fergusite

The main rock types of the NNS Formation are psedoleucite phonolite formed in the 1st subcycle of eruption and hauyne phonolite in the 2nd subcycle, as well as minor phonolitic ignimbrite, rhyakkumulate, and trachyte;2.

1、娘娘山组火山岩主要岩石类型为假白榴石响岩及蓝方石响岩,另有少量响岩质熔结凝灰岩、熔结角砾岩和粗面岩等;2、两亚旋回火山岩碱质含量变化趋势不同,假白榴石响岩更富钾,而蓝方石响岩更富钠。