Coronitic textures in ferrogabbroids of the Elet’ozero complex (North Karelia, Russia): Evidence for the existence of an immiscible high-Fe melt

Аннотация

It is demonstrated that most subsolidus coronitic textures in ferrogabbroids of the Elet’ozero intrusive complex result from crystallization of drops of immiscible interstitial high-Fe melt scattered among cumulates and containing SiO₂, Ti, Al, Ca, Na, K, Ba, and volatiles (water, F, and Cl) as well. Fe–Ti oxides were the first crystal phases, whereas other components were incorporated in the surrounding concentrically zoned rims composed of olivine, phlogopite, and kaersutite–pargasite. Reactional rims at the boundaries between olivine and plagioclase and symplectitic pargasite–muscovite–scapolite rims around the clusters of olivine and Fe–Ti oxides are observed as well. Thus, the coronitic textures in ferrogabbroids of the Elet’ozero Complex provide the first evidence for the existence of an immiscible, relatively low-temperature high-Fe melt in the natural magmatic systems.