• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Late Pleistocene to Holocene geomorphic and structural evolution of the Camarillo Fold Belt, California.
【24h】

Late Pleistocene to Holocene geomorphic and structural evolution of the Camarillo Fold Belt, California.

机译：加利福尼亚Camarillo褶皱带的晚更新世至全新世地貌和结构演化。

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 Camarillo Fold Belt (CFB) is composed of several south-verging anticlines, which comprise the western extent of the west-trending highly segmented Simi fault zone that extends from the northern Simi Valley to the city of Camarillo. Geologic mapping, GIS-based topographic analyses, optically stimulated luminescence (OSL) and radiocarbon dating, and subsurface well logs are integrated to bracket the relative timing of deformation on active faults, to develop a chronology of deformed surfaces, and to better constrain the age of the Saugus Formation in this part of the Western Transverse Ranges. New geochronology of the Saugus Formation exposed in the study area indicates that the strata are an order of magnitude younger than previously thought (∼20ka vs. 200ka). This chronologic revision has significant implications for the timing and rates of deformation, as well as for the seismic hazard in the study area.;Many of the Quaternary transpressional faults are reactivated Miocene high-angle (70-80°) transrotational faults. Where the age of deformed sediments is well-known, minimum vertical uplift rates on several of the active faults are ∼1.5 mm/yr, which is 3-times greater than most previous estimates based on paleoseismic investigations. Discrete structural domains are characterized by west-plunging anticlines, changes in the orientation and loci of active structures, and they are bound by fault segment boundaries that are often characterized by orthogonal north-striking faults. Structural relief and the age of deformation decrease from east to west across each successive north-striking fault. We interpret these relations to suggest that westward propagation of the fold belt occurred by punctuated lateral growth of the Simi fault due to the presence of north-trending faults. This style of deformation may be common in the Western Transverse Ranges and has important implications for seismic hazard assessment.;Geochronology of geomorphic surfaces indicates that the landscape evolution in the CFB was modulated by global climate change. A regionally extensive erosion surface in the study (45 km2) in the study area was cut during Marine Isotope Stage 2 (MIS2; 19-24 ka). Incision from 19-12 ka resulted in deep canyons cut throughout the study area, which were back-tilled following the Pleistocene Holocene transition (12-4 ka).
机译：Camarillo褶皱带（CFB）由多条向南的背斜线组成，包括从西斯谷北部延伸至Camarillo市的西向高度分割的Simi断层带的西部范围。整合了地质制图，基于GIS的地形分析，光学激发发光（OSL）和放射性碳测年以及地下测井记录，以记录活动断层变形的相对时间，以形成变形表面的时间顺序，并更好地限制年龄西部横向山脉这一部分的Saugus地层。研究区暴露的索格斯组新的年代学表明，该地层比以前认为的要年轻一个数量级（约20ka对200ka）。该年代学修订对研究的时机和变形速率以及研究区域的地震危险具有重要意义。许多第四纪压断层是中新世中转高角度（70-80°）变旋断层。在众所周知的变形沉积物年龄的情况下，几个活动断层的最小垂直抬升速率约为每年1.5毫米，这比以前根据古地震调查得出的估计值高出三倍。离散的结构域的特征是向西俯冲的背斜，活动结构的方位和轨迹的变化，并且它们受到通常以正交北向断裂为特征的断层段边界的束缚。在每个连续的北向断裂中，构造起伏和变形年龄从东向西减小。我们解释这些关系以表明褶皱带的向西传播是由于北向断裂的存在而导致的西米断裂的点状横向生长所引起的。这种变形形式可能在西部横向山脉很普遍，并且对地震危险性评估具有重要意义。地貌表面的年代学表明，CFB中的景观演化受全球气候变化的调节。在海洋同位素第二阶段（MIS2； 19-24 ka）期间，研究区域的研究区域（45 km2）被广泛侵蚀。从19-12 ka切开导致在整个研究区域切开深峡谷，这些峡谷在更新世全新世过渡（12-4 ka）之后向后倾斜。

著录项

  • 作者

    DeVecchio, Duane Edward.;

  • 作者单位

    University of California, Santa Barbara.;

  • 授予单位 University of California, Santa Barbara.;
  • 学科 Geology.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 121 p.
  • 总页数 121
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 地质学;
  • 关键词

  • 入库时间 2022-08-17 11:38:25

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