大兴安岭北段塔木兰沟组玄武岩地球化学及构造背景

详细信息

收稿日期: 2003-10-05

修回日期: 2004-02-23

刊出日期: 2005-06-30

GEOCHEMICAL CHARACTERISTICS AND TECTONIC BACKGROUND OF BASALT FROM TAMULANGOU FORMATION IN NORTHERN DAXINGANLING

Received Date: 05 October 2003

Revised Date: 23 February 2004

Publish Date: 30 June 2005

摘要: 通过对大兴安岭北段塔木兰沟组玄武岩岩石学、地球化学及其形成的大地构造环境的综合研究发现,塔木兰沟组玄武岩具有拉斑玄武岩和碱性玄武岩的双重特征,Na2O-22O;Eu无异常,La/Yb=35.7(平均);富集Ba、Sr、K,亏损Nb.岩浆的形成可能与裂谷作用有关.在这一构造-热事件中,推测该裂谷在上黑龙江地区陆壳减薄最大,呼中地区岩石圈减薄最大,根河地区陆壳、岩石圈减薄均较小.
- 玄武岩 /
- 裂谷作用 /
- 塔木兰沟组 /
- 大兴安岭北段
Abstract: Study on the petrology, geochemistry and tectonic setting of the basalt from Tamulangou formation indicates that the basic volcanic rocks are geochemically similar to both tholeiitic basalt and alkali basalt, with Na2O-22O, nonegative Eu anomaly, La/Yb=35.7, rich Ba, Sr and K, and deficient Nb. The magma is probably generated by rifting. In such a thermal-tectonic event, it is speculated that the crust in Shangheilongjiang area and the lithosphere in Huzhong area were thinned greatly; while the lithosphere and the crust in Genhe area were slightly thinned.
- basalt /
- rifting /
- Tamulangou formation /
- Northen Daxinganling