北祁连阿柔地区奥陶纪火山岩岩石学特征及其喷发旋回研究

Study on Petrological Characteristics and Eruption Cycles of Ordovician Volcanic Rocks in Arou Area of North Qilian Mountain

北祁连阿柔地区奥陶纪火山岩分布广泛,发育在早奥陶世阴沟组和晚奥陶世抠门子组。对北祁连阿柔地区奥陶纪火山岩分布特征和岩石学特征进行了研究,划分了3类火山岩岩相:爆发相、喷溢相、喷发-沉积相。并划分了2个火山岩喷发旋回:阴沟旋回和扣门子旋回。揭示了阿柔地区祁连洋(裂谷)演化特征,对北祁连地区火山岩区域对比及火山机构恢复具有一定的指导意义。

Ordovician volcanic rocks are widely distributed in Arou area of north Qilian mountain. It is developed in early Ordovician Yingou group and late Ordovician Koumenzi group. Distribution characteristics and petrological characteristics of Ordovician volcanic rocks in Arou area of north Qilian mountain have been studied. Three types of volcanic lithofaeies have been divided, they are eruption facies, eruption facies and eruption- sedimentary facies, and two volcanic eruption cycles as Yingour cycle and Koumenzi cycle have been divided as well. Qilian oceanic （rift） evolution characteristics in Arou area of north Qilian mountain has been revealed. It has certain significance for guiding the contrast between volcanic region of north Qilian mountain and recovery of volcanic body.