| 四顶黑山镁铁质—超镁铁质岩Sm-Nd等时线年龄及其意义 |
| |
| 引用本文： | 史文全,代文军.四顶黑山镁铁质—超镁铁质岩Sm-Nd等时线年龄及其意义[J].甘肃地质学报,2008,17(1):13-16,22. |
| |
| 作者姓名： | 史文全 代文军 |
| |
| 作者单位： | 甘肃省地矿局第三地勘院 甘肃兰州730050 |
| |
| 基金项目： | 中国地质调查局《1∶5万红岭幅等3幅区域地质调查》项目(编号:200113000057)部分成果 |
| |
| 摘 要： | 四顶黑山岩体主要由超镁铁质岩和镁铁质岩组成。超镁铁质岩由橄榄岩、角闪橄榄岩、辉橄岩、辉石岩等组成;镁铁质岩由辉长岩、角闪辉长岩、橄榄辉长岩等组成。本次对辉长岩进行了全岩Sm-Nd同位素分析,得到的等时线年龄为327±9.0Ma,初始εNd（t）=＋3.97,表明镁铁质—超镁铁质岩中辉长岩形成于早石炭世末。属于富集地幔向亏损地幔过渡类型。这一年龄的确定,为探讨北山—天山结合部晚古生代镁铁质—超镁铁质岩的成因机制和该区的区域地质演化提供了有效的年代学依据。
|
| 关 键 词： | 镁铁质—超镁铁质岩 Sm-Nd等时线年龄 四顶黑山 北山—天山 |
Sm-Nd ISOCHRON AGE OF MAFIC AND ULTRAMAFIC ROCK IN SIDINGHEISHAN AND ITS' SIGNIFICANCE |
| |
| SHI Wen-quan and DAI Wen-jun.Sm-Nd ISOCHRON AGE OF MAFIC AND ULTRAMAFIC ROCK IN SIDINGHEISHAN AND ITS' SIGNIFICANCE[J].Acta Geologica Gansu,2008,17(1):13-16,22. |
| |
| Authors: | SHI Wen-quan and DAI Wen-jun |
| |
| Institution: | (No. 3 Geology and Mineral Exploration Team, Gansu Provincial Bureau of Geology and Mineral Exploration and Development, Lanzhou 730050, China) |
| |
| Abstract: | Sidingheishan rock mass chiefly consist of the ultramafic rock composed of peridorite, cortlandtite, pyrolite and pyroxenite, and the mafic rock composed of gabbro, bojite and olivine gabbro. The Sm-Nd isotopic analysis to gabbro show that the isochron age is 327±9.0Ma,εNd（t）is 3.97, which suggest that the gabbro within mafic and ultramafic rock formed in the end of the early Carboniferous, and is the transitional type from enriched to depleted mantle. These results provide the key chronological evidences for study on genetic mechanism of mafic and ultramafic rock in the joint part between Tianshan and Beishan during the late Paleozoic, and on regional geological evolution in this area. |
| |
| Keywords: | mafic-ultramafic rock Sm-Nd isochron Sidingheishan Beishan Tianshan |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《甘肃地质学报》浏览原始摘要信息 |
| 点击此处可从《甘肃地质学报》下载免费的PDF全文 |
