Physical properties of sediment core CRP-3 ...

• Main Author: Bücker, Christian J
• Format: Dataset
• Language: English
• Published: PANGAEA 2001
• Subjects: DEPTH, sediment/rock; Spectroscopy gamma ray; Potassium; Uranium; Thorium; Susceptibility; Z-anomaly of magnetic field; Resistivity, shallow; Resistivity, deep; Density, wet bulk; Porosity; Velocity, compressional wave; Thorium/Potassium ratio; Factor 1; Factor 2; Factor 3; Core wireline system; Downhole logging; Calculated; Multivariate statistical analysis; CRP-3; Sampling/drilling from ice; Cape Roberts Project CRP; Antarc*; Antarctica; McMurdo Sound; Ross Sea; Victoria Land
• Online Access: https://dx.doi.org/10.1594/pangaea.57345; https://doi.pangaea.de/10.1594/PANGAEA.57345

Drillhole CRP-3 in northern McMurdo Sound (Ross Sea, Antarctica) targeted the western margin of the Victoria Land basin to investigate Neogene to Palaeogene climate and tectonic history by obtaining continuous core and downhole logs. Well logging of CRP-3 has provided a complete and comprehensive data set of in situ geophysical measurements down to nearly the bottom of the hole (920 m below sea floor (mbsf)).This paper describes the evaluation and interpretation of the downhole logging data using the multivariate statistical methods of factor and cluster analysis. The factor logs mirror the basic geological controls (i.e., grain size, porosity, clay mineralogy) behind the measured geophysical properties, thereby making them easier to interpret geologically. Cluster analysis of the logs delineates individual logging or sedimentological units with similar downhole geophysical properties. These objectively and independently defined units help differentiate lithological and sedimentological characteristics (e.g. ... : P-wave Velocity and Core Diameter: Sensor orientation - vertical, Transducer - Acoustic Rolling Contact Transducer (DEOTEK Ltd.), Transmitter pulse frequencey - 230 kHz, Transmitted pulse repitition rate: 100 Hz, Received pulse resolution - 50 ns, P-wave travel-time offset - 18.8 µs (HQ) and 19.8 µs (NQ).P-wave Transmission Seismograms: ADC board - T3012 (National Instruments). Sampling frequency and resolution - 30 Mhz, 12 bit, Sampling interval - 50 ns, Length of seismograms - 200 msWet Bulk Density: Sensor orientation - vertical, Gamma ray source - Cs-137, Source activity - 356 MBq, Source energy - 0.662 MeV, Counting time - 10 s, Collimator diameter - 5 mm (whole cores HQ/NQ), 2.5 mm (half cores HQ), Gamma detector - NaI-Scintillation Counter (John Count Scientific Ltd.)Magnetic susceptibility: Loop sensor type - MS-2B (Bartington Ltd.), Loop sensor diameter - 80 mm, Loop sensor coil diameter - 88 mm, Alternating field frequency 0.565 kHz, Sensitivity - 1s, 10s (HQ), 10s (NQ), Magnetic field intensity - ...