| Remnants of oceanic lower crust in the subcontinental lithospheric mantle: Trace element and Sr-Nd-O isotope evidence from aluminous garnet pyroxenite xenoliths from Jiaohe, Northeast China | |
| Song-Yue Yu; Yi-Gang Xu; Jin-Long Ma; Yong-Fei Zheng; Yong-Sheng Kuang; Lu-Bing Hong; Wen-Chun Ge; Lai-Xi Tong | |
| 2010 | |
| Source Publication | Earth and Planetary Science Letters
 |
| Volume | 297Issue:3-4Pages:413-422 |
| Abstract | Pyroxenite xenoliths entrained in alkali basalts are usually interpreted to be high pressure cumulates from mantle-derived melts. However, those from Jiaohe, Northeast China may have originated from subducted oceanic crust. Their high bulk Al(2)O(3) contents (12.2-17.4%) and Mg# (up to 0.88) resemble those of olivine-bearing cumulative gabbros. A crustal origin for the Jiaohe pyroxenites from plagioclase-bearing protoliths is further supported by positive Eu and Sr anomalies in both whole rock and in garnet and clinopyroxene analyses, low HREE abundances in garnet and low delta(18)O (4.9-5.1 parts per thousand) relative to typical mantle values (5.5 parts per thousand). Compared with average values for the corresponding mantle minerals, the delta(18)O values of the Jiaohe clinopyroxene (4.5-5.4 parts per thousand) are lower, the delta(18)O values of garnet (5.1-5.6 parts per thousand) are similar, whereas those of spinet are higher (5.2 parts per thousand). In particular, there are disequilibrium O isotopic fractionations between garnet/spinet and clinopyroxene, resembling those of plagioclase/clinopyroxene pairs in seawater-altered oceanic crust. This is attributed to spinet and garnet inheriting their O isotope characteristics from plagioclase prior to transformation to these minerals during subduction metamorphism of altered oceanic gabbros, without isotopic re-equilibration at mantle conditions. Identification of remnants of subducted oceanic crust in the subcontinental lithospheric mantle is important to understanding mantle heterogeneity and genesis of intraplate magmatism. |
| Keyword | Pyroxenite Xenoliths Eu Anomaly o Isotope Inheritance Mineralogical Transformation Subducted Gabbroic Oceanic Crust Subcontinental Lithospheric Mantle Northeast China |
| Subject Area | 矿床地球化学 |
| Indexed By | SCI |
| Language | 英语 |
| Document Type | 期刊论文 |
| Identifier | http://ir.gyig.ac.cn/handle/352002/4959 |
| Collection | 矿床地球化学国家重点实验室_矿床地球化学国家重点实验室_期刊论文 |
| Recommended Citation GB/T 7714 | Song-Yue Yu,Yi-Gang Xu,Jin-Long Ma,et al. Remnants of oceanic lower crust in the subcontinental lithospheric mantle: Trace element and Sr-Nd-O isotope evidence from aluminous garnet pyroxenite xenoliths from Jiaohe, Northeast China[J]. Earth and Planetary Science Letters,2010,297(3-4):413-422. |
| APA | Song-Yue Yu.,Yi-Gang Xu.,Jin-Long Ma.,Yong-Fei Zheng.,Yong-Sheng Kuang.,...&Lai-Xi Tong.(2010).Remnants of oceanic lower crust in the subcontinental lithospheric mantle: Trace element and Sr-Nd-O isotope evidence from aluminous garnet pyroxenite xenoliths from Jiaohe, Northeast China.Earth and Planetary Science Letters,297(3-4),413-422. |
| MLA | Song-Yue Yu,et al."Remnants of oceanic lower crust in the subcontinental lithospheric mantle: Trace element and Sr-Nd-O isotope evidence from aluminous garnet pyroxenite xenoliths from Jiaohe, Northeast China".Earth and Planetary Science Letters 297.3-4(2010):413-422. |
| Files in This Item: | Download All | |||||
| File Name/Size | DocType | Version | Access | License | ||
| Remnants of oceanic （835KB） | 开放获取 | License | View Download | |||
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment