Abstract: Yanshan and Gaoshan,two Holocene volcanoes in the Halaha River and Chaoer River volcanic cluster,are different from volcanoes with Strombolian eruption.Their early-stage eruptions produced pyroclasts which formed scoria cone,tephra fall-out sheet and small-scale pyroclastic flow,while the late stage eruptions effused a great amount of lava.They have large cones with the elevation above 200～300 meters,and the cones are made up of cinder cone and spatter cone.Tephra fall-out sheet is around the cones.The effused lava flow from the two volcanoes underwent the lava type transition from pahoeoe lava to aa lava.According to the characteristics of volcanic products,the eruption style is presented as follows:explosive eruption with a sustained eruption column,Strombolian eruption,lava fountain eruption.The sustained eruption column characterizes the new style and makes it different from typical Strombolian eruption.The similar eruption as Yanshan and Gaoshan happened in Longgang Quaternary volcanic cluster and Holocene volcanic cluster in Jingbohu.It is a new eruption style in the continental volcanism in China.

Key words: Yanshan volcano, Gaoshan volcano, a new eruption style, Halaha River and Chaoer River volcanic cluster, Daxing’an Mountain Range

摘要： 在野外地质资料基础上,利用火山形态学方法,探讨了大兴安岭焰山、高山火山的喷发型式。结果表明,大兴安岭哈拉哈河-绰尔河火山群中的焰山和高山火山不同于斯通博利式喷发形成的火山,其早期爆破喷发的火山碎屑形成火山渣锥、空降火山碎屑席和小型火山碎屑流,晚期溢出大量熔岩。两火山具有较高大的锥体(标高200～300m以上),在结构上,松散火山砾、火山弹等构成下部的降落锥,熔结集块岩构成上部的溅落锥。由火山砾和火山灰组成的空降火山碎屑席分布在火山锥体周围。两火山溢出的熔岩经历了从结壳熔岩→翻花石→渣状熔岩的演变。根据喷发产物可推断焰山和高山火山具有以下喷发特征:爆破喷发形成持续的喷发柱→斯通博利式喷发→熔岩喷泉喷溢,其中以持续时间较长的喷发柱区别于典型的斯通博利式喷发。类似焰山、高山火山的喷发特征,在龙岗第四纪火山群、镜泊湖全新世火山群中也都有个例,这是中国大陆火山作用中一种新的喷发型式。

关键词: 焰山火山, 高山火山, 新的火山喷发型式, 哈拉哈河-绰尔河火山群, 大兴安岭