...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Volcanology and Geothermal Research >Rates of water exsolution and magma ascent inferred from microstructures and chemical analyses of the Tokachi-Ishizawa obsidian lava, Shirataki, northern Hokkaido, Japan
【24h】

Rates of water exsolution and magma ascent inferred from microstructures and chemical analyses of the Tokachi-Ishizawa obsidian lava, Shirataki, northern Hokkaido, Japan

机译：从北海道北部白rat市的十胜-石泽黑曜石熔岩的微观结构和化学分析推断出的水浸出率和岩浆上升速率

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Very few quantitative textural data exist for viscous obsidian lava eruptions, and it is still unclear from the mechanical behavior of ascending magmas if outgassing is controlled dominantly by brittle or ductile deformatioa In order to obtain insights into how degassing and ascent proceed in such highly viscous magmas, we conducted textural and chemical analyses of the Tokachi-Ishizawa (TI) obsidian lava, in the Shirataki rhyolite volcanic area, northern Hokkaido, Japan, and estimated the water exsolution rate and ascent rate. The storage conditions of the TI lava are estimated from the Rhyolite-MELTS program as T = 840-860 ℃ and P = 50 MPa using the mineral assemblages and the chemical compositions of plagioclase phenocrysts and glass. To estimate the magma ascent rate, we measured the length, width, and number of oxide microlites using three-dimensional techniques. Textural analysis indicates that the microlite number densities (Nv [number/m~3]) of oxide microlites in TI lava samples are 2.1 × 10~(13) to 1.4 × 10~(14), which correspond to water exsolution rates of 3.5 × 10~(-9) to 1.7 × 10~(-8) wt.%/s and ascent rates of 1.7 × 10~(-6) to 1.1 × 10~(-5) m/s. Together with an estimate of viscosity, the inferred ascent velocities allow us to examine the mechanical behavior of the magma in the conduit We conclude that the development of permeability leading to outgassing is controlled by ductile deformation rather than brittle fracturing.
机译：粘性黑曜石熔岩喷发的定量定量结构数据很少，从上升的岩浆的力学行为尚不清楚，是否主要通过脆性或延性变形来控制脱气，以便深入了解在如此高粘度的岩浆中如何进行脱气和上升，我们对日本北海道北部白rat流纹岩火山区的十胜-石泽（TI）黑曜石熔岩进行了结构和化学分析，并估算了水的渗透率和上升率。 TI熔岩的储存条件是根据Rhyolite-MELTS程序估算的，其温度为T = 840-860℃，P = 50 MPa，使用矿物组合以及斜长石斑晶和玻璃的化学成分。为了估算岩浆上升速率，我们使用三维技术测量了氧化物微晶的长度，宽度和数量。结构分析表明，TI熔岩样品中氧化物微晶的微晶数密度（Nv [number / m〜3]）为2.1×10〜（13）至1.4×10〜（14），对应水浸出率为3.5 ×10〜（-9）至1.7×10〜（-8）wt。％/ s，上升速率为1.7×10〜（-6）至1.1×10〜（-5）m / s。连同粘度的估计值一起，推断的上升速度使我们能够检查管道中岩浆的机械行为。我们得出结论，导致渗气的渗透性的发展是由韧性变形而不是脆性破裂控制的。

著录项

  • 来源
  • 作者

    Kyohei Sano; Keiji Wada; Eiichi Sato;

  • 作者单位

    Earth Science Laboratory, Course of Subjects Education, Graduate School of Education, Hokkaido University of Education at Asahikawa, Hokumon 9, Asahikawa, Hokkaido 070-8621, Japan,Department of Earth and Planetary Sciences, Graduate School of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan;

    Earth Science Laboratory, Course of Subjects Education, Graduate School of Education, Hokkaido University of Education at Asahikawa, Hokumon 9, Asahikawa, Hokkaido 070-8621, Japan;

    Institute for Promotion of Higher Education, Kobe University, Tsurukabuto 1-2-1, Nada, Kobe 657-8501, Japan;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Textural analysis; Obsidian-rhyolite lava flow; Magma ascent rate; Outgassing mechanism;

    机译：纹理分析;黑曜石流纹岩熔岩流;岩浆上升率;除气机制;

相似文献

  • 外文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号