Radiometric Ages (Rb-Sr, Sm-Nd, U-Pb) and REE Geochemistry of Archaean Granulite Gneisses from Eastern Hebei Province, China

Neoarchean to Paleoproterozoic continental evolution and tectonic history of the North China Craton: a review

“…The ultramaficmafic rocks with high REE abundance show different geochemical characteristics, ranging from MORB to komatiite. Furthermore, supracrustal rocks, gabbros and mafic dykes yield different Sm -Nd whole rock isochron ages; at , 2.7 Ga (Li, 1999), , 2.5 Ga (Jahn and Zhang, 1984) and , 1.8 Ga (Li, 1999), respectively. Other maficultramafic associations in the NCC have been studied in detail to test if ophiolites may be represented, including the metamorphosed mafic rocks in the Yanlingguan greenstone belt, amphibolites with apparent pillow-lava texture in the Qinglong greenstone belt and ultramafic -mafic rock associations in the Jiangouhe complex of northwest Hebei.…”

“…2) and near Tiejiashan in Liaoning Province ( Fig. 1) (Liu et al, 1994;Huang et al, 1983;Jahn and Zhang, 1984). The main supracrustal rocks are amphibolites, fuchsite quartzites, banded magnetite quartzites, diopsidites and serpentinized marbles.…”

Cratonization and the Ancient North China Continent: A summary and review

“…1950 to 3800 Ma and are mostly in the range of 2600-3000 Ma with a peak of 2820 Ma [10]. The study on early Precambrian TTG gneisses and volcanic rocks in the world shows that the uppermost period of global crustal growth is 2.7-2.8 Ga, and the dominant crustal rocks are felsic orthogneisses with high Na content, and secondary mafic-ultramafic volcanic/plutonic rocks [21][22][23][24]. Therefore, this crustal accretion has been proposed to be attributed to a super mantle plume event [15,25,26], and the early large-scale crustal accretion at ca.…”

The Caraguataí syenitic suite, a ca. 2.7Ga-old alkaline magmatism (petrology, geochemistry and U–Pb zircon ages). Southern Gavião block (São Francisco Craton), Brazil

“…The means to reach the protoliths is to define the contents of the chemical elements and their characteristics in orthogneisses and compare them with other plutons of similar composition of other regions, which have not undergone metamorphism. Such procedure has been used for many years to the petrogenetic characterization of orthogneiss protoliths (Waever and Tarney, 1980;Condie and Allen, 1984;Jahn and Zhang, 1984;Martin et al, 1997Martin et al, , 2005, among others). The analytical data for the Caraguataí orthogneisses were compared with those for several worldly known massifs of similar composition, e.g.…”