Occurrence of a new sulphate mineral: Ca_7Na_3K(SO_4)_9 in the Emet borate deposits, western Anatolia (Turkey)

摘要

Emetite, a new sulphate mineral, Ca_7Na_3K(SO_4)_9, has been identified in two boreholes drilled in the Emet borate district (Miocene;western Anatolia, Turkey). The evaporitic succession in these boreholes is mainly formed of a glauberite-probertite alternation. The new mineral always appears as a diagenetic phase consisting of aggregates of tiny (from few gm to tens of gm) crystals that replace glauberite at the top of glauberite units. The replacement was caused by the interaction of glauberite with K-rich interstitial brines, which are more concentrated than those from which glauberite had precipitated.