Full-Text Search:
Home|About CNKI|User Service|中文
Add to Favorite Get Latest Update

General Features and Origin of Cenozoic Basalts from Chifeng Region,North China

HAN Baofu\ WANG Shiguang (Department of Geology,Peking University,Beijing,100871)  
The Cenozoic basalt from Chifeng region,North China,are characterized by Al 2O 3=12.51%~14.42%,Na 2OK 2O,and TiO 22.00%.They are continental flood basalt,produced by fissure type volcanism in the Miocene.The basalts chemically belong to the tholeiitic series and were derived from asthenospheric source regions.Two processes would be responsible for the generation of the basalts.The basaltic magma was first generated by partial melting of peridotites in the mantle,followed by fractionation of olivine from the magma.The magma formed at depth of the mantle ascended into a chamber within the continental crust,where it could cease moving up further and concentrated to some extent.It was in the chamber that some of olivine crystallized early was fractionated from the magma.Then,the remaining olivine would reacted with the magma,resulting in the development of clinopyroxene rim around olivine.It is suggested that the fractional crystallization of olivine from the magma is probably a common process to the formation of continental flood basalts.
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©CNKI All Rights Reserved