Science. 1986 Oct 10;234(4773):189-93. doi: 10.1126/science.234.4773.189.
A glassy fulgurite, formed recently on a morainal ridge in southeastern Michigan, contains micrometer- to centimeter-sized metallic globules rich in native silicon, which unmixed from a silica-rich liquid. The unusual character of these globules and their potential for elucidating conditions of fulgurite formation prompted further study. Thermodynamic calculations indicate that temperatures in excess of 2000 K and reducing conditions approaching those of the SiO(2)-Si buffer were needed to form the coexisting metallic and silicate liquids. The phases produced are among the most highly reduced naturally occurring materials known. Some occurrences of other highly reduced minerals may also be due to lightning strike reduction. Extreme reduction and volatilization may also occur during high-temperature events such as lightning strikes in presolar nebulae and impacts of extraterrestrial bodies. As a result of scavenging of platinum-group elements by highly reduced metallic liquids, geochemical anomalies associated with the Cretaceous-Tertiary boundary may have a significant terrestrial component even if produced through bolide impact.
一个玻璃质的陨石坑，最近在密歇根州东南部的一个冰碛脊上形成，含有富含原生硅的微米级到厘米级大小的金属小球，这些小球与富硅液体混合。这些小球的不寻常性质及其对阐明陨石坑形成条件的潜在作用促使进行了进一步的研究。热力学计算表明，需要超过 2000 K 的温度和接近 SiO(2)-Si 缓冲的还原条件才能形成共存的金属和硅酸盐液体。所产生的相是已知的最具还原性质的天然物质之一。其他一些高度还原的矿物的出现也可能是由于雷击还原。在高温事件（如太阳星云中的雷击和外星体的撞击）中，也可能发生极端还原和挥发。由于高度还原的金属液体对铂族元素的清除，与白垩纪-第三纪边界相关的地球化学异常即使是通过陨石撞击产生的，也可能具有重要的陆地成分。
