Milankovitch frequency peaks of ODP Site 113-693 (Table 3) ...
The first well logs collected below the Antarctic circle were obtained during Leg 113 at Site 693 on the Dronning Maud Land Margin (Antarctica) in the Weddell Sea. Gamma-ray, resistivity, and sonic logs were collected between 108.0 and 439.0 mbsf. The downhole logs show good agreement with the data...
Main Authors: | , , |
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Format: | Dataset |
Language: | English |
Published: |
PANGAEA
1990
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Subjects: | |
Online Access: | https://dx.doi.org/10.1594/pangaea.754301 https://doi.pangaea.de/10.1594/PANGAEA.754301 |
Summary: | The first well logs collected below the Antarctic circle were obtained during Leg 113 at Site 693 on the Dronning Maud Land Margin (Antarctica) in the Weddell Sea. Gamma-ray, resistivity, and sonic logs were collected between 108.0 and 439.0 mbsf. The downhole logs show good agreement with the data collected from cores and provide a continuous measurement of the sedimentary record. These continuous log records show that the rather uniform Tertiary lithology seen in cores is characterized by high-frequency variability in the log data. Several thin hard streaks are identified, the largest of which coincides with a major Miocene hiatus. Associated with this hiatus is a change to lower illite content (and correspondingly lower gamma-ray counts) and to a significant increase in diatom content.Spectral analysis of the logs was performed on the lower Pliocene through upper Oligocene interval (108.0-343.0 mbsf). Between 108.0 and 245.0 mbsf, average sedimentation rates (50 and 26 m/m.y.) are high enough to show that ... : Quality of interval frequency is determined by the presence or absence of the top or near top of an amplitude peak within ± 0.5 m.y. of the predicted frequency. Correlation: G = good, M = moderate, P = poor. ... |
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