Fine-grained turbidites of the Amazon fan : Facies characterization and interpretation
Fine-grained turbidites of the Amazon fan : Facies characterization and interpretation
复制标题
DOI：
10.2973/odp.proc.sr.155.208.1997
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
D. Piper;M. Deptuck
中科院分区：
文献类型：
--
作者：
D. Piper;M. Deptuck
在亚马逊扇堤坝上发现的大部分沉积物厚度是由带有粉砂纹层的泥造成的。尖基递变层的分布和生物扰动作用、成岩前缘和超微化石的分布表明，许多层是快速和幕式沉积的。泥质总厚度在远离活动河道处急剧减小。这些观察结果表明，大多数堤坝是由细粒浊积岩建造的。通过岩心观察、X射线照相和粒度分析，识别出12种细粒浊积岩相。某些相似乎是特定扇背景的特征。泥质和粉砂薄层的模态粒度均随扇下方向减小。相分布与浊流沿河道系统向下流动时的渐进溢出相一致。
Much of the sediment thickness found on Amazon Fan levees is attributed to mud with silt laminae. The distribution of sharp-based graded beds and the distribution of bioturbation, diagenetic fronts, and nannofossils demonstrates that many of the beds were deposited rapidly and episodically. The total thickness of mud decreases sharply away from active channels. These observations suggest that most of the levees are built of fine-grained turbidites. Twelve facies of fine-grained turbidites are distinguished from visual core description, X-radiography, and grain-size analysis. Some facies appear diagnostic of particular fan settings. Modal grain size of both muds and thin silt laminae decreases downfan. Facies distribution is consistent with the progressive spillover of a turbidity current as it moves down the channel system.