Metal Sources and Mechanisms of Enrichment for Cu-Ni-PGE Mineralization in Fe-Ti-Rich Gabbroic Rocks in the Duluth Complex, Minnesota

巴别金Cu-Ti-Ni- 杜卢斯杂岩体的铂族元素存款存在于铁中， 接触带附近的富钛辉长岩 与弗吉尼亚的变质沉积岩 阵 为了评估可能的金属来源， 计划进行Os和Pb同位素研究。 这两个同位素 系统将提供直接证据， 金属的地壳或地幔来源的重要性 金属富集的机制将通过追踪 伴随着分数的化学变化 结晶作用、地壳同化作用、岩浆补给作用， 岩浆混合 杜卢斯地壳硫的增加是 这被认为是造成这些差异的主要原因。 是富硫化物和贫硫化物之间的连续体，氧化物- 磷灰石岩石 由于化学相似性， 并与中国东部的富Fe-Ti-P岩石进行了对比研究。 魁北克的Urbain和Labrieville斜长岩杂岩体 计划好了 结果将有助于我们理解相似性 以及成矿作用在层状 侵入岩、次火山侵入岩和火山岩型 斜长岩及相关岩石。

Disseminated sulfide mineralization at the Babbitt Cu-Ti-Ni- PGE deposit of the Duluth Complex is found within iron-and titanium-rich gabbroic rocks that occur near the contact with metasedimentary rocks of the underlying Virginia Formation. In order to evaluate possible metal sources Re- Os and Pb isotopic studies are planned. These two isotopic systems will provide direct evidence as to the relative importance of crustal or mantle sources of metals Mechanisms of metal-enrichment will be evaluated by tracing chemical variations that accompany fractional crystallization, crustal assimilation, magma recharge, and magma mixing. The addition of crustal sulfur at Duluth is thought to be a prime reason for the differences in what may be a continuum between sulfide-rich and sulfide-poor, oxide- apatite rocks. Because of the chemical similarities a comparative study with Fe-Ti-P-rich rocks from the St. Urbain and Labrieville anorthosite complexes in Quebec is planned. Results will aid our understanding of similarities and differences between mineralization in layered intrusions, subvolcanic intrusives, and massif-type anorthosites and related rocks.