North China Craton

Re-Os data for peridotite xenoliths erupted by Paleozoic kimberlites of the North China craton indicate the presence of refractory, chemically buoyant Archean lithospheric mantle beneath the craton at that time. Younger, post-Archean Re-Os model ages obtained from peridotite xenoliths erupted by Tertiary alkali basalts in the same craton indicate that the deeper section of the cratonic keel was replaced by more fertile lithospheric mantle sometime after the Palaeozoic (Gao et al, 2002). 

Gao S., Rudnick R. L., Carlson R. W., McDonough W. F., and Liu Y.-S. (2002) Re-Os evidence for replacement of ancient mantle lithosphere beneath the North China craton. Earth Planet. Sci. Lett. 198, 307-322. 

The Wutai-Jining Zone is suggested to be an exposed cross-section through the Archean North China craton (Kern et al., 1996). Rocks from this exposure equilibrated at depths of up to —30 km, thus sampling middle and uppermost lower cmst, but leaving the lowermost 10 km of crust unexposed (Kern et al., 1996). Like the previously described cross-sections, felsic gneisses dominate... 

Gao S., Kem H., Liu Y. S., Jin S. Y., Popp T., Jin Z. M., Feng J. L., Sun M., and Zhao Z. B. (2000) Measured and calculated seismic velocities and densities for granulites from xenolith occurrences and adjacent exposed lower cmstal sections a comparative study from the North China craton. J. Geophys. Res. Solid Earth 105(B8), 18965-18976. 

Shaw et al., 1986 Gupta et al, 1991 Jaupart et al., 1998 Gao et al., 1998). The value of Shaw et al. (1986) for the Canadian Shield is not consistent with the heat flow data. Thus, one may not apply one estimate for one province to another province. A further difficulty is that the crustal thickness varies significantly. For example, the crust of the North China craton is thinner than average (—35 km Gao et al., 1998). 

The growing consensus that ancient crust is always underlain by ancient lithospheric mantle has been challenged recently by Wu et al. (2003). These authors report an unusual absence of xenoliths with Archaean ages beneath the Archaean North China Craton. They propose that in some cases, therefore, ancient subcontinental mantle can be removed from beneath ancient continental crust by delamination - a process which has previously been postulated but never demonstrated. The subject of mantle delamination is discussed more fully in Chapter 5, Section 5.5.2. 

In contrast, deep crustal rocks found in metamorphic belts, granulites, are much more varied in composition and include both felsic and mafic varieties (Rollinson St Blenkinsop, 1995). This is consistent with a recent study in the North China Craton which showed that there the lower crust can be divided into two layers - an upper lower crust with velocities between 6.7 and 6.8 km/sec and a lowermost crust, with velocities between 7.0 and... 

Kusky, T.M., Li, J.-H., and Tucker, R.D., 2001. The Archaean Dongwanzi ophiolite complex, north China Craton 2.505 billion-year-old oceanic crust and mantle. Science, 292, 1142-5. 

Bohai Bay Basin is a superimposed basin in Mesozoic and Cenozoic that developed on the basis of North China Craton (ancient crystalline basement), which was composed of a series of NNE and NE directive depressions and uplifts among. They are, from north-west to south-east, Jizhong depres-... 

Zhang, S.H., Zhao, Y., Yang, Z.Y., He, Z.F., and Wu, H. (2009) The 1.35Ga diabase sills from the northern North China Craton implications for breakup of the Columbia (Nuna) supercontment. Earth Planet. Sci. Lett., 288 (3 ), 588-600. 

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