首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Thermal anomalies and magmatism due to lithospheric doubling and shifting
Authors:NJ Vlaar
Institution:Vening Meinesz Laboratory, Instituut voor Aardwetenschappen, University of Utrecht, Budapestlaan 4, 3584 CD Utrecht The Netherlands
Abstract:We present some thermal and magmatic consequences of the processes of lithospheric doubling and lithospheric shifting.Lithospheric doubling concerns the obduction of a cold continental or old oceanic lithospheric plate over a young and hot oceanic lithosphere/upper mantle system, including an oceanic ridge.Lithospheric shifting concerns the translation and rotation of a lithospheric plate relative to the upper mantle.In both cases the resulting thermal state of the upper mantle below the obducting or shifting lithosphere may be perturbed relative to a “normal” continental or oceanic geothermal situation.The perturbed geothermal state gives rise to a density inversion at depth and thus induces a vertical gravitational instability which favours magmatism.We speculate about the magmatic consequences of this situation and infer that in the case of lithospheric doubling our model may account for the petrology and geochemistry of the resulting magma.The original layering and composition of the overridden young oceanic lithosphere may strongly influence magmatic processes.We dwell shortly on the genesis of kimberlites within the framework of our lithospheric doubling model and on magmatism in general. Lithospheric recycling is inherent to the mechanism of lithospheric doubling.
Keywords:
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号