbell Plateau off New Zealand. Our results indicate that new 87Sr/86Sr, d13C and d18O profiles are wholly consistent with their respective Miocene reference curves. These observations facilitate identification of a total of five reliable chemostratigraphic datums, which are based on the fundamental structural changes in the 87Sr/86Sr curve and paired simultaneous d13C and d18O events. The resultant age-depth relationship clearly shows that the Miocene (20-5 Ma) biopelagic sedimentation on the Campbell Plateau was essentially continuous at a moderate to high, linear sedimentation rate (17.5 m/m.y. with an exception of the uppermost 13 m). Our findings do not support the shipboard biostratigraphic age model, which assumes that the critical early-middle Miocene transition was interrupted by a major hiatus (〈~3 m.y.). Because of its unique bathymetric setting at a paleowater-depth of ~ 600 m, which is among the shallowest of the coeval isotopically studied deep-sea sections in the South Pacific/Southern Ocean, Site 1120 will serve as a reference section for surveying the evolution of intermediate-water paleoceanography in the Southern Hemisphere across the middle Miocene climatic transition.
Keywords:
181-1120B; 181-1120D; Calcium carbonate; Cibicidoides spp., δ13C; Cibicidoides spp., δ18O; Comment; DEPTH, sediment/rock; DRILL; Drilling/drill rig; Event label; Finnigan TRITON thermal ionization mass spectrometer (TIMS); Joides Resolution; Leg181; Mass spectrometer Finnigan MAT 251; Ocean Drilling Program; ODP; Period; Sample code/label; South Pacific Ocean; Strontium-87/Strontium-86 ratio; Strontium-87/Strontium-86 ratio, error
Type:
Dataset
Format:
text/tab-separated-values, 501 data points
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