Stratigraphic Evidence for Late Quaternary Temporal Clustering of Large Earthquakes on the Puente Hills Segment of the Elysian Park Thrust, Eastern Los Angeles.....

小威尔斯9416321 位于洛杉矶盆地东部的普恩特山是圣莫尼卡山脉-伊利森公园复背斜的地表表现，该复背斜对盲冲断斜坡上的运动做出响应。 这项研究将解决整个断层同时破裂的可能性，在一个非常大的地震事件，或在几个较小的北岭型事件，或在许多小事件的惠蒂尔狭窄类型。 通过分析穿越该结构的三条蜿蜒河流中的第四纪沉积物，以及含有交替的粗砂和富含有机物的河床，可以确定和比较Puente Hills逆冲斜坡上过去变形事件的时间。 这项研究将涉及在两个不同的尺度上使用石油和水井记录以及河流和海洋阶地沉积物进行分析，并对专门为此项目挖掘的钻孔进行高精度放射性碳测年和记录。 结果将提供与圣莫尼卡山脉-伊利森公园复背斜有关的过去地震的时间和震级的限制。

9416321 Wells The Puente Hills, in the eastern Los Angeles Basin, are the surface expression of the Santa Monica Mountains - Elysian Park anticlinorium which is forming the response to movement on blind thrust ramps. This study will address the likelihood of the entire fault rupturing simultaneously, in one very large earthquake event, or in several smaller events of Northridge- type, or in numerous small events of Whittier-Narrows-type. By analysis of Quaternary sediments in three meandering rivers that cross the structure and that contain alternating coarse sand and organic-rich beds, it will be possible to determine and compare the timing of past deformation events on the Puente Hills thrust ramp. The research will involve analyses at two distinct scales using oil and water well logs and fluvial and marine terrace deposits, and high- precision radiocarbon dating and logging of boreholes excavated specifically for this project. The results will provide constraints on the timing and magnitude of past earthquakes connected with the Santa Monica Mountains - Elysian Park anticlinorium.