...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Geosphere >A 250 k.y. record of Cascade arc pyroclastic volcanism from late Pleistocene lacustrine sediments near Summer Lake, Oregon, USA
【24h】

A 250 k.y. record of Cascade arc pyroclastic volcanism from late Pleistocene lacustrine sediments near Summer Lake, Oregon, USA

机译：250千米美国俄勒冈州萨默湖附近晚更新世湖相沉积物的级联弧热碎屑火山作用的记录

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

Distal tephra beds provide important records of pyroclastic volcanism that enhance our overall understanding of eruptive frequencies, magnitudes, compositions, and hazards. Some beds also serve as widespread chronostratigraphic markers. Lacustrine sediments near Summer Lake, Oregon (United States), record numerous eruptions of Cascade arc sources over a period exceeding 2.5 m.y. Late Pleistocene sediments exposed in outcrop have yielded 88 visible tephra beds, including many beds not previously documented. Of these beds, 44 are characterized by rhyolitic glass, 40 contain predominantly basaltic or intermediate glass, and 4 are strongly heterogeneous in composition. Only 23 have been correlated to deposits outside of the Summer Lake basin. The remaining 65 beds provide a record of Cascade arc volcanism that is as yet unique to Summer Lake. Age-depth relations are well constrained for the upper 6 m of section, but are less certain in the lower 12.4 m. Tephra correlations and an overall age model suggest the following: bed B1 originates from an eruption of Mount Mazama (Crater Lake) ca. 20 ka. Beds I and W likely originate from eruptions of Mount St. Helens ca. 80 and 190 ka. A 7-cm-thick tephra bed correlated to Shevlin Park Tuff probably dates to ca. 198 ka. Tephra correlated to the Antelope Well tuff from Medicine Lake volcano dates to ca. 215 ka. Bed NN, at the base of the section, has an estimated age of at least 240–250 ka and probably originated from Newberry Volcano. Overall, this record significantly refines the Pleistocene tephrostratigraphic framework for western North America.
机译：远端的特弗拉层提供了火山碎屑火山作用的重要记录，这些记录增强了我们对火山爆发频率，幅度，组成和危害的总体了解。一些床 也可以用作广泛的年代地层标记。美国俄勒冈州萨默湖附近的Lacustrine 沉积物在超过2.5 m.y的时间段内记录了许多级联弧源的 爆发。在露头露露的晚更新世沉积物产生了 88个可见的特非拉床，包括许多以前没有记载的床。 这些床中有44个以流纹玻璃为特征，其中40个包含 主要是玄武岩或中级玻璃，其中4种在组成上具有很强的 异质性。只有23个与夏季湖盆地外的 沉积物相关。剩余的65张 床提供了Cascade弧形火山记录，该记录到目前为止对Summer Lake还是 唯一的。深度-深度关系对于断面的上部6 m很好地受约束，但在下部 12.4 m处不确定。 Tephra相关性和总体年龄模型表明， 如下：床B1起源于ca Mazama （克拉特湖）的喷发。 20 ka。床I和W可能源自圣海伦斯山的 爆发。 80和190 ka。与Shevlin Park Tuff相关的7cm厚的 tephra床可能要追溯到 ca。 198卡。特非拉（Tephra）与 Medicine Lake volcano的羚羊井凝灰岩有关，可追溯到约公元前约2年。 215卡。位于该部分底部 的Bed NN的估计年龄至少为240–250 ka，可能起源于纽伯里火山。总体而言，此 记录显着完善了北美西部的更新世造斜古地理学 框架。

著录项

  • 来源
    《Geosphere》 |2010年第4期|397-429|共33页
  • 作者

    Stephen C. Kuehn; Robert M. Negrini;

  • 作者单位

    Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada;

    Department of Physics and Geology, California State University, Bakersfield, California 93311, USA;

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

相似文献

  • 外文文献
  • 中文文献
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