| 甘肃东部陇山群中斜长角闪岩的形成时代和构造背景 |
| |
| 引用本文： | 吴茂炳,傅碧宏,刘春燕.甘肃东部陇山群中斜长角闪岩的形成时代和构造背景[J].地球与环境,2000,28(2):45-50. |
| |
| 作者姓名： | 吴茂炳 傅碧宏 刘春燕 |
| |
| 作者单位： | 1. 中国科学院兰州地质研究所,兰州,730000
2. 甘肃省地矿局地质科学研究所,兰州,730000 |
| |
| 摘 要： | 陇山群中斜长角闪岩的地质－地球化学特征研究表明,斜长用问岩是分两期形成的,其Sm－Nd等时线年龄分别为983±22Ma和756±97Ma,源区为类似于现在洋中脊型的地幔,说明在中元古代形成的裂谷此时已趋成熟,具有相当的规模。微量元素和稀土元素的特征也支持该认识。作者认为斜长用闪岩的原岩是侵入陇山群的辉绿岩墙或基性岩脉,是800～1000Ma（晋宁期）裂谷作用的产物,裂谷活动的扩张速率为2～5cm／a。
|
| 关 键 词： | 陇山群 斜长角闪岩 Sm－Nd等时线年龄 地球化学 构造环境 甘肃东部 |
Sm-Nd ISOCHRON AGE AND TECTONIC SETTING OF AMPHIBOLITES OF THE LONGSHAN GROUP IN EASTERN GANSU PROVINCE |
| |
| Wu Maobing,Fu Bihong,Liu Chunyan.Sm-Nd ISOCHRON AGE AND TECTONIC SETTING OF AMPHIBOLITES OF THE LONGSHAN GROUP IN EASTERN GANSU PROVINCE[J].Earth and Environment,2000,28(2):45-50. |
| |
| Authors: | Wu Maobing Fu Bihong Liu Chunyan |
| |
| Abstract: | Geological and geochemical characteristics of amphibolites of the Longshan Group in eastern GansuProvince show that there are two kinds of amphibolites with Sm-Nd isochron ages of 983 ±22Ma and 756 ±97Ma respetively, which were derived from magma sources similar to the MORB-type mantle. The information about trace elements and REE provides similar evidence. We also come to the conclusion that the original rocks of amphiboites were diabase dikes or veins, and they were proclucts of rift magmatism during800 ~ 1000Ma (Jinning Movement), and the rift is of considerable scale with an expanding rate of 2 ~ 5cm/a. |
| |
| Keywords: | Longshan Group amphibolite Sm-Nd isochron age geochemistry tectonic setting eastern Gansu Province |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
|
