Geotechnical properties at DSDP Leg 66 Holes

Delineating the interrelationships between tectonics, sedimentation, and geotechnical properties is particularly important for areas subjected to the dynamic affects of convergence. DSDP Leg 66 drilling within the Middle America Trench complex provided a unique opportunity to investigate these interrelationships along a transect of eight drill sites beginning on the trench outer slope and traversing the trench, trench inner slope, and upper continental slope. Investigations of other convergent margins suggest that deformation occurs most rapidly along the lower trench inner slope and is reflected by the geotechnical properties (Carson, 1977; Seely, 1977; and von Huene, 1979). This study focuses on the geotechnical properties of Middle America Trench sediments and the possible affects of convergence on these properties.厘清构造作用、沉积作用与岩土特性之间的相互关联，对于受板块汇聚作用动态影响的区域而言尤为关键。深海钻探计划（Deep Sea Drilling Project，DSDP）第66航次在中美洲海沟复合体内部开展的钻探工作，为沿一条横跨8个钻探站位的剖面研究上述相互关联提供了独特契机——该剖面始于海沟外坡，依次穿过海沟、海沟内坡与大陆架上斜坡。针对其他汇聚型大陆边缘的研究表明，变形作用在海沟内坡下段发生最为迅速，且该特征可通过岩土特性得以体现（Carson，1977；Seely，1977；von Huene，1979）。本研究聚焦中美洲海沟沉积物的岩土特性，以及板块汇聚作用对这些特性可能产生的影响。