...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>GSA Bulletin >Structural and petrologic evolution of the Lihue basin and eastern Kauai, Hawaii
【24h】

Structural and petrologic evolution of the Lihue basin and eastern Kauai, Hawaii

机译：夏威夷利胡埃盆地和东部考艾岛的结构和岩石学演化

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

The topography of the eastern part of the Hawaiian island of Kauai is dominated by the Lihue basin, a large (110 km2) semicircular depression bounded by steep cliffs and partly filled by late rejuvenated-stage (or posterosional stage) volcanic material. As with other large, semicircular basins on ocean-island volcanoes, the subsurface geology and origin (e.g., structural collapse vs. fluvial erosion) of the Lihue basin are poorly understood. New analyses of samples collected from eastern Kauai and drill holes within the basin document several important features of the late-stage geologic evolution of Kauai. First, thick (>300 m) sequences of rejuvenated-stage Koloa Volcanics in the Lihue basin show systematic, basin-wide geochemical trends of increasingly incompatible elements with time, indicating a gradual decrease in the extent of partial melting of mantle sources with time. Second, beneath the rejuvenated-stage volcanics in the basin, a thin layer of postshield alkalic stage lavas (e.g., hawaiites and mugearites) overlies older shield-stage tholeiitic lavas of the Napali Member, indicating that the Lihue basin formed by structural collapse, not fluvial erosion. Third, a large (2–5 km3) matrix-supported breccia, interpreted as deposits of one or more debris flows, is within the rejuvenated-stage volcanics throughout the basin, and correlates with surficial exposures of the Palikea Breccia west of the basin. Isotopic compositions of the bulk breccia are similar to those of tholeiites from the east side of Kauai, and distinct from those of west Kauai tholeiites. Clasts within the breccia are dominantly hawaiite and alkali gabbro. The source region of the breccia in the steep cliffs and highlands of the central massif to the west of the basin must contain magmatic products of an extensive postshield alkalic stage, including hawaiite flows and one or more large intrusive bodies or ponded sequences of alkali gabbro.
机译：夏威夷岛 Kauai东部的地形主要由Lihue盆地控制，该盆地是一个大型（110 km 2 ）半圆形 凹陷凹陷被陡峭的悬崖所覆盖，并由回春阶段（或后生阶段）的火山物质部分填充。 与大岛火山上的其他大型半圆形盆地一样， < / sup>对Lihue盆地的地下地质和成因（例如，构造塌陷 vs。河流侵蚀）了解甚少。 从考艾岛东部和钻探收集的样品的新分析盆地内的 孔记录了考艾岛后期地质演化的几个重要特征。首先，盆地里胡（Lihue ）的新生阶段科洛亚火山的厚层（> 300 m）序列显示了越来越大的 的系统性，全盆地范围的地球化学趋势。与时间不兼容的元素，表明地幔源部分融化的程度随时间逐渐降低。 第二，盆地中回生阶段的火山下面， 后盾碱性阶段熔岩的薄层（例如，夏威夷岩和硅藻土）覆盖在纳帕里成员的较老的盾构阶段熔岩 上，这表明利胡埃盆地是由结构坍塌而不是河流侵蚀形成的。第三，大 （2–5 km 3 ）矩阵支撑的角砾岩被解释为位于一个或多个泥石流中的沉积物 。整个盆地都恢复了生长期的 火山作用，并且与盆地西面的Palikea Breccia的表面 暴露有关。大块角砾岩的同位素 组成与考艾岛东部的异黄岩 相似，与西 考艾氏异形岩不同。角砾岩中的碎屑主要是夏威夷岩 和碱辉石。盆地中西部陡峭的 悬崖和高地中角砾岩的源区必须包含广泛的后盾 碱性阶段，包括夏威夷岩流和一个或多个较大的 侵入体或碱性辉长岩的沉陷序列。

著录项

  • 来源
    《GSA Bulletin》 |1999年第5期|674-685|共12页
  • 作者

    Peter W. Reiners; Bruce K. Nelson; Scot K. Izuka;

  • 作者单位

    Department of Geological Sciences, Box 351310, University of Washington, Seattle, Washington 98195;

    Department of Geological Sciences, Box 351310, University of Washington, Seattle, Washington 98195;

    U.S. Geological Survey, Water Resources Division, 677 Ala Moana Boulevard, Suite 415, Honolulu, Hawaii 96813;

  • 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
  • 专利
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