Das Verhalten von Platingruppenelementen während oberkrustaler in situ - Fraktionierung in Magmen der Ferrar Plateaubasaltprovinz, Antarktis

我们前期研究的费拉尔大火成岩省浅层侵入岩的PGE模式是相对于原始地幔的分馏，R和Pd在Ir和Ru(IPGE)上强烈富集，与岩浆分异程度相关。相容的IPGE像Ni一样被均匀亏损，亲铜元素在进一步分异过程中被均匀地富集，而R和Pd要么表现为富集，要么表现为亏损。在MORB、洋岛或泛滥玄武岩环境中，铜与铜的耦合富集趋势在任何其他火山田中都是未知的。基于现有的岩石化学和岩石学数据，我们无法推断出可以解释铂和钯在分异过程中相容或不相容行为的物理化学差异。在这里申请的项目中，我们将检验这一模型，即在原地分异过程中浅层上地壳岩浆体的内部物理化学变化是造成观察到的分馏模式的原因。除了全岩分析外，我们还将确定含PGE的矿物相。这些研究将只对已经从窗台和Dufek入侵中采集的样本进行，这些样本是由Woerner，Goettingen教授和Mukasa教授提供的。来自美国密歇根州，由申请人在2005/06年度GANOVEX IX探险期间拍摄。该项目的目的是在两个IPY项目的框架内启动对Dufek侵入体中PGE内部地层学的详细调查(Meschede等人。2004年，Mukasa 2004)。

The PGE-patterns of shallow intrusive rocks of the Ferrar Large Igneous Province studied within our previous project are fractionated with respect to primitive mantle, R and Pd being strongly enriched over Ir and Ru (IPGE), correlating with the degree of magma differentiation. While the compatible IPGE are uniformly depleted like Ni and the chalcophile element Cu is uniformly enriched with further differentiation, R and Pd either exhibit enrichment or depletion. The coupled enrichment trend with Cu is unknown from any other volcanic field in MORB-, ocean island- or flood basalt environments. Based on the existing data set on rock chemistry and petrography we are unable to deduce physicochemical differences that may explain the compatible or incompatible behaviour of Pt and Pd during differentiation. Within the project applied here for, we will test the model that internal physicochemical variations in shallow upper crustal magma bodys during in situ - differentiation are responsible for the observed fractionation patterns. Aside from whole-rock analyses we will identify the PGE-bearing mineral phases. These studies will be performed exclusively on already taken samples from sills and the Dufek Intrusion provided by Prof. Woerner, Goettingen, and Prof. Mukasa, Univ. of Michigan, USA and taken by the applicant during the expedition GANOVEX IX in 2005/06. The project is intended to be the initiation of detailed investigations on the PGE internal stratigraphy in the Dufek Intrusion within the framework of two IPY-projects (MESCHEDE et al. 2004, MUKASA 2004).