Metasomatic Processes and Platinum Group Element Deposits in Layered Intrusions

9316129 Mathez大型层状镁铁质复合体很重要，因为它们包含了火成岩岩石学中基本过程的证据，并且因为其中几个含有各种金属的经济矿床，包括铂族元素（PGE）。 这个项目解决的基本问题是什么样的作用后积云，岩浆过程，特别是交代作用，在形成富含铂族元素的地平线。 为了调查这个问题，将进行两项相关研究。 第一个涉及到微量元素含量的辉石和其他主要阶段的Merensky礁和附近的岩石在阿托克地区，东北布什维尔德复杂的详细研究。 第二项研究涉及大堤坝富含PGE的地平线。 该层位被称为MSZ，显示出特征性的地球化学地层剖面，其中发现Ni、Cu、S和Au的最大浓度在地层中比Pt、Pd和其他PGE的最大浓度高约15至30 cm。 将寻求辉石中亲硫元素和不相容元素含量之间的关系，这也将由离子探针测定。 Se/S、As/S和Te/S比值有助于区分硫化物是以堆积作用为主还是以交代作用为主。

9316129 Mathez The large layered mafic complexes are important because they contain evidence for fundamental processes in igneous petrology and because several contain economic deposits of various metals, including the platinum group elements (PGEs). The essential question addressed by this project is what is the role of post-cumulus, magmatic processes, in particular metasomatism, in the formation of PGE-rich horizons. In order to investigate this question, two related studies will be conducted. The first involves a detailed study of trace element contents of pyroxene and other major phases of the Merensky reef and adjacent rocks in the Atok area, northeast Bushveld Complex. A second study involves the PGE-rich horizon of the Great Dyke. The horizon, which is known as the MSZ, exhibits a characteristic geochemical stratigraphic profile whereby the maximum concentrations of Ni, Cu, S and Au are found approximately 15 to 30 cm higher in the stratigraphy than the maximum concentrations of Pt, Pd and the other PGEs. A relationship will be sought between the profiles for the chalcophile elements and incompatible element contents of pyroxene, which again will be determined by ion probe. Se/S, As/S and Te/S ratios may help to distinguish whether the sulfides were concentrated by mainly cumulate or metasomatic processes.