Geochemistry of ODP Leg 115 basalts
Fuente:
PANGAEA
Salvato in:
| Autori principali: | , |
|---|---|
| Natura: | Dataset Open Access |
| Lingua: | en |
| Pubblicazione: |
PANGAEA
1990
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1867171360765116416 |
|---|---|
| author | Tatsumi, Yoshiyuki Nohda, Susumu |
| author_facet | Tatsumi, Yoshiyuki Nohda, Susumu |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Melting-phase relations at high pressures and Sr-Nd isotopic compositions are reported for basalts collected from the western Indian Ocean during Ocean Drilling Program Leg 115. Based on the concentrations of high-field-strength elements, we have subdivided the basalts into eight groups. A tholeiitic primary magma estimated using an olivine maximum fractionation model is representative of depleted lavas. This melt is in equilibrium with lherzolite minerals at 1.3 GPa and 1330°C under dry conditions. Also, an alkaline primary magma, representative of enriched lavas, is not saturated with orthopyroxene under dry conditions, but it is saturated with lherzolite minerals under CO2-saturated conditions at 1.7 GPa and 1350°C. These results imply that the tholeiitic magmas were segregated from mantle diapirs at shallower levels than the alkaline magmas. The highest 143Nd/144Nd value is obtained for the most depleted tholeiitic basalts, and the lowest value corresponds to the enriched alkaline basalt. The Sr isotopes of the basalts range from 0.70378 to 0.70449 and are inversely correlated with the Nd isotopic values. The present experimental and geochemical data suggest that depleted mantle material is underlain by the enriched material in the upper mantle beneath the region. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_756147 |
| institution | PANGAEA |
| language | en |
| publishDate | 1990 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Geochemistry of ODP Leg 115 basalts Tatsumi, Yoshiyuki Nohda, Susumu 115-706C; 115-707C; 115-713A; 115-715A; DRILL; Drilling/drill rig; Indian Ocean; Joides Resolution; Lakshadweep Sea; Leg115; Ocean Drilling Program; ODP; South Indian Ridge, South Indian Ocean Melting-phase relations at high pressures and Sr-Nd isotopic compositions are reported for basalts collected from the western Indian Ocean during Ocean Drilling Program Leg 115. Based on the concentrations of high-field-strength elements, we have subdivided the basalts into eight groups. A tholeiitic primary magma estimated using an olivine maximum fractionation model is representative of depleted lavas. This melt is in equilibrium with lherzolite minerals at 1.3 GPa and 1330°C under dry conditions. Also, an alkaline primary magma, representative of enriched lavas, is not saturated with orthopyroxene under dry conditions, but it is saturated with lherzolite minerals under CO2-saturated conditions at 1.7 GPa and 1350°C. These results imply that the tholeiitic magmas were segregated from mantle diapirs at shallower levels than the alkaline magmas. The highest 143Nd/144Nd value is obtained for the most depleted tholeiitic basalts, and the lowest value corresponds to the enriched alkaline basalt. The Sr isotopes of the basalts range from 0.70378 to 0.70449 and are inversely correlated with the Nd isotopic values. The present experimental and geochemical data suggest that depleted mantle material is underlain by the enriched material in the upper mantle beneath the region. |
| title | Geochemistry of ODP Leg 115 basalts |
| topic | 115-706C; 115-707C; 115-713A; 115-715A; DRILL; Drilling/drill rig; Indian Ocean; Joides Resolution; Lakshadweep Sea; Leg115; Ocean Drilling Program; ODP; South Indian Ridge, South Indian Ocean |
| url | https://doi.org/10.1594/PANGAEA.756147 |