Sr and Nd isotope ratios and trace element concentrations in kimberlites from Shandong and Liaoning (China) and the Kimberley area (South Africa)

Abstract

Strontium-Neodymium isotopes and 28 elements for Kimberlites from China (Shandong and Liaoning) and from South Africa (Kimberley area) have been measured to estimate their chemical characteristics and magma sources. The εSr and eNd values for Chinese kimberlites were, respectively, +1.0 to +93.0 and -4.3 to +0.2. The isotopic signature for all Shandong samples revealed very similar to those of Group I kimberlites (South African samples), whereas the Liaoning samples were categorized as Transitional. Although primitive mantle-normalized trace element patterns of the mean values of Group I Shandong and South African samples all resembled those of other Group I kimberlites, their HREE concentrations differed slightly. Shandong samples were depleted in HREEs. Our model calculation demonstrated that the kimberlites would be produced by partial melting with degree of less than 1%. Furthermore, Shandong samples were possibly generated from source rock in which the mineral contents differed slightly (specifically the proportion of garnet) from those of other regions. Copyright © 2012 by The Geochemical Society of Japan.