Isotopic (Sm–Nd) and Geochemical (Nb/Y–Zr/Y) Systematics of the Sikhote-Alin Basic-Hyperbasic Complexes

Abstract

The paper demonstrates the possibility of application of the 143Nd/144Nd–Sm/Nd and Nb/Y–Zr/Y diagrams to systematics of basic–ultrabasic complexes of different age: Paleozoic Kalinovsky, Cambrian Sergeevsky and Vladimiro-Aleksandrovsky, and Jurassic and Paleocene ones. The position of data points of the Kalinovsky, Sergeevsky, and Vladimiro-Aleksandrovsky complexes in the diagrams indicates their derivation from a primitive mantle-type (BSE) source, the derivatives of which are frequently associated with Cu, Ni, Co, and PGE mineralization. The position of data points of metabasic rocks of the Avdokimovsky complex and peridotite rocks of the Dalny Kut massif in these diagrams suggests that they have originated from depleted mantle and are promising for the discovery of PGE-bearing chromite mineralization. Data points of Paleocene explosive structures of Sikhote-Alin in the Nb/Y–Zr/Y diagram fall on the trend of recycled crust as a source. This explains the alkaline (to subalkaline) type of magmatism and the high gas saturation of magmas. The explosive structures resemble lamproite pipes, while their rocks are geochemically and mineralogically close both to lamproites and kimberlites.