Petrogenetic evaluation of the Laohutai basalts from North China Craton: Melting of a two-component source during lithospheric thinning in the late Cretaceous–early Cenozoic

Geochemistry of Cenozoic basalts from the Bohai Bay Basin: Implications for a heterogeneous mantle source and lithospheric evolution beneath the eastern North China Craton

“…Overall, the Jiyang Sag basalts are characterized by slightly depleted highly incompatible elements (e.g., Ba, Th, U and LREE) relative to Nb, positive Eu and Sr anomalies in the primitive mantle-normalized multi-element diagram (Fig. 6b) and moderately depleted Sr-Nd-Hf isotopes, which is consistent with the existence of oceanic crust in the magma source (Hofmann, 2004;Kuang et al, 2012;Stracke et al, 2005;Tang et al, 2012Tang et al, , 2013.…”

“…Several models have been proposed for the origin of enriched component in the mantle source, such as delaminated lower continental crust (Chen et al, 2009;Liu et al, 2008;Zeng et al, 2011), subducted oceanic crust and sediment (Hong et al, 2013;Kuang et al, 2012;Tang et al, 2012Tang et al, , 2013 and long-term metasomatized lithospheric mantle (Niu and O'Hara, 2003;Z. Xu et al, 2012;Zhang et al, 2009).…”

“…La/Yb and Dy/Yb ratios will be strongly fractionated by low-degree partial melting (b10%) of garnet peridotite (Xu, 2001). In contrast, La/Yb is only slightly fractionated and Dy/Yb is nearly unfractionated during the melting of spinel peridotite (e.g., Huang et al, 2013;Kuang et al, 2012;Shaw et al, 2003;Thirlwall et al, 1994).…”

“…The compositional variation of mantle-derived rocks in time and space can help reveal the nature of lithospheric evolution (e.g., Bianchini et al, 2008;Gao et al, 2008;Griffin et al, 1992Griffin et al, , 1998Guo et al, 2001;Hong et al, 2013;Huang et al, 2012;Kuang et al, 2012;Liu et al, 2008;Martins et al, 2008;Menzies et al, 1993Menzies et al, , 2007Thirlwall et al, 1994;Xu et al, 2004b;Yang and Li, 2008;Zhang et al, 2002). Cenozoic lithospheric evolution beneath the eastern NCC has not been well recognized in the previous studies, primarily because: (1) Seismic tomography revealed the thinnest lithosphere beneath the Bohai Bay Basin, the largest Cenozoic basin in the eastern NCC (Chen, 2010;Tian et al, 2009), but few geochemical and age data are available on basalts from the Bohai Bay Basin because of limited exposure (Xu et al, 2004a); (2) Most studies have focused on the magmatism in the Early Cretaceous (e.g., Gao et al, 2008;Guo et al, 2001;Huang et al, 2012;Xu et al, 2004b;Yang and Li, 2008;Zhang et al, 2002) and Late Cenozoic (b23 Ma) (e.g., Chen et al, 2007;Fan and Hooper, 1991;Song et al, 1990;Tang et al, 2006;Xu et al, 2004aXu et al, , 2005; Y.G.…”

Olivine and melt inclusion chemical constraints on the source of intracontinental basalts from the eastern North China Craton: Discrimination of contributions from the subducted Pacific slab

“…1). The sources of northeastern China basalts have been described as mixing between an isotopically depleted mantle and EM1 mantle (e.g., Liu et al, 2008;Chen et al, 2009;Zeng et al, 2010;Kuang et al, 2012;Xu et al, 2012a,b;Hong et al, 2013;Li et al, 2014), while those of southeastern China basalts have been characterized as mixing between a depleted mantle and EM2 mantle (e.g., Zou et al, 2000;Huang et al, 2013). Therefore, it is unreasonable to simply attribute the enriched components of eastern China basalts to the stagnant Pacific slab in the MTZ.…”