Mechanisms of Platinum-Group Element Enrichment and the Nature of the Hydrothermal System at the Babbitt Deposit, Duluth Complex, Minnesota

建议继续研究PGE和明尼苏达州德卢斯杂岩巴比特铜镍矿床的分布和成因。初步结果表明，在整个Babbitt基底带成矿过程中，Ir、Os、Ru、Rh和Re表现为相对不动的元素，其分布与原生岩浆作用有关。Pt和Pd表现出非常不同的行为，与Cu和S表现出较差的相关性，这是再活化的有力证据。在铜镍矿高品位区外，发现了一个空间偏移的PGE富集带，其特征为@34S值异常，且具有硫化物-氧化物矿物学特征。同步加速器x射线微探针研究揭示了高体积Pd样品中铜矿物中Pd的ppm含量，以及热液蚀变过程中产生的mackinawite中Pd的富集。通过对大块岩石和矿物化学、蚀变反应以及S、H、O同位素的详细研究，确定了pge富集带与其余基底带成矿作用之间的关系。将使用激光烧蚀-质谱法（@34S值）和同步加速器x射线荧光微探针技术（PGE值）对单个硫化物矿物进行微采样。化学和同位素测量的渐进变化。此外，还将研究外源流体对PGE定位的影响。

A continuation of research dealing with the distribution and genesis of PGE and the Babbitt Cu-Ni deposit, Duluth Complex Minnesota, is proposed. Our preliminary results indicate that throughout the basal zone mineralization at Babbitt, Ir, Os, Ru, Rh, and Re have behaved as relatively immobile elements, and their distribution is related to primary magmatic processes. Pt and Pd show very different behavior, exhibiting poor correlations with Cu and S, and strong evidence of remobilization. A PGE- enriched zone has been detected which is spatially removed from the area of highest grade Cu-Ni ore, and is characterized by anomalous @34S values, and sulfide-oxide mineralogy. Synchrotron X-ray microprobe studies reveal ppm quantities of Pd in copper minerals from high bulk Pd samples, and Pd-enrichment in mackinawite produced during hydrothermal alteration. Detailed studies of bulk rock and mineral chemistry, alteration reactions, and S, H, and O isotopes are proposed to delineate the relationship between the PGE-enriched zone and the remainder of basal zone mineralization. Microsampling of individual sulfide minerals will be pursued using laser ablation-mass spectrometry (@34S values) and synchrotron X-ray fluorescence microprobe techniques (PGE values). Progressive changes in the chemical and isotopic measurements. The possible involvement of an externally-derived fluid in PGE localization will also be investigated.