Delta Double-Stack: Juxtaposed Holocene and Pleistocene Sequences from the Bengal Basin, Bangladesh
Delta Double-Stack: Juxtaposed Holocene and Pleistocene Sequences from the Bengal Basin, Bangladesh
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三角洲双叠层：孟加拉国孟加拉盆地的并列全新世和更新世层序
DOI：
10.2110/sedred.2009.3.4
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发表时间：
2009
期刊：
影响因子：
9.2
通讯作者：
Sirajur R. Khan
中科院分区：
文献类型：
--
作者：
Russell D. Pate;S. Goodbred;Sirajur R. Khan
4 | 2009 年 9 月 摘要 类比——古代的和现代的——是我们理解和解释地层记录的关键，而地层记录往往不完整且很少公开。在这里，我们描述了一个向上粗化的全新世三角洲序列，它不整合地位于另一个非常相似的更新世三角洲序列上。考虑到过去 200 ka 期间海平面低位和河流切割的长期存在，这样一个完整且保存完好的更新世例子是罕见的。这些堆积的三角洲序列使我们能够考虑我们经过充分研究的全新世类似物是多么相似。比较揭示了几乎相同的相序列，仅在三角洲对海平面上升的响应的相对时间上存在微小差异。然而，一个关键的区别是更新世序列中的独特相，这表明喜马拉雅山的大洪水可能会在冰期-间冰期气候转变期间周期性地影响孟加拉边缘。
4 | September 2009 ABSTRACT Analogs – ancient and modern – are key to our understanding and interpretation of the stratigraphic record, which is too often incomplete and sparingly exposed. Here we describe an upwardcoarsening Holocene delta sequence that sits unconformably on another, remarkably comparable, delta sequence of Pleistocene age. Such a complete and well-preserved Pleistocene example is rare given extended periods of sea-level lowstand and fluvial incision during the past 200 ka.These stacked delta sequences allow us to consider how analogous our well-studied Holocene analogs are.The comparison reveals a nearly identical facies succession, with modest differences only in the relative timing of delta response to rising sea level. One key difference, though, is a unique facies in the Pleistocene sequence suggesting that major floods from the Himalayas impact the Bengal margin, perhaps periodically, during glacial-interglacial climate transitions.