Chromium-zoning patterns in pyroxene from the economically significant Ni-Cu sulfide deposits at Nova-Bollinger (Western Australia) and Kevitsa (Northern Finland) were investigated using XRF mapping, automated mineralogy, and EPMA analyses. At Nova-Bollinger, complex Cr-zoning patterns are found widely throughout the cumulus orthopyroxene and clinopyroxene within the Lower Intrusion, a small chonolith that hosts the vast extent of the sulfide mineralisation. Cumulus pyroxenes with visible sector and abrupt zonation patterns have been found up to 150 m vertically away from the massive sulfide ore. Complex zoning patterns are observed throughout the Kevitsa intrusion, in the form of strong oscillatory zoning in cumulus clinopyroxene and sector zoning in idiomorphic orthopyroxene oikocrysts. Kevitsa pyroxenes show varying degrees of hydration, leading to epitaxial replacement by amphibole. Cr zonation is visible through the early stages of this alteration, with preservation enabled by the presence of Cr-rich epitaxial amphibole; however, the remnant zoning is lost as the amphibole alteration progresses. Results suggest that Cr zonation in pyroxene may be an effective indicator of dynamic recharged conduits and therefore an indicator of favourable conditions for metal enriched magmatic sulfide ore formation. Such indicators have significant vertical extent from the ore body and can survive partial alteration, which makes them a useful tool for prospectivity assessment of drilled intrusions. Furthermore, our data show that there is potential for complexly zoned pyroxene to be used as an ex-situ prospectivity indicator in glacial till.

使用 XRF 绘图、自动化矿物学和 EPMA 分析对来自 Nova-Bollinger（西澳大利亚）和 Kevitsa（芬兰北部）具有经济意义的镍铜硫化物矿床的辉石中的铬分带模式进行了研究。在 Nova-Bollinger，复杂的 Cr 分带模式广泛存在于下侵入岩内的积云斜方辉石和单斜辉石中，下侵入体是一个小型的硅藻土，拥有大范围的硫化物矿化体。在距离块状硫化物矿石垂直距离达 150 m 的地方发现了具有可见扇形和突变带状图案的积云辉石。在整个 Kevitsa 侵入体中观察到复杂的分带模式，其形式为积云单斜辉石中的强振荡分带和特质斜辉石卵晶中的扇形分带。 Kevitsa 辉石表现出不同程度的水合作用，导致角闪石外延取代。 Cr 分带在这种蚀变的早期阶段是可见的，由于富含 Cr 的外延角闪石的存在而得以保存；然而，随着角闪石蚀变的进展，残余分区消失了。结果表明，辉石中的铬分带可能是动态补给管道的有效指标，因此也是富金属岩浆硫化矿形成的有利条件的指标。这些指示器与矿体有很大的垂直范围，并且可以在部分蚀变后幸存下来，这使得它们成为钻探侵入体前景评估的有用工具。此外，我们的数据表明，复杂分区的辉石有可能被用作冰碛物的异位远景指标。