A petrochemical analysis was undertaken of peridotitic xenoliths in volcanic rocks that erupted from the Paleozoic to the Cenozoic within the eastern part of the North China craton, and the peridotites as tectonic intrusive in the Early Mesozoic from the Sulu orogen. The results show that the cratonic mantle, which was refractory and existed when the kimberlites intruded in the Paleozoic, had almost been replaced by the newly accreted fertile lithospheric mantle during the Mesozoic-Cenozoic. The erosion, metasomatism and intermingling caused by the accreted asthenospheric material acting on the craton mantle along the weak zone and deep fault (such as the Tanlu fault) in the existing lithosphere resulted in the lithosphere thinning at a larger scale of 100 Ma ago (but later than 178 Ma). The largest thinning would be in the Eogene. The upwelling asthenospheric material transformed into accreted lithospheric mantle due to the asthenospheric temperature falling in the Neogene (leading to relatively slight lithospheric incrassation), and finally accomplished mantle replacement. The peridotitic body in the Sulu orogen represents the products spread from the modified cratonic lithospheric mantle.
|Number of pages||8|
|Journal||Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences|
|Publication status||Published - Jan 2006|
- Eastern North China
- Mantle replacement