Abstract Pillow lavas are an abundant morphological lava type both on Earth and on some extraterrestrial bodies. We examine pillows from Kambalda (Western Australia) komatiites, that uniquely preserve pillow necks, inter-pillow cavities, and internal crusts. Our study is the first description of true pillows from an Archaean high-MgO (~31%) komatiite. Their size ranges from 0.5 to 5 cm and most have equal vertical and horizontal axes. Due to very low melt viscosities (~0.01 – 0.1 Pa s), these komatiite pillows are one to two orders of magnitude smaller than modern basaltic counterparts. True high-MgO komatiites, such as those at Kambalda, require a low flow rate, potentially found on distal flow edges. Such low flow rates are in conflict with the high flow velocities generally assumed for komatiites, and hence explains the rarity of komatiite pillow lavas.

中文翻译：

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稀有高镁科马提岩枕状熔岩的质地、形成和动力学

摘要 枕状熔岩是地球和一些地外天体上丰富的形态熔岩类型。我们研究了来自 Kambalda（西澳大利亚）科马提岩的枕头，它们独特地保留了枕颈、枕间空腔和内部结壳。我们的研究首次描述了来自太古代高 MgO (~31%) 科马提岩的真正枕头。它们的大小范围从 0.5 到 5 厘米，大多数具有相等的纵轴和横轴。由于熔体粘度非常低（~0.01 – 0.1 Pa s），这些科马提岩枕比现代玄武岩枕小一到两个数量级。真正的高 MgO 科马提岩，例如 Kambalda 的那些，需要低流速，可能在远端流动边缘发现。如此低的流速与科马提岩通常假设的高流速相冲突，