Wu, Jiawang; Liu, Zhifei; Yu, Xun (2022): Strontium and Nd isotope compositions of hydrothermally altered basaltic rocks in IODP Hole 368-U1502B (Dataset S4) [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.946143, In: Wu, J et al. (2022): Geochemistry of IODP Hole U1502B at the South China Sea rifted margin [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.946146
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Published: 2022-07-08 • DOI registered: 2022-08-30
Keyword(s):
Related to:
Wu, Jiawang; Liu, Zhifei; Yu, Xun (2021): Plagioclase-regulated hydrothermal alteration of basaltic rocks with implications for the South China Sea rifting. Chemical Geology, 585, 120569, https://doi.org/10.1016/j.chemgeo.2021.120569
Funding:
Shanghai Association for Science and Technology (SAST), grant/award no. 20590780200: Shanghai Science and Technology Innovation Action Plan
Coverage:
Latitude: 18.464663 * Longitude: 116.230682
Date/Time Start: 2017-04-29T19:30:00 * Date/Time End: 2017-05-13T20:50:00
Minimum DEPTH, sediment/rock: 733.75 m * Maximum DEPTH, sediment/rock: 917.41 m
Event(s):
368-U1502B * Latitude: 18.464663 * Longitude: 116.230682 * Date/Time Start: 2017-04-29T19:30:00 * Date/Time End: 2017-05-13T20:50:00 * Elevation: -3763.6 m * Campaign: Exp368 * Basis: Joides Resolution * Method/Device: Core drilling (CDRILL) * Comment: Drill in casing to 723.7 mbsf
Comment:
a Six sample-types are distinguished (see Section 4); note that the fully altered samples and the breccia sample are taken as endmembers of the hydrothermal alteration and associated brecciation, respectively.
b Normalized to the NBS-SRM 987 value of 87Sr/86Sr = 0.710248 (Thirlwall, 1991), with 2SE internal errors in brackets; the 2SD external errors are <18 ppm; the 2σ uncertainties in 87Sr/86Sr from BHVO-2 and AGV-2 standards are 0.703467 ± 0.000010 (n=2) and 0.703959 ± 0.000015 (n=3), respectively.
c Normalized to the JNdi-1 value of 143Nd/144Nd = 0.512115 (Tanaka et al., 2000), with 2SE internal errors in brackets; εNd = [(143Nd/144Nd) measured / (143Nd/144Nd) CHUR – 1] × 104, while CHUR is 0.512638 (Jacobson and Wasserburg, 1980); the 2SD external errors are <19 ppm (i.e. <0.4 εNd-unit); the 2σ uncertainties in 143Nd/144Nd from BHVO-2 and AGV-2 standards are 0.512997 ± 0.000028 (n=2) and 0.512802 ± 0.000038 (n=3), respectively.
d Degree of alteration in natural hydrothermal system can be estimated (cf. Kawahata et al., 2001; Delacour et al., 2008): Sr isotope exchange = (εSrfrock – εSrirock) / (εSriwater – εSrirock), where the subscripts (water) and (rock) refer to the hydrothermal fluid and altered rock, respectively; and the superscripts (i) and (f) identify the initial and final values of Sr isotope ratios, respectively.
e Assuming the final equilibrium of Sr isotope, the water–rock interaction can be quantified by simple mass balance equations, respectively, for closed system (cf. Berndt et al., 1988; Kawahata et al., 2001) and for open system (cf. Albarède, 1995; Delacour et al., 2008); W/R ratio (close system) = (εSrirock – εSrfrock) / (εSrfrock – εSriwater) * (Srrock / Srwater); W/R ratio (open system) = ln [(εSrirock – εSrfrock) / (εSrfrock – εSriwater) +1] * (Srrock / Srwater); where W is the mass of hydrothermal fluid, R is the mass of rock being altered; εSrirock and εSrfrock is the initial and final isotopic ratio of rock, respectively; εSriwater and εSrfwater is the initial (i.e. seawater) and final isotopic ratio of fluid, respectively; note that εSrfrock is equal to εSrfwater; Srrock and Srwater is the Sr concentration of unaltered rock and of seawater, respectively. The values of εSrirock (87Sr/86Sr: 0.70309) and Srrock (Sr: 168 ppm) after the mean values of Site U1500 basalts (Yu and Liu, 2020) and SCS seafloor basalts (i.e. Sites U1431, U1433, and U1434; Zhang et al., 2018), and the values of εSrfwater (87Sr/86Sr: 0.70780; McArthur et al., 2012) and Srwater (Sr: 12 ppm; Antonelli et al., 2017) after the global seawater estimates of the late-Eocene age.
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Sample code/label | Sample label | Wu, Jiawang | |||
| 2 | DEPTH, sediment/rock | Depth sed | m | Wu, Jiawang | Geocode – mbsf | |
| 3 | Sample type | Samp type | Wu, Jiawang | |||
| 4 | Strontium | Sr | mg/kg | Wu, Jiawang | given in ppm | |
| 5 | Neodymium | Nd | mg/kg | Wu, Jiawang | given in ppm | |
| 6 | Strontium-87/Strontium-86 ratio | 87Sr/86Sr | Wu, Jiawang | b | ||
| 7 | Strontium-87/Strontium-86 ratio, standard deviation | 87Sr/86Sr std dev | ± | Wu, Jiawang | 2σ, b | |
| 8 | Neodymium-143/Neodymium-144 ratio | 143Nd/144Nd | Wu, Jiawang | |||
| 9 | Neodymium-143/Neodymium-144 ratio, standard deviation | 143Nd/144Nd std dev | ± | Wu, Jiawang | 2σ, c | |
| 10 | ε-Neodymium | ε-Nd | Wu, Jiawang | c | ||
| 11 | ε-Neodymium, standard deviation | ε-Nd std dev | ± | Wu, Jiawang | ||
| 12 | Strontium isotope exchange | Sr ex | % | Wu, Jiawang | d | |
| 13 | Water/rock ratio | W/R ratio | Wu, Jiawang | closed, e | ||
| 14 | Water/rock ratio | W/R ratio | Wu, Jiawang | open, e |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
401 data points