A Multi-Disciplinary Amazon Shelf Sediment Study (AmasSeds)

该项目是早期项目的延续，该项目调查了亚马逊河口附近大陆架上细颗粒沉积物的积累。最早的研究证实了沉积是主动成藏的，后来的研究确定了控制成藏的沉积过程。该项目将详细研究这些过程的运作以及它们如何影响沉积地层的形成。这项新研究将作为AmasSeds（一项多学科亚马逊陆架沉积物研究）的沉积学和地层学部分进行，这是美国和巴西科学家之间的合作项目。该项目涉及物理、化学、生物和地质科学的合作。该项目将在一定的时间和垂直长度范围内研究全新世地层形成的机制。时间尺度将使用几种放射化学技术（Th-234、Pb-210、Cs-137、C-14）进行评估，长度尺度将使用一系列取心技术（箱形取心、卡斯丁取心、活塞取心、钻孔取心）和高分辨率地震技术（3.5 khz系统、低频系统）进行检查。与其他AmasSeds组的合作将提供有关控制地层形成的沉积过程的大量信息，并将通过一系列观测技术（扫描电镜、光学显微镜、x射线照相、地震地层学）来表征所得到的地层学。这项研究的重要性在于它对一个主要的水下三角洲的评价，该三角洲是世界上最大的河流沉积物扩散系统的典型。这些大型系统对现代海洋有着深远的影响，并且很有可能达到地质记录。研究区域是亚马逊河口附近的大陆架，在那里，与这笔拨款相关的先前研究允许建立和测试有关地层形成的先进假设。

This project is a continuation of an earlier project that investigated the accumulation of fine-grained sediment on the continental shelf near the mouth of the Amazon River. The earliest research proved that sediment was actively accumulating, and later research identified the sedimentary processes controlling accumulation. This project will examine in detail the operation of the processes and how they affect the formation of sedimentary strata. This new research will be done as the Sedimentology and Stratigraphy portion of AmasSeds (A Multi-disciplinary Amazon Shelf SEDiment Study), which is a cooperative project between US and Brazilian scientists. The project involves collaboration of Physical, Chemical, Biological, and Geological Sciences. %%% The project will examine mechanisms of Holocene strata formation over a range of time and vertical-length scales. Time scales will be evaluated using several radiochemical techniques (Th-234,Pb-210, Cs-137, C-14) and length scales will be examined using a range of coring (box cores, kasten cores, piston cores, borings) and high-resolution seismic techniques (3.5-kHz system, lower-frequency system). Cooperation with the other groups of AmasSeds will provide much information about the sedimentary processes controlling strata formation, and the resulting stratigraphy will be characterized by a range of observational techniques (SEM, optical microscopy, x- radiography, seismic stratigraphy). The research derives importance from its evaluation of a major subaqueous delta, which is typical of the largest dispersal systems for fluvial sediment in the world. These large systems have a profound influence on modern oceans, and have a good potential for reaching the geological record. The study area is the continental shelf near the mouth of the Amazon River, where the previous research associated with this grant allows establishment and testing of advanced hypotheses regarding strata formation.