华北地台东部古生代与新生代岩石圈地幔特征及其演化

Palaeozoic diamond-and xenolith-bearing kimberlites and Cenozoic xeoolith-bearing basalts, erupted in the eastern part of the North China Block (NCB), provide excellent mantle probes for research on intraplate processes and the Phanerozoic evolution of the subcontinental lithospheric mantle (SCLM). In this study, the mineral inclusions in diamond and xenoliths from Mengyin (Shandong province) and Fuxian (Liaoning province) kimberlites were chosen for constraining the nature of Palaeozoic SCLM, while xenoliths from the Shanwang and Qixia basalts (in Shandong province) were chosen for constraining the natures of Cenozoic SCLM, Shanwang lies astride the Taneheng - Lujiang (Tanlu) fault zone, a major lithospheric fault in eastern China, and Qixia lies east, of the fault zone. Based on the research on the petrography of mantle xenoliths, petrochemistry, major and trace element geochemistry of mantle minerals, mantle heat state, combined with the modern geophysical data, it is concluded that the attenuation and replacement of the Palaeozoic SCLM by upwelling asthenospheric materials through thermal erosion and possibly delamination resulted in the formation of irregular-shaped hot bodies, mainly along weakness zones within the mantle. The Tanlu fault played an important role in the Cenozoic replacement of the pre-existing lithospheric mantle.