Data Report: Geochemical Well Logs through Cenozoic and Quaternary Sediments from Sites 815, 817, 820, 822, and 823

Abstract

Geochemical well logs were obtained through sediments at Sites 815, 817, 820, 822, and 823 of Leg 133. Corrections have been applied to the logs to account for variations in hole size, drilling-fluid composition, and drill-pipe attenuation. Oxide and calcium carbonate weight percentages have been calculated from the processed logs and are compared with the available carbonate measurements from core. Log-derived CaCO 3 measurements correlate well with shipboard CaCO 3 core-derived measurements in each of the logged open-hole intervals.

Explanatory Notes

“…A rough estimate of Mg + Na can be made in some instances by using the photoelectric factor (PEF), measured by the lithodensity tool (Hertzog et al, 1989). This calculation was not implemented on the geochemical data from Hole 89IC as the GST and PEF data in combination were of insufficient quality; the results of the Mg + Na calculation have been found to erroneous in many ODP logging environments (Bristow et al, 1992;Pratson et al, 1993).…”

Data Report: Geochemical Logging Results from the Lau Basin and Tonga Ridge: Sites 834, 838, 839, and 840

“…Further explanation of this technique is found in Hertzog et al (1989). This calculation was not attempted in this leg; the results of the Mg calculation have been found to be erroneous in ODP holes (Pratson et al, 1993). The inclusion of this unreliable Mg + Na curve in the normalization with the other elements would have induced noise into all the other elements.…”

Explanatory notes

“…936A as the (Mg+ Na) calculation has proven to be erroneous in ODP logging conditions and only adds noise to the other elements when included (Pratson et al, 1993).…”