Deposits, petrology and mechanism of the 2010–2013 eruption of Kizimen volcano in Kamchatka, Russia
Deposits, petrology and mechanism of the 2010–2013 eruption of Kizimen volcano in Kamchatka, Russia
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俄罗斯堪察加半岛克济门火山2010-2013年喷发的沉积物、岩石学和机制
DOI：
10.1007/s00445-018-1199-z
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发表时间：
2018
影响因子：
3.5
通讯作者：
M. Belousova
中科院分区：
文献类型：
--
作者：
A. Auer;A. Belousov;M. Belousova
堪察加半岛的克济门火山以富含从英安岩到玄武质安山岩等高度非均质、低混合岩浆的来源而闻名。 2010 年至 2013 年，该火山发生了历史上第一次岩浆喷发，沉积了 0.27 平方公里的块状和火山灰火山碎屑流，同时缓慢挤出了 200 米厚、高粘性（1010–1011 Pa s）块状熔岩流，体积为 0.3 平方公里。喷发岩浆的总体积约为 0.4 km3 DRE。我们提供喷发年代学以及喷发产物的岩性和岩石学的描述。喷发物质以带状英安岩和高硅安山岩为代表。英安质岩浆是在数百年前的上一次岩浆喷发后的长期休眠过程中形成的，其矿物成分表明平均喷发前温度约为 810 °C，fO2 高于镍镍氧化物 (NNO) 缓冲层 0.9–1.6 个对数单位，浅层地壳储存条件约为 123 MPa。富含二氧化硅的安山岩代表了一种混合岩浆，显示出近期热和成分不平衡的迹象。我们认为混合岩浆开始形成于1963年，当时一系列深部地震表明镁铁质岩浆从深处输入到6-11公里深的硅质岩浆房中。接下来的 46 年里，充满房间的岩浆才达到可喷发的状态。两种熔体混合不良的原因是其异常高的粘度，这可能与喷发前挥发物通过区域构造断层从熔室中长期泄漏有关。我们的研究表明，表现出强烈持续的喷气孔活动的休眠火山的浅层岩浆室可能含有高度粘稠的、演化成分的脱气岩浆。通过注入碱性岩浆来重新激活此类岩浆室需要很长时间（几十年）。因此，此类火山的喷发预测应包括一系列深层地震（表明基性岩浆从深处的补给）与随后的一系列浅层地震（表明混合岩浆最终上升到地表）之间存在长时间滞后的可能性。由于岩浆粘度较高，浅层群可以持续一年以上。即将到来的喷发可能具有中度至低度的爆炸性，包括粘性熔岩流和由对比成分混合不良的岩浆组成的圆顶的挤出。
Kizimen volcano in Kamchatka is well known as a source of highly heterogeneous poorly mingled magmas ranging from dacites to basaltic andesites. In 2010–2013, the volcano produced its first historical magmatic eruption with the deposition of 0.27 km3 of block and ash pyroclastic flows accompanied by slow extrusion of a 200-m-thick, highly viscous (1010–1011 Pa s) block lava flow with a volume of 0.3 km3. The total volume of erupted magma comprised approximately 0.4 km3 DRE. We provide description of the eruption chronology, as well as the lithology and petrology of eruptive products. The erupted material is represented by banded dacite and high-silica andesite. The dacitic magma was formed during a long dormancy after the previous magmatic eruption several hundred years ago with mineral compositions indicating average pre-eruptive temperatures of ~ 810 °C, fO2 of 0.9–1.6 log units above the nickel–nickel oxide (NNO) buffer and shallow crustal storage conditions at ~ 123 MPa. The silica-rich andesite represents a hybrid magma, which shows signs of recent thermal and compositional disequilibrium. We suggest that the hybrid magma started to form in 1963 when a swarm of deep earthquakes indicated an input of mafic magma from depth into the 6–11-km-deep silicic magma chamber. It took the following 46 years until the magma filling the chamber reached an eruptible state. Poor mingling of the two melts is attributed to its unusually high viscosity that could be associated with the pre-eruptive long-term leakage of volatiles from the chamber through a regional tectonic fault. Our investigations have shown that shallow magma chambers of dormant volcanoes demonstrating strong persistent fumarolic activity can contain highly viscous, degassed magma of evolved composition. Reactivation of such magma chambers by injection of basic magma takes a long time (several decades). Thus, eruption forecasts at such volcanoes should include a possibility of long time lag between a swarm of deep earthquakes (indicating the recharge of basic magma from depth) and the following swarm of shallow earthquakes (indicating final ascent of the hybrid magma towards the surface). Due to the high viscosity of the magma, the shallow swarm can last for more than a year. The forthcoming eruption can be of moderate to low explosivity and include extrusion of viscous lava flows and domes composed of poorly mingled magmas of contrasting compositions.
鲁阿佩胡火山岩浆过程的扩散计时及其与监测数据的比较
影响因子：
2.9
作者：
Kilgour G
通讯作者：
Kilgour G