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(Table 1) Strontium isotope ratios for ichtyolith samples and age model of ODP Site 145-886
No full textSr-analyses by C.E. Jones see Snoeckx et al. (1995) dataset: doi:10.1594/PANGAEA.712111, data are here normalized to the NBS standard (0.710276
(Table 2) Rb and Sr concentrations and 87Rb/86Sr ratios of ODP sites 145-885 and 145-886
No full text(Table 2) Rb and Sr concentrations and 87Rb/86Sr ratios of ODP sites 145-885 and 145-88
(Table 1) Strontium isotope ratios for ichtyolith samples and age model of ODP Hole 145-885A
No full text(Table 1) Strontium isotope ratios for ichtyolith samples and age model of ODP Hole 145-885
Strontium isotope ratios of fish teeth from ODP sites in the central North Pacific
No full textStrontium isotopic compositions of ichthyoliths (microscopic fish remains) in deep-sea clays recovered from the North Pacific Ocean (ODP holes 885A, 886B, and 886C) are used to provide stratigraphic age control within these otherwise undatable sediments. Age control within the deep-sea clays is crucial for determining changes in sedimentation rates, and for calculating fluxes of chemical and mineral components to the sediments.
The Sr isotopic ages are in excellent agreement with independent age datums from above (diatom ooze), below (basalt basement) and within (Cretaceous-Tertiary boundary) the clay deposit. The 87Sr/86Sr ratios of fish teeth from the top of the pelagic clay unit (0.7089891), indicate an Late Miocene age (5.8 Ma), as do radiolarian and diatom biostratigraphic ages in the overlying diatom ooze. The 87Sr/86Sr ratio (0.707887) is consistent with a Cretaceous-Tertiary boundary age, as identified by anomalously high iridium, shocked quartz, and sperules in Hole 886C. The 87Sr/86Sr ratios of pretreated fish teeth from the base of the clay unit are similar to Late Cretaceous seawater (0.707779-0.7075191), consistent with radiometric ages from the underlying basalt of 81 Ma. Calculation of sedimentation rates based on Sr isotopic ages from Hole 886C indicate an average sedimentation rate of 17.7 m/Myr in Unit II (diatom ooze), 0.55 m/Myr in Unit IIIa (pelagic clay), and 0.68 m/Myr in Unit IIIb (distal hydrothermal precipitates). The Sr isotopic ages indicate a period of greatly reduced sedimentation (or possible hiatus) between about 35 and 65 Ma (Eocene-Paleocene), with a linear sedimentation rate of only 0.04 m/Myr The calculated sedimentation rates are generally inversely proportional to cobalt accumulation rates and ichthyolith abundances. However, discrepancies between Sr isotope ages and cobalt accumulation ages of l0-15 Myr are evident, particularly in the middle of the clay unit IIIa (Oligocene-Paleocene)
(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP holes 62-465A and 17-167
No full text(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP holes 62-465A and 17-16
(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP Hole 73-522
No full textAges were assigned on the basis of paleomagnetic reversal stratigraphy (Poore et al., 1982, doi:10.1130/0091-7613(1982)102.0.CO;2) and the time scale recommanded by Ness et al. (1980, doi:10.1029/RG018i004p00753
(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP Hole 48-400A
No full text(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP Hole 48-400
(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP Hole 90-590B
No full text(Table 3) Rubidium and strontium concentrations and isotope ratios of DSDP Hole 90-590
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