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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
1983
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| Accesso online: | https://doi.org/10.1594/PANGAEA.816535 |
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| _version_ | 1867169083259092992 |
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| author | Hubberten, Hans-Wolfgang |
| author_facet | Hubberten, Hans-Wolfgang |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | About 150 basalt samples from Hole 504B, near the Costa Rica Rift were analyzed for sulfur content and sulfur-isotope composition. The basement in Hole 504B can be divided into an upper part, which has oxidative alteration (274.5-550 m below sea floor), and a lower part, which has nonoxidative alteration (550-835 m below sea floor) (the interval from 540 to 585 meters actually is transitional). This division is reflected in both the sulfur content and the sulfurisotope composition. Oxidative alteration of basalts by sea water at low temperatures has resulted in a depletion in sulfur in the upper part of the hole (mostly less than 600 ppm S) as compared to fresh sulfur-saturated oceanic tholeiites (900-1200 ppm S). High amounts of sulfur in the lower part of the hole are a result of precipitation of secondary pyrite under non-oxidative or weakly oxidative conditions from solutions which dissolved igneous sulfides. The average sulfur-isotope composition of the primary igneous sulfides is d34S = -0.01 per mil, which is close to the assumed mantle sulfur composition (d34S = 0 per mil. Pyrite and sulfate sulfur extracted together in a separate preparation step (as "pyrite-sulfate" sulfur) indicate addition of sea-water sulfate to the upper part of the basalts. The d34S of secondary pyrite isolated by hand-picking varies between -8.0 and +5.8 per mil; the "pyrite-sulfate" sulfur (d34S = -4.8 to +10.5 per mil), as well as that of the isolated pyrite, may have originated in the precipitation of pyrite from solutions containing sulfur from the dissolution of igneous sulfides, but addition of sulfur transported by hydrothermal solutions cannot be excluded. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_816535 |
| institution | PANGAEA |
| language | en |
| publishDate | 1983 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 1) Sulfur isotopes, total sulfur, and degree of oxidation of basalt samples from DSDP Hole 69-504B and 70-504B Hubberten, Hans-Wolfgang 69-504B; 70-504B; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Event label; Glomar Challenger; Leg69; Leg70; Mass spectrometry (MS); Piece; Ratio; Sample, optional label/labor no; Sample code/label; see reference(s); Sulfur, total; δ34S, pyrite; δ34S, sulfide About 150 basalt samples from Hole 504B, near the Costa Rica Rift were analyzed for sulfur content and sulfur-isotope composition. The basement in Hole 504B can be divided into an upper part, which has oxidative alteration (274.5-550 m below sea floor), and a lower part, which has nonoxidative alteration (550-835 m below sea floor) (the interval from 540 to 585 meters actually is transitional). This division is reflected in both the sulfur content and the sulfurisotope composition. Oxidative alteration of basalts by sea water at low temperatures has resulted in a depletion in sulfur in the upper part of the hole (mostly less than 600 ppm S) as compared to fresh sulfur-saturated oceanic tholeiites (900-1200 ppm S). High amounts of sulfur in the lower part of the hole are a result of precipitation of secondary pyrite under non-oxidative or weakly oxidative conditions from solutions which dissolved igneous sulfides. The average sulfur-isotope composition of the primary igneous sulfides is d34S = -0.01 per mil, which is close to the assumed mantle sulfur composition (d34S = 0 per mil. Pyrite and sulfate sulfur extracted together in a separate preparation step (as "pyrite-sulfate" sulfur) indicate addition of sea-water sulfate to the upper part of the basalts. The d34S of secondary pyrite isolated by hand-picking varies between -8.0 and +5.8 per mil; the "pyrite-sulfate" sulfur (d34S = -4.8 to +10.5 per mil), as well as that of the isolated pyrite, may have originated in the precipitation of pyrite from solutions containing sulfur from the dissolution of igneous sulfides, but addition of sulfur transported by hydrothermal solutions cannot be excluded. |
| title | (Table 1) Sulfur isotopes, total sulfur, and degree of oxidation of basalt samples from DSDP Hole 69-504B and 70-504B |
| topic | 69-504B; 70-504B; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Event label; Glomar Challenger; Leg69; Leg70; Mass spectrometry (MS); Piece; Ratio; Sample, optional label/labor no; Sample code/label; see reference(s); Sulfur, total; δ34S, pyrite; δ34S, sulfide |
| url | https://doi.org/10.1594/PANGAEA.816535 |