...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Geochemistry, geophysics, geosystems >New geophysical constraints on a failed subduction initiation: The structure and potential evolution of the Gagua Ridge and Huatung Basin
【24h】

New geophysical constraints on a failed subduction initiation: The structure and potential evolution of the Gagua Ridge and Huatung Basin

机译：俯冲失败引发的新地球物理约束：加瓜岭和华东盆地的结构和潜在演化

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

We modeled the velocity structure of the Huatung Basin and Gagua Ridge using offshore wide-angle seismic data along four approximate to E-W transects. These transects are accompanied by several multichannel seismic reflection (MCS) profiles that highlight the shallow deformation in this area east of Taiwan. Although it is agreed that the Gagua Ridge was the product of a transient compressional episode in the past, relatively few data have been collected that reveal the deeper structure resulting from this enigmatic process. The velocity models show evidence for normal, to thin, oceanic crustal thicknesses in the Huatung Basin and West Philippine Basin. Moho reflections from the associated MCS profiles confirm the thickness observed in the velocity models. The velocity models indicate significant crustal thickening associated with the Gagua Ridge, to 12-18 km along its entire length. Most importantly, the two central velocity models also show a significant asymmetry in the crustal thickening, suggesting a westward underthrusting of >20 km of WPB oceanic crust beneath that of the Huatung Basin. This geometry is extremely unexpected given interpretations that indicate the Huatung Basin could be significantly older than the West Philippine Basin (Early Cretaceous versus Eocene). Our observations, along with recent geophysical data concerning the age of the Huatung Basin, indicate that the Gagua Ridge was the result of a failed subduction event during the Miocene that may have existed simultaneously and for a short time, competed with the Manila subduction zone to the west in accommodating convergence between the Eurasia and Philippine Sea plates. In this scenario, the present-day Gagua Ridge represents a snapshot of a failed subduction initiation preserved in the geologic record.
机译：我们利用沿四个近似E-W断面的近海广角地震数据对华东盆地和加瓜岭的速度结构进行了建模。这些样带伴有多个多通道地震反射（MCS）剖面，这些剖面突出了台湾东部该地区的浅层变形。尽管过去人们认为加瓜岭是短暂性压迫发作的产物，但收集到的数据很少，揭示了这种神秘过程产生的更深层结构。速度模型为华东盆地和西菲律宾盆地的正常，薄至海洋地壳厚度提供了证据。来自相关联的MCS轮廓的Moho反射确认了速度模型中观察到的厚度。速度模型表明，与加瓜岭相关的地壳明显增厚，沿其整个长度达到12-18公里。最重要的是，这两个中心速度模型也显示出地壳增厚的显着不对称性，这表明在华东盆地之下，WPB大洋地壳向西逆冲> 20 km。考虑到表明华东盆地可能比西菲律宾盆地（早白垩世与始新世）早得多的解释，这种几何形状是极其出乎意料的。我们的观察结果以及有关华东盆地年龄的最新地球物理数据表明，加瓜海岭是中新世一次俯冲失败事件的结果，该事件可能同时存在并存在很短时间，与马尼拉俯冲带竞争。西部以适应欧亚大陆与菲律宾海板块之间的交汇。在这种情况下，今天的加瓜岭代表了地质记录中保存的俯冲失败的快照。

著录项

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