摘要
台湾浅滩陆坡具有活跃的重力流机制,发育了壮观的重力流沉积体系,是研究重力流动力学作用过程的理想场所。自陆架前缘直至深海的马尼拉海沟,发育了3个地貌坡折(包括一个陆架坡折和两个陆坡坡折)。这些地貌坡折控制了重力(流)的启动和整个演化过程,控制了各种重力流沉积体系的空间分布格局。其中陆架坡折控制了重力滑塌的产生,第一和第二陆坡坡折则分别控制了重力滑塌体、碎屑流、浊流的转换。本文利用重力流沉积物波的波形参数恢复了重力流流体有关参数,实证了研究区的确存在有非常活跃的重力流机制。而多级地貌坡折代表着陆坡地貌的不均衡和向均衡的演化,重力流的侵蚀-沉积效应只是陆坡体系调整过程的表现。
Gravity flow is active at shoal slope in Taiwan and this resulted in deposition of spectacular sedimentary system. It becomes an ideal area for studying gravity flow processing. At least three geomorphologic breaks including one shelf break and two slope breaks exist from shelf front to abyssal Manila Trench. These breaks control the initiation and entire evolution of the gravity flow and affect the distributing framework of gravity-flow-deposited system. Among them the shelf break controls the initiation of the mass waste, and the first and second slope break control transformation between slump, debris flow and turbidity flow, respectively. After utilizing the parameters of waveform of sediment wave, the corresponding rheology of gravity flow was reconstructed, demonstrating the existence of the active gravity flow. The multiple breaks mark the evolution of slope system from disequilibrium to equilibrium, while effect of erosion-deposition of gravity flow manifests the adjustment of the slope system.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2009年第6期812-819,共8页
Acta Geologica Sinica
基金
国家重点基础研究发展计划(编号2009CB219407)
国家自然科学基金项目(编号40572067)
中国地质大学(北京)海相储层演化与油气富集机理教育部重点实验室开放基金项目资助成果
