| WANG Wei,CHU Fengyou,ZHU Jihao,DONG Yanhui,YU Xing,CHEN Ling,LI Zhenggang. 2013. Mantle melting beneath the Southwest Indian Ridge: signals from clinopyroxene in abyssal peridotites. Acta Oceanologica Sinica, 32(12):50－59 |
| Mantle melting beneath the Southwest Indian Ridge: signals from clinopyroxene in abyssal peridotites |
| Mantle melting beneath the Southwest Indian Ridge: signals from clinopyroxene in abyssal peridotites |
| Received:May 17, 2013 Revised:August 16, 2013 |
| DOI：10.1007/s13131-013-0387-0 |
| Key words:partial melting abyssal peridotite clinopyroxene major elements SWIR |
| 中文关键词: partial melting abyssal peridotite clinopyroxene major elements SWIR |
| 基金项目:The National Key Basic Research Program of China under contract No. 2013CB429700; National Special Fund for the 12th Five Year Plan of COMRA under contract Nos DY125-12-R-02 and DY125-11-R-05; Shandong Province Natural Science Foundation of China for Distinguished Young Scholars under contract No. JQ200913; the National Natural Science Foundation of China under contract Nos 40830849, 40976027 and 40906029. |
| Author Name | Affiliation | E-mail | | WANG Wei | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | | | CHU Fengyou | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | chu@sio.org.cn | | ZHU Jihao | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | | | DONG Yanhui | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | | | YU Xing | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | | | CHEN Ling | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | | | LI Zhenggang | The Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China | |
|
| Hits: 1707 |
| Download times: 2375 |
| Abstract: |
| The mineral chemistry and texture of clinopyroxenes in peridotite from the Kingkong tectonic zone of the Southwest Indian Ridge segment in an effort to constrain mantle melting beneath this slow-spreading ridge are reported. There are three types of clinopyroxenes in the abyssal peridotites: coarse-grained, intergranular and exsolved. The compositional variations among these three types suggest that the coarse-grained clinopyroxene is a mantle-derived source. The Al, Na and Ti contents and the Na/Ti ratio of the coarse-grained clinopyroxene may be used to monitor the degree of partial melting, combined with the contradistinction with Spinel Cr#, which is calculated to be between 7.9% and 14.9%, and may represent low degrees of melting in the global ocean ridge system. The along-axis compositional variations in the coarse-grained clinopyroxene suggest that the degree of partial melting is primarily controlled by the transform faults on both sides of the ridge. Nonetheless, the northwestern side of the ridge may be affected by a hypothesised detachment fault as documented by the calculated P-T conditions. Simultaneously high Na and low Ti contents in the coarse-grained clinopyroxene points to mantle heterogeneities along the ridge axis. |
| 中文摘要: |
| The mineral chemistry and texture of clinopyroxenes in peridotite from the Kingkong tectonic zone of the Southwest Indian Ridge segment in an effort to constrain mantle melting beneath this slow-spreading ridge are reported. There are three types of clinopyroxenes in the abyssal peridotites: coarse-grained, intergranular and exsolved. The compositional variations among these three types suggest that the coarse-grained clinopyroxene is a mantle-derived source. The Al, Na and Ti contents and the Na/Ti ratio of the coarse-grained clinopyroxene may be used to monitor the degree of partial melting, combined with the contradistinction with Spinel Cr#, which is calculated to be between 7.9% and 14.9%, and may represent low degrees of melting in the global ocean ridge system. The along-axis compositional variations in the coarse-grained clinopyroxene suggest that the degree of partial melting is primarily controlled by the transform faults on both sides of the ridge. Nonetheless, the northwestern side of the ridge may be affected by a hypothesised detachment fault as documented by the calculated P-T conditions. Simultaneously high Na and low Ti contents in the coarse-grained clinopyroxene points to mantle heterogeneities along the ridge axis. |
|
HTML
View Full Text
View/Add Comment Download reader |
| Close |
|
|
|
