Nobes, David C; Murray, Richard W; Kuramoto, Shinichi; Pisciotto, Kenneth A; Holler, Peter (1992): Silica diagenesis of ODP Sites 127-795 and 127-797 [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.777262, Supplement to: Nobes, DC et al. (1992): Impact of silica diagenesis on physical property variations. In: Pisciotto, KA; Ingle, JCJr.; von Breymann, MT; Barron, J; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 127/128(1), 3-31, https://doi.org/10.2973/odp.proc.sr.127128-1.111.1992
Always quote citation above when using data! You can download the citation in several formats below.
Abstract:
The silica diagenetic boundaries, especially the transition from opal-A to opal-CT, are significant seismic and thermal horizons in the Japan Sea. Diagenesis has a marked effect on laboratory and downhole logging physical properties. Index property residues were used for X-ray diffraction and scanning electron microscopy studies that complement the physical property and logging data so that we may examine the diagenetic transitions in some detail. We identify the sharpest physical property gradients with the opal-A/opal-CT boundaries for each site; in a number of cases, the boundaries are different from those previously defined. The changes in the physical properties, especially the acoustic velocity, are distinct across the opal-A/opal-CT boundary. The thickness of the opal-A to opal-CT transition zone depends on the way in which the zone is defined. If we interpret the diagenetic transition zone to be between the point where a clear-cut change or trend starts, to the point where the changes are indistinguishable from the natural background variability, then the zone can be 10 m or more thick. The profiles of the various physical properties are often parallel, and begin to change well above the diagenetic boundary. This is consistent with the shallow occurrence of opal-CT. The opal-CT to quartz transformation, in contrast, is rapid, and the transition zone is at most 1 m thick. The physical property changes are not as distinct across the opal-CT/quartz boundary.
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Median Latitude: 41.301500 * Median Longitude: 136.750800 * South-bound Latitude: 38.616000 * West-bound Longitude: 134.536000 * North-bound Latitude: 43.987000 * East-bound Longitude: 138.967000
Date/Time Start: 1989-07-12T20:15:00 * Date/Time End: 1989-08-04T17:00:00
Event(s):
127-795A * Latitude: 43.987000 * Longitude: 138.967000 * Date/Time Start: 1989-07-12T20:15:00 * Date/Time End: 1989-07-16T00:00:00 * Elevation: -3311.0 m * Penetration: 365.9 m * Recovery: 258.26 m * Location: Japan Sea * Campaign: Leg127 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 39 cores; 364.9 m cored; 0 m drilled; 70.8 % recovery
127-795B * Latitude: 43.987000 * Longitude: 138.965000 * Date/Time Start: 1989-07-16T00:00:00 * Date/Time End: 1989-07-22T02:45:00 * Elevation: -3310.0 m * Penetration: 762.2 m * Recovery: 188.94 m * Location: Japan Sea * Campaign: Leg127 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 41 core; 397 m cored; 0 m drilled; 47.6 % recovery
127-797B * Latitude: 38.616000 * Longitude: 134.536000 * Date/Time Start: 1989-07-31T20:00:00 * Date/Time End: 1989-08-04T17:00:00 * Elevation: -2874.0 m * Penetration: 495.7 m * Recovery: 370.69 m * Location: Japan Sea * Campaign: Leg127 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 53 cores; 495.7 m cored; 0 m drilled; 74.8 % recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
2 datasets
Download Data
Datasets listed in this publication series
- Nobes, DC; Murray, RW; Kuramoto, S et al. (1992): (Table 1) Mineralogy of ODP Site 127-795. https://doi.org/10.1594/PANGAEA.777259
- Nobes, DC; Murray, RW; Kuramoto, S et al. (1992): (Table 2) Mineralogy of ODP Hole 127-797B. https://doi.org/10.1594/PANGAEA.777260