Early Cretaceous low-Mg adakitic granites from the Dabie orogen, eastern China: Petrogenesis and implications for destruction of the over-thickened lower continental crust

Petrogenesis of mafic dykes and high-Mg adakitic enclaves in the Late Mesozoic Fangshan low-Mg adakitic pluton, North China Craton

“…6C). High-pressure (1.0-4.0 GPa) dehydration melting of metabasaltic rocks and eclogites can generate high-K granitic melts (see Xu et al (2007Xu et al ( , 2012a and Wang et al (2007) for detailed discussion). Isotopically, they have higher values of ( 87 Sr/ 86 Sr) (t=135Ma) ratios (0.7051-0.7055), lower ( 143 Nd/ 144 Nd) (t=135Ma) ratios (0.5115-0.5118) and e Nd (t = 135 Ma) (À13.7 to À17.9) (Cai et al, 2005;Zhang et al, 2006) than that of slab melt defined by Defant and Drummond (1990).…”

Petrogenesis of the early Cretaceous volcanic rocks in the North Huaiyang tectono-magmatic unit of the Dabie Orogen, eastern China: Implications for crust–mantle interaction

“…As illustrated in Fig. 8, the zircon e Hf (t) values of the Jingangtai volcanic rocks match with those of granites in the Dabie Orogen Zhang et al, 2010a;Xu et al, 2013) and Early Cretaceous intermediat-mafic rocks in the Dabie Orogen (Xu et al, 2012), indicating a genetic relationship between them.…”

Crustal thickening and uplift of the Tibetan Plateau inferred from receiver function analysis

“…If the lower crust has been subjected to high pressures in a convergent orogen, this would lead to the formation of eclogites, creating a density instability (Elkins-Tanton, 2005;Xu et al, 2012;Zhang et al, 2012a,b,c;Gao et al, 2004), and triggering lower crustal delamination or the convective removal of the eclogitic lower crust (Kay and Kay, 1993;Vlaar et al, 1994;van Thienen et al, 2004). Several seismic studies have illustrated abnormally low velocities for the Tibetan lower crust (Sapin and Hirn, 1997;Cotte et al, 1999;Zhao et al, 1996), precluding the presence of any eclogite (Schulte-Pelkum et al, 2005), which suggests that the lower crust might have been delaminated.…”