Interaction Between Plate Convergence and Fan Sedimentation:GLORIA Side-Scan Sonar and Seismic Data from the Northern Colombian Convergent Margin

首席调查员将利用1989年夏季在RRS查尔斯·达尔文号上收集的Gloria图像和单通道地震数据，调查位于哥伦比亚北部会聚边缘的Magdelena扇上没有变形的情况。已经提出了两个相互竞争的型号来解释风扇上没有缩短的原因。一种认为，扇的低地表坡度抑制了变形，因此沉积速率会改变挤压变形的几何形状。在另一种模式中，南美洲北部的地块构造沿着不同的地块创造了不同程度的汇聚。如果块体边界断层继续沿着活动的吸积楔向近海延伸，那么跨块体边界的汇聚量应该会发生变化。这些模型将通过确定风扇边缘附近的几何形状、变形速率和时间进行测试。

The Principal Investigator will investigate the absence of deformation on the Magdelena fan, located on the northern Colombian convergent margin, using GLORIA images and single-channel seismic data collected in the summer of 1989 on the RRS Charles Darwin. Two competing models have been proposed to explain the lack of shortening on the fan. One proposes that the low surface slope of the fan suppresses deformation; thus sedimentation rates would alter the geometry of compressional deformation. In the other model, block tectonics in northern South America creates different amounts of convergence along the various blocks. If the block-boundary faults continue offshore across the active accretinary wedge then the amount of convergence should change across block boundaries. These models will be tested by determining the geometry, and rates and timing of the deformation near the edges of the fan.