ABSTRACT
The well preserved 2.3–2.4 Ga Kuandian Complex is located in a Proterozoic mobile belt bounded by Archean blocks of the northeastern Sino-Korea Craton. The Complex is mainly composed of amphibolites, gneisses, and layered granites. Geochemical studies show that the protoliths of the complex are associations of a bimodal magmatic suite with Sm values between 0.26 and 1.94. The Kuandian amphibolites are depleted in Nb, Ta, and Ti, and enriched in K, Rb, and Pb, with pronounced depletion of Sr relative to Nd and Pb, Nb/La ratios are lower than 1 (0.3–0.8). The trace element patterns of the amphibolites are similar to those of continental flood basalts formed by the rifting of Gondwana, such as the Karoo and Tasmania basalts, featuring crustal contamination. Trace element modeling indicates that Kuandian gneisses and granite could be produced by extensive fractional crystallization from a magma with a composition similar to those of the amphibolites. This study indicates that the evolution of the Sino-Korean Craton is in contrast with that of many other Precambrian continents, e.g. North America, Europe, and Australia, in terms of vigorous magmatic activities between 2.3 and 2.4 Ga in the Sino-Korea Craton.
