Brückmann, Warner; Moran, Kate; Taylor, Elliott (1993): (Table 1) Error analysis definitions for Unit IVb sediments above décollement in ODP Hole 131-808C [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.785238, Supplement to: Brückmann, W et al. (1993): Acoustic anisotropy and microfabric development in accreted sediment from the Nankai Trough. In: Hill, IA; Taira, A; Firth, JV; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 131, 221-233, https://doi.org/10.2973/odp.proc.sr.131.121.1993
Always quote citation above when using data! You can download the citation in several formats below.
Published: 1993 (exact date unknown) • DOI registered: 2012-07-26
Abstract:
Complete penetration of frontal thrust and décollement of the Nankai Trough accretionary complex in Site 808 during ODP Leg 131 provided a wealth of structural observations and physical property data. In this paper possible mechanisms are discussed that could be responsible for the development of irregular downhole trends in acoustic anisotropy observed in Site 808. After various steps of data reduction and screening, a paleomagnetic reorientation procedure is applied to a selected group of physical property data sets. This facilitates the integration of the observed changes in physical properties with the geotectonic framework at the deformation front of the Nankai Trough accretionary complex. The paleomagnetic database was employed in the reconstruction of directional properties of acoustic velocities of the Lower Shikoku Basin sedimentary sequence, which is divided by a sharply defined décollement into an accreting and a subducting portion.
P-wave velocity anisotropies derived from paleomagnetically oriented samples in the upper part of this 420-m-thick hemipelagic sequence show maximum values in the direction parallel and normal to the inferred vector of plate convergence (310°-315°). No preferred orientation of P-wave velocity anisotropy is found in the subducting part of the sequence.
The preferred direction of maximum anisotropy parallel to the convergence vector is also in accordance with the true direction of the observed macro- to mesoscale structural features in Site 808. Microfractures and microcracks forming as stress relief and tensile fractures in cores of semilithified sediment normal and perpendicular to the maximum horizontal stress are discussed as control mechanisms for the development of the observed anisotropy pattern.
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Latitude: 32.352800 * Longitude: 134.944300
Date/Time Start: 1990-04-16T04:00:00 * Date/Time End: 1990-05-02T14:40:00
Minimum DEPTH, sediment/rock: 823.4 m * Maximum DEPTH, sediment/rock: 936.0 m
Event(s):
131-808C * Latitude: 32.352800 * Longitude: 134.944300 * Date/Time Start: 1990-04-16T04:00:00 * Date/Time End: 1990-05-02T14:40:00 * Elevation: -4686.0 m * Penetration: 1327 m * Recovery: 572.43 m * Location: Philippine Sea * Campaign: Leg131 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 108 cores; 1028.5 m cored; 0 m drilled; 55.7 % recovery
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Sample code/label | Sample label | Brückmann, Warner | DSDP/ODP/IODP sample designation | ||
| 2 | DEPTH, sediment/rock | Depth sed | m | Geocode – mbsf | ||
| 3 | Velocity, compressional wave anisotropy | Vp anisotropy | % | Brückmann, Warner | p-wave velocity normal to core axis (transverse) | |
| 4 | Velocity, compressional wave anisotropy | Vp anisotropy | % | Brückmann, Warner | p-wave velocity parallel to core axis (longitudinal) | |
| 5 | Acoustic anisotropy | Acoust aniso | % | Brückmann, Warner | ||
| 6 | Error, absolute | Error a | ± | Brückmann, Warner | Taylor error | |
| 7 | Error, relative | Error r | % | Brückmann, Warner | Taylor error/acoustic anisotropy | |
| 8 | Difference | Diff | Brückmann, Warner | Anisotropy - Taylor error | ||
| 9 | Difference | Diff | Brückmann, Warner | Anisotropy + Taylor error | ||
| 10 | Error, absolute | Error a | ± | Brückmann, Warner | Gauss error | |
| 11 | Error, relative | Error r | % | Brückmann, Warner | Gauss error/acoustic anisotropy | |
| 12 | Difference | Diff | Brückmann, Warner | Anisotropy - Gauss error | ||
| 13 | Difference | Diff | Brückmann, Warner | Anisotropy + Gauss error |
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
1020 data points