Chemical and mineral compositions of recent and ancient sediments and sedimentary rocks from the Mariana Trench@en

On the bed and on the ocean slope of the southern latitudinal part of the Mariana Trench ancient sediments, as well as sedimentary and igneous rocks are exposed. In the lower part of the sampled part of the studied section Late Oligocene to Early Miocene chalk-like limestones and marls occur. Upward marly tuffites and tuffs (apparently alternating with carbonate rocks) occur. These rocks are overlain by Early Miocene tuffaceous clays and siliceous-clayey muds. In the upper part of the section there are Pleistocene pelagic clays and ethmodiscus oozes.在马里亚纳海沟（Mariana Trench）南部纬度带的海床及洋坡上，裸露分布着古沉积物、沉积岩与火成岩。在所研究剖面的采样段下部，发育有渐新世晚期至中新世早期的白垩状灰岩与泥灰岩；向上依次出现凝灰质泥灰岩与凝灰岩（二者显然与碳酸盐岩互层产出）。上述岩石之上覆有中新世早期的凝灰质黏土与硅质黏土质泥；剖面的上部则发育有更新世远洋黏土及大洋藻（Ethmodiscus）软泥。