| Summary: | The oldest nuclei of the Sinokorean Craton are the 3.5 Ga
amphibolites and grey gneisses of the Qianxi Complex and the
≥3.0 Ga Qingyuan Complex that may extend to the Anshan area to
include the ≥3.O Ga Tiejiashan and Lishan granites. Other highgrade
metamorphic complexes of the Sinokorean Craton are mostly
between 2.7 and 2.8 Ga in age - the Anshan, Longgang, Jianping,
Taishan, Jiaodong, and Taihua complexes. The high-grade Fuping
Complex formed about 2.6 Ga ago in an environment like a modern
island arc: it is not one of the earliest nuclei. The medium—
grade Wutai Complex formed by 2.5 Ga ago, mostly in a tectonic
setting similar to that of Fuping Complex, with the exception
that one volcanic cycle formed in an environment like a modern
MOR and one unit formed in an environment transitional between
modern within-plate and plate margin settings. There is no
evidence for continental crust older than 2.6 Ga in the
Wutaishan and Taihangshan regions. The Sm-Nd systems for
metabasaltic rocks in the Wutaishan and Taihangshan region, are
all significantly disturbed, in contrast with the undisturbed
Sm-Nd system reported for rocks older than 2.6 Ga in the
Sinokorean Craton.
High-grade rocks of the Sanggan and Dengfeng complexes,
and some granulites in the Qianxi Complex are ≥2.5 Ga in age.
Available Nd isotopic data show that rocks older than 2.5 Ga in
the Sinokorean Craton are derived from a mantle source more
depleted than that defined by DePaolo’s depleted mantle
evolution curve. Granitic magmatism peaked 2.5 Ga ago in the
Sinokorean Craton, affecting all the previously formed rocks.
Nd isotopic data show significant crustal involvement in
formation of some ~2.5 Ga granites in the Sinokorean Craton.
Early Proterozoic mafic volcanic rocks of the 2.3 to 2.4
Ga Kuandian Complex in Liaoning Province and the Hutuo Complex
in Shanxi Province, formed in a intra—continental environment.
Kuandian granites have an anorogenic granite character. The
early Proterozoic mantle magma source in the eastern Liaoning
Province is less depleted than the mantle of DePaolo’s (1981)
average mantle evolution curve. This can be explained by
contamination of Archean basement or derivation from a different
mantle source.
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