Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B
Dunite and gabbroic materials recovered from Hole 1271B, Ocean Drilling Program (ODP) Leg 209, were examined for mineral chemistry to understand melt flow and melt-mantle reactions in the shallowest upper mantle of the Mid-Atlantic Ridge near the 15°20' Fracture Zone. Hole 1271B was drilled to...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.776495 2024-09-15T18:24:20+00:00 Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B Takazawa, Eiichi Abe, Natsue Seyler, Monique Meurer, William P LATITUDE: 15.036480 * LONGITUDE: -44.948530 * DATE/TIME START: 2003-06-04T02:45:00 * DATE/TIME END: 2003-06-07T07:45:00 2007 application/zip, 3 datasets https://doi.pangaea.de/10.1594/PANGAEA.776495 https://doi.org/10.1594/PANGAEA.776495 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.776495 https://doi.org/10.1594/PANGAEA.776495 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Takazawa, Eiichi; Abe, Natsue; Seyler, Monique; Meurer, William P (2007): Hybridization of dunite and gabbroic materials in Hole 1271B from Mid-Atlantic Ridge 15°N: Implications for melt flow and reaction in the upper mantle. In: Kelemen, PB; Kikawa, E; Miller; DJ (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 209, 1-23, https://doi.org/10.2973/odp.proc.sr.209.005.2007 209-1271B DRILL Drilling/drill rig Joides Resolution Leg209 North Atlantic Ocean Ocean Drilling Program ODP dataset publication series 2007 ftpangaea https://doi.org/10.1594/PANGAEA.77649510.2973/odp.proc.sr.209.005.2007 2024-08-21T00:02:25Z Dunite and gabbroic materials recovered from Hole 1271B, Ocean Drilling Program (ODP) Leg 209, were examined for mineral chemistry to understand melt flow and melt-mantle reactions in the shallowest upper mantle of the Mid-Atlantic Ridge near the 15°20' Fracture Zone. Hole 1271B was drilled to 103.8 meters below seafloor on the inner corner high along the south wall of the 15°20' Fracture Zone. The total length of core collected was 15.9 m (recovery = ~15%). The dominant rock type in Hole 1271B is dunite, followed by brown amphibole gabbro, olivine gabbro, and troctolite, along with minor amounts of harzburgite and olivine gabbronorite. A large proportion of the dunite is associated with gabbroic rocks in Hole 1271B, similar to those observed in the Mohorovicic (Moho) transition zone of the Oman ophiolite, indicating significant magmatic activity in this region near the 15°20' Fracture Zone. Olivine Fo content varies from 89.2 to 91.2 in impregnated dunite and from 85.6 to 88.6 in troctolite, olivine gabbro, and olivine gabbronorite. Spinel Cr# (= 100 x Cr/[Cr + Al] molar ratio) ranges from 38.9 to 62.7 in dunite and from 46.3 to 57.6 in troctolites, olivine gabbro, and olivine gabbronorite. Compositional trends for spinel from dunite through troctolite toward olivine gabbro/gabbronorite are characterized by increases in TiO2, Cr#, and Fe3+#, very similar to those reported from Hess Deep Site 895. Olivine gabbro, olivine gabbronorite, and troctolite in Hole 1271B are considered to have formed as hybrid rocks between dunite and an evolved melt in the walls of a melt channel in the shallowest upper mantle that is tens of meters wide. The melt trapped in the wall rock crystallized plagioclase and clinopyroxene. On the other hand, dunite in the center of the melt channel became more refractory by melt-mantle reactions, increasing spinel Cr# to 62.5. Other/Unknown Material North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-44.948530,-44.948530,15.036480,15.036480) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
209-1271B DRILL Drilling/drill rig Joides Resolution Leg209 North Atlantic Ocean Ocean Drilling Program ODP |
spellingShingle |
