五大连池新期火山锥体结构及喷发过程

Cone Structure and Eruption Process of Modern Volcanoes in the Wudalianchi Area,Heilongjiang Province

五大连池新期火山(1719～1921年喷发)包括老黑山和火烧山两座火山。火山由富钾玄武质熔岩盾和锥体组成,造盾喷溢与造锥喷发交替进行。老黑山形成相对较早,喷发规模大,锥体结构复杂,为两期形成的复式套叠锥,晚期锥体中心为漏斗状火山口,火山喷发过程可分为5个阶段。火烧山为一单锥,锥体中心发育破火口,火山活动经历了3个阶段。

Modern volcanoes in the Wudalianchi area erupting during 1719～1721 ,i. e. the Laoheishan and Huoshaoshan volcanoes, consist of potassium-rich basaltic lava shields and pyroclastic cones. Shield-forming lava flows and cone-forming pyroclastic eruptions took place successively. The Laoheishan volcano emerged earlier, erupted in greater scale and produced more complicated cone structure than the Huoshaoshan. A funnel-shaped crater, in the center of Laoheishan two-episode overlap cone, formed in the later episode. Its eruption process may be divided into five stages. The Huoshaoshan volcano, a single-cone volcano with a central caldera, underwent three stages.