|
Component
|
Conical
|
Torishima Forearc
|
South Chamorro
|
Seawater
|
|
|---|---|---|---|---|---|
| ODP site: | 780 | 783 | 784 | 1200 |
|
| Location: | 19°32.5´N, 146°39.2´E | 30°57.86´N,141°47.27´E | 54.49´N,44.27´E | 13°47.0´N,146°0.2´E |
|
| Deepest sample (mbsf): | 130 | 400 | 71 |
|
|
| Cations/anions (mmol/kg): | |||||
| Chloride | 260 ± 25 | 550 ± 5 | 510 ± 5 | 542 | |
| Sulfate | 46 ± 1 | 9 ± 3 | 28 ± 1 | 28 | |
| Alkalinity | 52 ± 13 | 1.3 ± 0.4 | 62 ± 8 | 2.3 | |
| Carbonate alkalinity (meq/kg) | 35 ± 15 | 1.1 ± 0.4 | 45 ± 7* | 1.9 | |
| pH at 25°C | 12.5 ± 0.1 | 9.6 ± 0.4 | 12.5 ± 0.1 | 8.1 | |
| Na | 390 ± 10 | 460 ± 20 | 610 ± 10 | 466 | |
| Na/Cl (molar) | 1.5 ± 0.1 | 0.84 ± 0.02 | 1.2 ± 0.02 | 0.86 | |
| K | 15 ± 1 | 5 ± 1 | 19 ± 1 | 10.1 | |
| Mg | 0.003 ± 0.002 | 1 ± 1 | <0.01 | 52.4 | |
| Ca | 1 ± 0.5 | 55 ± 5 | 0.3 ± 0.1 | 10.2 | |
|
|
|||||
| Charge balance (calc.) | 3.0 ± 25 | 7.7 ± 20 | 1.6 ± 10 | 0.9 | |
|
|
|||||
| Trace components (µmol/kg): | |||||
| CH4 | 2000 ± 1000 | 2 ± 1 | 2000 ± 1000* | 0.0004 | |
| Li | 1.6 ± 0.5 | 16 ± 5 | 0.4 ± 0.1 | 26 | |
| Rb | 7.8 ± 0.6 | 1 ± 0.2 | 10 ± 2 | 1.37 | |
| Sr | 20 ± 10 | 200 ± 50 | 10 ± 2 | 90 | |
| Ba | 0.1 ± 0.05 | 1.6 ± 0.7 | 0.4? | 0.14 | |
| B | 3900 ± 100 | 180 ± 80 | 3200 ± 200 | 410 | |
| Si | 60 ± 30 | 10 ± 8 | 70 ± 20 | 190 | |
| F | NA | NA | 47 ± 3 | 67 | |
| Mn | <0.01 | 0.4 ± 0.2 | 0.01 | 0 | |
| Fe | 2 ± 1 | 1 ± 0.9 | 2 ± 0.5 | 0 | |
| Phosphate | 0.4 ± 0.3 | NA | 0.2 | 2.8 | |
| NH3 | 265 ± 5 | 140 ± 20 | 220 ± 10 | 0 | |
| Reduced sulfur (total) | <250 | 0 | <250 | 0 | |
|
|
|||||
| C2H6 | 7 | 0 | 2 | 0 | |
| C1/C2 | 290 ± 15 |
|
780 ± 10 |
|
|
| 87Sr/86Sr | <0.7062 | <0.7070 | 0.70535 ± 0.0001 | 0.7091 | |
 34SO4 ( CDT) |
13.7 ± 0.3 | 31.2 ± 0.4 | NA | 20.5 | |
|
18O ( SMOW) |
4.0 ± 0.6 | –0.4 ± 0.2 | 2.5 ± 0.5 | 0 | |
|
D ( SMOW) |
3 ± 2 | –2 ± 2 | 12 ± 2 | 0 | |
Notes: Table after Mottl et al. (2003). Conical and South Chamorro Seamounts represent asymptotic composition of deep upwelling fluid from an active mud volcano. Conical Seamount data are from Mottl (1992), Mottl and Alt (1992), Haggerty and Chaudhuri (1992), and Benton (1997). Torishima Forearc Seamount represents a product of harzburgite-seawater reaction within an inactive mud volcano in the Izu-Bonin forearc (Mottl, 1992). Seawater composition is estimated from local bottom water. Carbonate alkalinity calculated using the PHREEQC program (Parkhurst and Appelo, 1999). CDT = Canyon Diablo troilite, SMOW = Standard Mean Ocean Water. * = 13CH4 = –11 ± 5 Vienna Peedee belemnite (VPDB) and 13C-DIC = –18 ± 3 VPDB at 15 mbsf.