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author Blusztajn, Jerzy S
Hart, Stanley R
Ravizza, Gregory E
Dick, Henry J B
author_facet Blusztajn, Jerzy S
Hart, Stanley R
Ravizza, Gregory E
Dick, Henry J B
collection Datos científicos de ciencias marinas y ambientales
contents We present osmium isotopic compositions and Os, Re and platinum-group element (PGE) contents in the lower oceanic crust gabbros from ODP Site 735B on the Southwest Indian Ridge. The average gabbros are very depleted in PGEs, e.g. the Os concentrations are very low and range from 0.5 to 38 ppt. One troctolite sample is an exception, containing, e.g. 376 ppt Os, 396 ppt Ir and 8 ppb Pd. Re contents are extremely heterogeneous, ranging from 128 ppt to 28 ppb. The present day 187Os/188Os varies from 0.140 to 0.467, and correlates with Rb/Cs, suggesting that seawater alteration affected the Os isotopic system. The average Os content in the lower oceanic crust is about 9 ppt while median value for Re is about 487 ppt. Such very high Re/Os is relatively similar to the upper MORB-type oceanic crust, indicating that recycled ocean crust basalts and gabbros will rapidly develop very radiogenic Os isotopic signatures.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_706146
institution PANGAEA
language en
publishDate 2000
publisher PANGAEA
record_format pangaea
spellingShingle (Tables 1-2) Re, Os concentrations and 187Os/188Os of gabbros from ODP Site 118-735B
Blusztajn, Jerzy S
Hart, Stanley R
Ravizza, Gregory E
Dick, Henry J B
118-735B; Calculated; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Isotope dilution inductively coupled plasma mass spectrometry; Joides Resolution; Leg118; Main Lithology; Ocean Drilling Program; ODP; Osmium; Osmium-187/Osmium-188 ratio; Rhenium; Rhenium-187/Osmium-188 ratio; Sample code/label; Sample code/label 2; South Indian Ridge, South Indian Ocean
We present osmium isotopic compositions and Os, Re and platinum-group element (PGE) contents in the lower oceanic crust gabbros from ODP Site 735B on the Southwest Indian Ridge. The average gabbros are very depleted in PGEs, e.g. the Os concentrations are very low and range from 0.5 to 38 ppt. One troctolite sample is an exception, containing, e.g. 376 ppt Os, 396 ppt Ir and 8 ppb Pd. Re contents are extremely heterogeneous, ranging from 128 ppt to 28 ppb. The present day 187Os/188Os varies from 0.140 to 0.467, and correlates with Rb/Cs, suggesting that seawater alteration affected the Os isotopic system. The average Os content in the lower oceanic crust is about 9 ppt while median value for Re is about 487 ppt. Such very high Re/Os is relatively similar to the upper MORB-type oceanic crust, indicating that recycled ocean crust basalts and gabbros will rapidly develop very radiogenic Os isotopic signatures.
title (Tables 1-2) Re, Os concentrations and 187Os/188Os of gabbros from ODP Site 118-735B
topic 118-735B; Calculated; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Isotope dilution inductively coupled plasma mass spectrometry; Joides Resolution; Leg118; Main Lithology; Ocean Drilling Program; ODP; Osmium; Osmium-187/Osmium-188 ratio; Rhenium; Rhenium-187/Osmium-188 ratio; Sample code/label; Sample code/label 2; South Indian Ridge, South Indian Ocean
url https://doi.org/10.1594/PANGAEA.706146