Boyd F R, Gurney J J
Science. 1986 Apr 25;232(4749):472-7. doi: 10.1126/science.232.4749.472.
Data and inferences drawn from studies of diamond inclusions, xenocrysts, and xenoliths in the kimberlites of southern Africa are combined to characterize the structure of that portion of the Kaapvaal craton that lies within the mantle. The craton has a root composed in large part of peridotites that are strongly depleted in basaltic components. The asthenosphere boundary shelves from depths of 170 to 190 kilometers beneath the craton to approximately 140 kilometers beneath the mobile belts bordering the craton on the south and west. The root formed earlier than 3 billion years ago, and at that time ambient temperatures in it were 900 degrees to 1200 degrees C; these temperatures are near those estimated from data for xenoliths erupted in the Late Cretaceous or from present-day heat-flow measurements. Many of the diamonds in southern Africa are believed to have crystallized in this root in Archean time and were xenocrysts in the kimberlites that brought them to the surface.
来自对南非金伯利岩中钻石包裹体、捕虏晶和捕虏岩的研究数据及推断结果被整合起来，以描绘位于地幔中的卡普瓦尔克拉通该部分的结构。克拉通有一个主要由玄武岩成分严重亏损的橄榄岩组成的根。软流圈边界从克拉通下方170至190千米深处，向南和向西延伸至与克拉通接壤的活动带下方约140千米处。这个根形成于30亿年前之前，当时其内部环境温度为900摄氏度至1200摄氏度；这些温度接近根据晚白垩世喷发的捕虏岩数据或现今热流测量估算出的温度。据信，南非的许多钻石是在太古代时期在这个根中结晶的，并且是将它们带到地表的金伯利岩中的捕虏晶。
