Ceochemistry Of Platinum Group Elements In Emei Igneous Rock Province

AbstractIn the paper, the contents of platinum group elements (PGE) in Emeishan basalt and the associated Xinjie layered intrusion and syenites were analyzed using neutron activation techniques after fire-assay preconcentration. In addition, the contents of major element, trace element, Cu, Ni and S were also analyzed using chemical analysis, neutron activation techniques, and atomic absorption techniques respectively. The article systematically studies the relationships among platinum group elements, between platinum group elements and compatible elements, incompatible elements and sulphides of Emei Igneous Rock Province through making figures using Grapher~ Surpher~ Excel and assembling analysis of statistics. At the same time, the geochemistry and the regularities that govern the enrichment of PGE during magmatic evolution are discussed, the petrogenesis of Emei Igneous Rock Province and the relationship between Xinjie layed intrusion and Emeishan basalts are deeply analyzed, and the partition coefficients of POE are qualitatively analyzed.It turns out as follows:(1)With the magmatic evolution, the contents of the platinum group elements in Emei Igneous Rock Province tend to decrease progressively and hence the platinum group elements differentiate during magmatic stage.(2)During magmatic stage, platinum group elements are compatible and the compatibility of IPGE exceeds that of PPGE.(3)The differentiation and enrichment of PGE during magmatic evolution are related to the character of itself and also enfluenced by sulphide to a great extent.(4)The relative partitioning patterns of Xinjie layed intrusion, Emeishan basalts, and syenites are all of the Pt-Pd enrichment type with a primary mantle-normalized pattern inclined steeply to the left, reflecting a differentiation character similar to that of ferrufinous ultrabasic rocks in Bushveld and Sudbury but distinct from that in konatiite and Alpine-type peridotite.(5)The Xinjie layed intrusion and Emeishan basalts are similar to each other in geochemical characteristics of the POE, suggesting, among other lines of geochemical evidences, that they were drived from a common basaltic magma, in other words, they are products of different stages of differentiation from a common magma.(6)The partition coefficients of POE are as follows:D0) DR~ >Di~> D~> DPd...