The active continental margin arc basalt（CAB）occurred mainly in Andes, it is generally considered that CAB is same as island arc basalt（IAB） roughly and basically they are in flocks in many discrimination diagrams, but the degree of enriched LILE and depleted HFSE is different silightly. In this paper, showing that CAB is enriched in LILE, however it is not very obviously for Nb-Ta depletion. CAB is different from IAB in the latest big data discrimination diagrams, instead plotting in IAB region, CAB plots in the transition region between IAB and OIB. CAB retains lots of OIB traces, indicating that plate subduction is accompanied by the magma from the deep mantle, resulting the OIB traces in CAB. We also find that the back-arc basin basalt of the Andes arc occurs OIB traces, rather than MORB features. According to the idea of big data, this paper discusses the characteristics of CAB and compared with IAB and BAB preliminary, showing that CAB is significantly different from IAB and it has the characteristics of both IAB and OIB, but the deep understanding needs a further study in thefuture.
Li Yuqiong Zhang Qi Wang Jinrong Liu Xinyu Chen Wanfeng . Global active continental margin arc basalt （CAB）characteristics: Compared with island arc basalt （ IAB）and back-arc basin basalt （BAB）[J]. Chinese Journal of Geology, 2017, 52(3): 693-713.