Enregistré dans:
| Auteurs principaux: | , , |
|---|---|
| Format: | Dataset Open Access |
| Langue: | en |
| Publié: |
PANGAEA
2009
|
| Sujets: | |
| Accès en ligne: | https://doi.org/10.1594/PANGAEA.772913 |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1867170461256777728 |
|---|---|
| author | Jöns, Niels Bach, Wolfgang Schroeder, Timothy |
| author_facet | Jöns, Niels Bach, Wolfgang Schroeder, Timothy |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | We examined small-scale shear zones in drillcore samples of abyssal peridotites from the Mid-Atlantic Ridge. These shear zones are associated with veins consisting of chlorite + actinolite/tremolite assemblages, with accessory phases zircon and apatite, and they are interpreted as altered plagiogranite melt impregnations, which originate from hydrous partial melting of gabbroic intrusion in an oceanic detachment fault. Ti-in-zircon thermometry yields temperatures around 820°C for the crystallization of the evolved melt. Reaction path modeling indicates that the alteration assemblage includes serpentine of the adjacent altered peridotites. Based on the model results, we propose that formation of chlorite occurred at higher temperatures than serpentinization, thus leading to strain localization around former plagiogranites during alteration. The detachment fault represents a major pathway for fluids through the oceanic crust, as evidenced by extremely low d18O of altered plagiogranite veins (+3.0-4.2 per mil) and adjacent serpentinites (+ 2.6-3.7 per mil). The uniform oxygen isotope data indicate that fluid flow in the detachment fault system affected veins and adjacent host serpentinites likewise. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_772913 |
| institution | PANGAEA |
| language | en |
| publishDate | 2009 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Chemistry of minerals from amphibole-chlorite veins of ODP Site 209-1270 Jöns, Niels Bach, Wolfgang Schroeder, Timothy 209-1270C; 209-1270D; DRILL; Drilling/drill rig; Joides Resolution; Leg209; North Atlantic Ocean; Ocean Drilling Program; ODP We examined small-scale shear zones in drillcore samples of abyssal peridotites from the Mid-Atlantic Ridge. These shear zones are associated with veins consisting of chlorite + actinolite/tremolite assemblages, with accessory phases zircon and apatite, and they are interpreted as altered plagiogranite melt impregnations, which originate from hydrous partial melting of gabbroic intrusion in an oceanic detachment fault. Ti-in-zircon thermometry yields temperatures around 820°C for the crystallization of the evolved melt. Reaction path modeling indicates that the alteration assemblage includes serpentine of the adjacent altered peridotites. Based on the model results, we propose that formation of chlorite occurred at higher temperatures than serpentinization, thus leading to strain localization around former plagiogranites during alteration. The detachment fault represents a major pathway for fluids through the oceanic crust, as evidenced by extremely low d18O of altered plagiogranite veins (+3.0-4.2 per mil) and adjacent serpentinites (+ 2.6-3.7 per mil). The uniform oxygen isotope data indicate that fluid flow in the detachment fault system affected veins and adjacent host serpentinites likewise. |
| title | Chemistry of minerals from amphibole-chlorite veins of ODP Site 209-1270 |
| topic | 209-1270C; 209-1270D; DRILL; Drilling/drill rig; Joides Resolution; Leg209; North Atlantic Ocean; Ocean Drilling Program; ODP |
| url | https://doi.org/10.1594/PANGAEA.772913 |