A Multi-Disciplinary Amazon Shelf Sediment Study (AmasSeds)

这个项目是早先一个项目的延续，该项目调查了亚马逊河河口附近大陆架上细颗粒沉积物的积累情况。最早的研究证明沉积物是主动堆积的，后来的研究发现了控制堆积的沉积过程。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。这项新的研究将作为AMasSeds(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，该研究是美国和巴西科学家的合作项目。该项目涉及物理、化学、生物和地质科学的合作。该项目将研究一系列时间和垂直尺度上全新世地层的形成机制。时间尺度将使用几种放射化学技术(Th-234、铅-210、Cs-137、C-14)进行评估，长度尺度将使用一系列取心(箱形岩心、卡斯滕岩心、活塞岩心、钻孔)和高分辨率地震技术(3.5千赫系统、低频系统)进行检查。与AMASSEDS其他小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，由此产生的地层学将以一系列观测技术(扫描电子显微镜、光学显微镜、X射线照相术、地震地层学)为特征。这项研究的重要性来自于它对一个主要的水下三角洲的评估，该三角洲是世界上最大的河流沉积物分散系统的典型代表。这些大系统对现代海洋产生了深远的影响，并有很好的潜力达到地质记录。研究区域是亚马逊河河口附近的大陆架，在那里，与这笔赠款相关的先前研究允许建立和测试关于地层形成的高级假设。

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.