Physical properties and sedimentology on core GeoB1510-1

DOI

Detailed information about the sediment properties and microstructure can be provided through the analysis of digital ultrasonic P wave seismograms recorded automatically during full waveform core logging. The physical parameter which predominantly affects the elastic wave propagation in water-saturated sediments is the P wave attenuation coefficient. The related sedimentological parameter is the grain size distribution. A set of high-resolution ultrasonic transmission seismograms (ca. 50-500 kHz), which indicate downcore variations in the grain size by their signal shape and frequency content, are presented. Layers of coarse-grained foraminiferal ooze can be identified by highly attenuated P waves, whereas almost unattenuated waves are recorded in fine-grained areas of nannofossil ooze. Color-encoded pixel graphics of the seismograms and instantaneous frequencies present full waveform images of the lithology and attenuation. A modified spectral difference method is introduced to determine the attenuation coefficient and its power law a = kfn. Applied to synthetic seismograms derived using a "constant Q" model, even low attenuation coefficients can be quantified. A downcore analysis gives an attenuation log which ranges from ca. 700 dB/m at 400 kHz and a power of n = 1-2 in coarse-grained sands to few decibels per meter and n <= 0.5 in fine-grained clays. A least squares fit of a second degree polynomial describes the mutual relationship between the mean grain size and the attenuation coefficient. When it is used to predict the mean grain size, an almost perfect coincidence with the values derived from sedimentological measurements is achieved.

Supplement to: Breitzke, Monika; Grobe, Hannes; Kuhn, Gerhard; Müller, Peter J (1996): Full waveform ultrasonic transmission seismograms: a fast new method for the determination of physical and sedimentological parameters of marine sediment cores. Journal of Geophysical Research: Solid Earth, 101(B10), 22123-22142

Identifier
DOI https://doi.org/10.1594/PANGAEA.735028
Related Identifier https://doi.org/10.1029/96JB01891
Related Identifier https://nbn-resolving.org/urn:nbn:de:gbv:46-ep000102273
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.735028
Provenance
Creator Breitzke, Monika ORCID logo; Grobe, Hannes ORCID logo; Kuhn, Gerhard ORCID logo; Müller, Peter J
Publisher PANGAEA
Publication Year 1996
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (-36.511 LON, 4.723 LAT); Brazil Basin; Rio Grande Rise