摘要
利用基于经典地幔岩无水熔融理论基础上的稀土元素(REE)反演方法,讨论了渤海湾盆地济阳坳陷中新生代岩石圈动力学过程。火山岩稀土元素反演结果表明,地幔异常高温显然与大陆地幔热柱活动有关。地幔热柱上升的过程从中生代末开始一直持续到新生代孔店期,新近纪地幔热柱才下降。结合盆地构造沉降情况,利用经验公式计算了岩石圈的厚度,认为计算出来的岩浆源深度基本上代表了软流圈顶面深度,由于软流圈的上涌将导致岩石圈的减薄,因此,在中、新生代交界处及沙四段末的济阳运动之前岩石圈厚度是减薄的,在济阳运动与东营运动之间的Es3-Es2-1时期岩石圈厚度也是减薄的,从Eg期至今,岩石圈厚度总体上也是减薄的。
This paper presents a discussion of the dynamic process of Mz-Cz lilhosphere in Jiyang depression of Bohai Bay basin by using REE inversion method based on classical theory of water-free melting mantle rock. The result shows abnormal high temperature of mantle is closely related to activity of continental mantle thermal plume that ascends since late Mz till Cz (Ek) and descends since N. Also, it is proved by calculated magma original depth representing the depth of top of asthenosphere that the upwelling of asthenosphere takes place with the thinning of lithosphere, hence, the thickness of lithosphere in Mz-Cz interface and before Jiyang movement (Es3) assumes thinning trend, so do the litho-sphere thickness during Es3 to Dongying movement (Es2-1) and the overall lithosphere thickness since Eg to present.
出处
《新疆石油地质》
CAS
CSCD
2004年第4期365-368,共4页
Xinjiang Petroleum Geology
基金
国家973项目(G199043302)和教育部青年骨干教师基金(K000110A)共同资助
关键词
济阳坳陷
中生代
新生代
地幔
稀土元素
反演
Jiyang depression
Mesozoic
Cenozoic
mantJe
rare eaith element (REE)
inversion
