Proc. IODP, 320/321, Data report: calibration of XRF-estimated CaCO3 along the Site U1338 splice

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Chapter contents Abstract Introduction Methods XRF data acquisition CaCO₃ analyses Calibration of XRF data to CaCO₃ measurements Discussion: high-resolution CaCO₃ profile from Site U1338 Is the high-resolution XRF CaCO₃ estimate signal or noise? Large-scale features of the Site U1338 CaCO₃ profile Conclusions Acknowledgments References Figures F1. Site U1338 maps. F2. Raw XRF Ca peak area profile. F3. NMS XRF CaCO₃. F4. Site U1338 carbonate profile. F5. Measured vs. XRF-estimated CaCO₃. F6. Bias in XRF estimate of CaCO₃. F7. XRF CaCO₃ profile. F8. Low CaCO₃ transients. Tables T1. Discrete CaCO₃ analyses. T2. XRF-estimated CaCO₃ wt%. PDF file			Previous \| Next doi:10.2204/iodp.proc.320321.205.2013 Conclusions We used XRF measurement of Ca peak area and discrete CaCO₃ analyses from Site U1338 to calibrate a high-resolution CaCO₃ profile along the Site U1338 splice. Data spacing of 2.5 cm results in analyses at ~2 k.y. age spacing from 0 to 58 cmcd (0 to 4.65 Ma) and ~ 1 k.y. spacing or less below, from 4.65 to >16 Ma. By comparing discrete data, XRF data, and the GRA bulk density profile, we find that the high-resolution XRF profile represents changes in sedimentary CaCO₃ content and not measurement variability. We find that the XRF CaCO₃ estimate is typically within 5% of the discrete measurements, but that there is a minor depth-related bias to the XRF CaCO₃ estimate. This new high-resolution CaCO₃ profile will allow further work to probe the changes in the Neogene carbon cycle. Top of page \| Previous \| Next

Conclusions