Styles and productivity of mud diapirism along the Middle American Margin, Part I: Margin evolution, segmentation, dewatering and mud diapirism
Styles and productivity of mud diapirism along the Middle American Margin, Part I: Margin evolution, segmentation, dewatering and mud diapirism
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中美洲边缘泥底辟作用的类型和生产力，第一部分：边缘演化、分割、脱水和泥底辟作用
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
E. Suess
中科院分区：
文献类型：
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作者：
T. Moerz;A. Kopf;W. Brueckmann;H. Sahling;N. Fekete;V. Huehnerbach;D. Masson;D. Hepp;E. Suess
泥底辟作用是增生收敛边缘的常见现象，但在侵蚀边缘不常见。与泥底辟作用相关的流体喷发对于弧前的脱水以及由此导致的整个俯冲带的脱挥发具有重要意义。今天，哥斯达黎加近海的边缘被解释为侵蚀性的，并根据下行板块的粗糙度被细分为两个主要的结构域：北部是一个平滑的区域，那里起源于东太平洋隆起的正常海洋地壳，而南部是一个粗糙的区域，在那里边缘被科科斯山脊和众多邻近的火山海山碰撞而隆起和断裂。这些构造差异反映在火山弧产出、脱水机制以及弧前泥丘的丰度和几何形状的差异上。光滑域的底辟泥丘产状在中上坡最为丰富，与进入层序的最大压实水释放量明显无关。我们援引沉积速率的快速变化和由于楔的伸展断裂而增加的可容纳空间来解释观测到的土丘分布。
Mud diapirism is a common phenomenon of accretionary convergent margins but less common in erosive margins. Fluid venting associated with mud diapirism is of importance for the dewatering of the forearc and the resulting devolatilisation of the entire subduction zone. The margin offshore Costa Rica is today interpreted as erosive and subdivided into two major structural domains on grounds of the roughness of the downgoing plate: a smooth domain in the north where normal oceanic crust originating at the East Pacific Rise, and a rough southern domain where the margin is uplifted and fractured by the collision of the Cocos Ridge and numerous adjacent volcanic seamounts. These structural differences are reflected in differences in the output at the volcanic arc, dewatering mechanisms, and the abundance and geometry of mud mounds in the forearc. Diapiric mud mound occurrences in the smooth domain are most abundant in the middle and upper slope and apparently do not correlate with the maximum of compactional water release of the incoming sedimentary sequence. We invoke rapid changes in sedimentation rate and addition of accommodation space due to extensional faulting of the wedge to explain the observed mound distribution.