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| Format: | Dataset Open Access |
| Language: | en |
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PANGAEA
2012
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| Subjects: | |
| Online Access: | https://doi.org/10.1594/PANGAEA.812212 |
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| _version_ | 1867169082768359424 |
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| author | Barnes, Jaime D Cisneros, Miguel |
| author_facet | Barnes, Jaime D Cisneros, Miguel |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Bulk chlorine concentrations and chlorine stable isotope compositions were determined for hydrothermally altered basalt (extrusive lavas and sheeted dikes) and gabbro samples (n = 50) from seven DSDP/ODP/IODP drill sites. These altered oceanic crust (AOC) samples span a range of crustal ages, tectonic settings, alteration type, and crustal depth. Bulk chlorine concentrations range from < 0.01 wt.% to 0.09 wt.%. In general, higher chlorine concentrations coincide with an increase in temperature of alteration and amphibole content. d37Cl values of whole rock AOC samples range from -1.4 to +1.8 per mil. High d37Cl values (>=~0.5 per mil) are associated with areas of higher amphibole content. This observation is consistent with theoretical calculations that estimate amphibole should be enriched in 37Cl compared to co-existing fluid. Negative to near zero d37Cl values are found in areas dominated by clay minerals. Chlorine geochemistry is a rough indicator of metamorphic grade and mineralogy. AOC is a major Cl host in the subducting oceanic lithospheric slab. Here we show that bulk chlorine concentrations are ~3 times higher than previous estimates resulting in a greater contribution of Cl to the mantle. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_812212 |
| institution | PANGAEA |
| language | en |
| publishDate | 2012 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 2) Chlorine geochemistry and mineralogy of altered oceanic crust samples Barnes, Jaime D Cisneros, Miguel 118-735B; 129-801C; 137-504B; 140-504B; 147-894F; 148-504B; 185-801C; 206-1256D; 309-U1256D; 37-332B; 52-418A; 53-418A; 70-504B; 83-504B; Amphibole; Chlorine; Chlorite; Deep Sea Drilling Project; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Elevation of event; Event label; Exp309; Glomar Challenger; Instrumental neutron activation analysis (INAA) (Reimann et al., 1998); Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Joides Resolution; Latitude of event; Leg118; Leg129; Leg137; Leg140; Leg147; Leg148; Leg185; Leg206; Leg37; Leg52; Leg53; Leg70; Leg83; Lithology/composition/facies; Longitude of event; Mass spectrometer, Finnigan, MAT 253; North Atlantic/CONT RISE; North Atlantic/VALLEY; North Pacific Ocean; Ocean Drilling Program; ODP; Sample code/label; South Indian Ridge, South Indian Ocean; Superfast Spreading Rate Crust 2; X-ray diffraction (XRD); δ37Cl Bulk chlorine concentrations and chlorine stable isotope compositions were determined for hydrothermally altered basalt (extrusive lavas and sheeted dikes) and gabbro samples (n = 50) from seven DSDP/ODP/IODP drill sites. These altered oceanic crust (AOC) samples span a range of crustal ages, tectonic settings, alteration type, and crustal depth. Bulk chlorine concentrations range from < 0.01 wt.% to 0.09 wt.%. In general, higher chlorine concentrations coincide with an increase in temperature of alteration and amphibole content. d37Cl values of whole rock AOC samples range from -1.4 to +1.8 per mil. High d37Cl values (>=~0.5 per mil) are associated with areas of higher amphibole content. This observation is consistent with theoretical calculations that estimate amphibole should be enriched in 37Cl compared to co-existing fluid. Negative to near zero d37Cl values are found in areas dominated by clay minerals. Chlorine geochemistry is a rough indicator of metamorphic grade and mineralogy. AOC is a major Cl host in the subducting oceanic lithospheric slab. Here we show that bulk chlorine concentrations are ~3 times higher than previous estimates resulting in a greater contribution of Cl to the mantle. |
| title | (Table 2) Chlorine geochemistry and mineralogy of altered oceanic crust samples |
| topic | 118-735B; 129-801C; 137-504B; 140-504B; 147-894F; 148-504B; 185-801C; 206-1256D; 309-U1256D; 37-332B; 52-418A; 53-418A; 70-504B; 83-504B; Amphibole; Chlorine; Chlorite; Deep Sea Drilling Project; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Elevation of event; Event label; Exp309; Glomar Challenger; Instrumental neutron activation analysis (INAA) (Reimann et al., 1998); Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Joides Resolution; Latitude of event; Leg118; Leg129; Leg137; Leg140; Leg147; Leg148; Leg185; Leg206; Leg37; Leg52; Leg53; Leg70; Leg83; Lithology/composition/facies; Longitude of event; Mass spectrometer, Finnigan, MAT 253; North Atlantic/CONT RISE; North Atlantic/VALLEY; North Pacific Ocean; Ocean Drilling Program; ODP; Sample code/label; South Indian Ridge, South Indian Ocean; Superfast Spreading Rate Crust 2; X-ray diffraction (XRD); δ37Cl |
| url | https://doi.org/10.1594/PANGAEA.812212 |