| 藏北蛇绿岩中尖晶石类矿物的化学成分 |
| |
| 引用本文： | 邓万明.藏北蛇绿岩中尖晶石类矿物的化学成分[J].地质科学,1988,0(2):121-127. |
| |
| 作者姓名： | 邓万明 |
| |
| 作者单位： | 中国科学院地质研究所 |
| |
| 摘 要： | 本文根据东巧蛇绿岩中镁铁质-超镁铁质杂岩的尖晶石化学成分特征,讨论了该区变质橄榄岩产生的构造位置、上地幔部分熔融程度等。东巧蛇绿岩组合代表一种过渡型岩石圈物质,这已为岩石学和地球化学的研究所支持。本文从矿物学方面又提供了新的论据。
|
| 关 键 词： | 变质橄榄岩 大洋岩石圈 部分熔融程度 弧后盆地 母岩浆 |
| 收稿时间： | 1986-12-01 |
| 修稿时间： | 1986-12-01; |
CHEMICAL COMPOSITIONS OF SPINEL GROUP FROM METAMORPHIC PERIDOTITES AND CUMULATES IN NORTH TIBETAN OPHIOLITE |
| |
| Deng Wanming.CHEMICAL COMPOSITIONS OF SPINEL GROUP FROM METAMORPHIC PERIDOTITES AND CUMULATES IN NORTH TIBETAN OPHIOLITE[J].Chinese Journal of Geology,1988,0(2):121-127. |
| |
| Authors: | Deng Wanming |
| |
| Institution: | Institute of Geology, Academia Sinica, Beijing |
| |
| Abstract: | Chemical compositions of minerals analysed by microprobe are reported for spinel group including Iherzolite, harzburgite, dunite and cumulates in Dongqiao ophiolite belt. The resutls are advantageous to interpret origin of the oplliolite.Spinels occurring as accessory minerals in the Iherzolite, harzhurgite and dunite have Cr/Cr + Al ratios that encompass a wide range. It is clear that the high-Al spinel appears only in the Iherzolite, while the harzburgite and dunite are characterized by high-Cr spinels. The pattern Alpine-type peridotite belongs to Type 11 divided by Dick and Bullen (1984). This pattern represents a complex multi-stage melting history of the upper mantle, which is different from that at mid-oceanic ridge. Such peridotite assemblage is probably situated in transitional setting from island arc to oceanic lithosphere, or may be a oceanic crust-upper mantle structure of back-arc basin between the active continental margin and typical oceanic lithosphere. Accordingly, Dongqiao ophiolite is relics of a immature oceanic lithosphere formed in this tectonic environment. |
| |
| Keywords: | metamorphic peridotite oceanic lithosphere partial melting degree back-arc basin parent magma |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《地质科学》浏览原始摘要信息 |
| 点击此处可从《地质科学》下载免费的PDF全文 |
