Abstract

Peridotites of an unusual orbicular structure, attributed to the impregnated type of rocks, were found in ophiolites of the Voikar massif (Polar Urals). Orbicules in these rocks are composed of a secondary clinochlore–diopside aggregate containing grains of primary clinopyroxene and pargasite. The morphology and composition of orbicules make it possible to attribute them to segregations (globules) of the melt in the olivine matrix of peridotites that have experienced partial crystallization in situ. According to geochemical modeling results, these melts had characteristics transitional to boninites, corresponding to the suprasubduction conditions. The formation of orbicular peridotites was associated with blocking intergranular channels of the percolating basaltic melts.

中文翻译：

---

极地乌拉尔的圆形橄榄岩：蛇绿岩中岩浆浸渍的新证据

摘要

在 Voikar 地块（极地乌拉尔）的蛇绿​​岩中发现了具有不寻常的圆形结构的橄榄岩，归因于浸渍类型的岩石。这些岩石中的球体由次生斜绿石-透辉石聚集体组成，其中包含初级斜辉石和细长辉石颗粒。球状体的形态和组成使其有可能归因于橄榄岩橄榄岩基质中熔体的偏析（球体），这些橄榄岩在原位经历了部分结晶。根据地球化学模拟结果，这些熔体具有过渡到boninites的特征，对应于超俯冲条件。球状橄榄岩的形成与渗流玄武岩熔体的粒间通道的阻塞有关。