209-1271B DRILL Drilling/drill rig Joides Resolution Leg209 North Atlantic Ocean Ocean Drilling Program ODP Takazawa, Eiichi Abe, Natsue Seyler, Monique Meurer, William P Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B |
topic_facet |
209-1271B DRILL Drilling/drill rig Joides Resolution Leg209 North Atlantic Ocean Ocean Drilling Program ODP |
description |
Dunite and gabbroic materials recovered from Hole 1271B, Ocean Drilling Program (ODP) Leg 209, were examined for mineral chemistry to understand melt flow and melt-mantle reactions in the shallowest upper mantle of the Mid-Atlantic Ridge near the 15°20' Fracture Zone. Hole 1271B was drilled to 103.8 meters below seafloor on the inner corner high along the south wall of the 15°20' Fracture Zone. The total length of core collected was 15.9 m (recovery = ~15%). The dominant rock type in Hole 1271B is dunite, followed by brown amphibole gabbro, olivine gabbro, and troctolite, along with minor amounts of harzburgite and olivine gabbronorite. A large proportion of the dunite is associated with gabbroic rocks in Hole 1271B, similar to those observed in the Mohorovicic (Moho) transition zone of the Oman ophiolite, indicating significant magmatic activity in this region near the 15°20' Fracture Zone. Olivine Fo content varies from 89.2 to 91.2 in impregnated dunite and from 85.6 to 88.6 in troctolite, olivine gabbro, and olivine gabbronorite. Spinel Cr# (= 100 x Cr/[Cr + Al] molar ratio) ranges from 38.9 to 62.7 in dunite and from 46.3 to 57.6 in troctolites, olivine gabbro, and olivine gabbronorite. Compositional trends for spinel from dunite through troctolite toward olivine gabbro/gabbronorite are characterized by increases in TiO2, Cr#, and Fe3+#, very similar to those reported from Hess Deep Site 895. Olivine gabbro, olivine gabbronorite, and troctolite in Hole 1271B are considered to have formed as hybrid rocks between dunite and an evolved melt in the walls of a melt channel in the shallowest upper mantle that is tens of meters wide. The melt trapped in the wall rock crystallized plagioclase and clinopyroxene. On the other hand, dunite in the center of the melt channel became more refractory by melt-mantle reactions, increasing spinel Cr# to 62.5. |
format |
Other/Unknown Material |
author |
Takazawa, Eiichi Abe, Natsue Seyler, Monique Meurer, William P |
author_facet |
Takazawa, Eiichi Abe, Natsue Seyler, Monique Meurer, William P |
author_sort |
Takazawa, Eiichi |
title |
Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B |
title_short |
Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B |
title_full |
Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B |
title_fullStr |
Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B |
title_full_unstemmed |
Geochemical composition of olivine, spinel and amphibole in ODP Hole 209-1271B |
title_sort |
geochemical composition of olivine, spinel and amphibole in odp hole 209-1271b |
publisher |
PANGAEA |
publishDate |
2007 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.776495 https://doi.org/10.1594/PANGAEA.776495 |
op_coverage |
LATITUDE: 15.036480 * LONGITUDE: -44.948530 * DATE/TIME START: 2003-06-04T02:45:00 * DATE/TIME END: 2003-06-07T07:45:00 |
long_lat |
ENVELOPE(-44.948530,-44.948530,15.036480,15.036480) |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Supplement to: Takazawa, Eiichi; Abe, Natsue; Seyler, Monique; Meurer, William P (2007): Hybridization of dunite and gabbroic materials in Hole 1271B from Mid-Atlantic Ridge 15°N: Implications for melt flow and reaction in the upper mantle. In: Kelemen, PB; Kikawa, E; Miller; DJ (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 209, 1-23, https://doi.org/10.2973/odp.proc.sr.209.005.2007 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.776495 https://doi.org/10.1594/PANGAEA.776495 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.77649510.2973/odp.proc.sr.209.005.2007 |
_version_ |
1810464676459315200 |