Petrology at DSDP Leg 66 Holes@en

The sandstone petrology of Leg 66 samples provides insights into changes through time in the geology of the source regions along the Guerrero portion of the Middle America continental margin. This in turn constrains possible models of the evolution of the Middle America Trench (e.g., de Czerna, 1971; Malfait and Dinkleman, 1972; Karig, 1974). Primarily medium-grained sands and sandstones, representing the widest variety available of trench/trench slope settings and ages, were analyzed in both light and heavy mineral studies. Standard techniques were used as much as possible in order to compare results from other margins and from ancient rocks.第66航次（Leg 66）样品的砂岩岩石学研究，为解析中美洲大陆边缘格雷罗段物源区的地质特征随时间的演化变化提供了关键视角。该研究结果进而为中美洲海沟（Middle America Trench）演化的多种可行模型提供了约束依据（例如de Czerna, 1971; Malfait and Dinkleman, 1972; Karig, 1974）。本次研究选取以中粒砂及砂岩为主的样品，这些样品涵盖了海沟/海沟斜坡最广泛的沉积环境与时代分布范围，并对其开展了轻矿物与重矿物分析。为便于与其他大陆边缘及古代岩石的相关研究结果进行对比，研究过程中尽可能采用了标准分析技术。