THE STRATIGRAPHIC AND SEDIMENTOLOGIC FRAMEWORK OF FINE-SCALE FAUNAL REPLACEMENTS IN THE MIDDLE MIOCENE OF THE VIENNA BASIN (AUSTRIA)
THE STRATIGRAPHIC AND SEDIMENTOLOGIC FRAMEWORK OF FINE-SCALE FAUNAL REPLACEMENTS IN THE MIDDLE MIOCENE OF THE VIENNA BASIN (AUSTRIA)
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维也纳盆地中中新世小规模动物群更替的地层和沉积学框架（奥地利）
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
O. Mandic
中科院分区：
文献类型：
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作者：
M. Zuschin;M. Harzhauser;O. Mandic
研究了中新世中新世(巴登期)一小段(∼16m)的细尺度古群落动态，该剖面由硅质碎屑岩、泥质岩和砂质到重度浅水沉积组成。晚高水位体系域的两个基本的向上粗化和变浅的准层序被三级层序界面与剖面顶部的海侵体系域的加深向上的基底部分隔开。该序列中的底栖动物群主要是原生的、受风暴影响的平底组合，但在海侵体系域的底部附近出现了明显的牡蛎-Vermetid界岩。此外，还包括三个风暴壳层，它们在伴生的盆地环境中被发现是无序的；它们的动物群内容与海侵体系域最深的细粒部分密切相关。利用去趋势对应分析和相似性分析对物种和样本进行排序，表明可以区分两个基本的底栖生物组合。牡蛎-Vermetid界线与一套独特的环境条件有关，表明层序界面发生了重大的环境变化。边界岩中的动物群组合显示出向泥质(较深和平静的水)平-底组合的弱梯度，而泥质(较深和平静的水)平-底组合的特征是与砂质(较浅和较搅动的)生境的动物群强烈重叠。因此，研究剖面的底栖生物组合属于同一基本后生群落，不受层序界面和泛滥面上强烈的相变化的严重影响。此外，所研究的底栖生物组合中的物种通过栖息地跟踪对环境变化做出反应。
Abstract Fine-scale paleocommunity dynamics were studied in a short (∼16 m) section in the Middle Miocene (Badenian Stage) of the Central Paratethys, which consists of siliciclastic, pelitic, and sandy-to-gravely shallow-water deposits. Two basal, coarsening- and shallowing-upward parasequences of a late highstand systems tract are separated by a third-order sequence boundary from the deepening-upward basal part of a transgressive systems tract at the top of the section. Benthic faunas in this succession are primarily autochthonous and storm-influenced, level-bottom assemblages, but a distinct oyster-vermetid boundstone occurs near the base of the transgressive systems tract. Additionally, three tempestitic shell beds were included, which were found out of sequence in an associated basinal setting; their faunal content relates them closely to the fine-grained deepest parts of the transgressive systems tract. Ordination of species and samples using detrended correspondence analysis and analysis of similarity suggest that two basic benthic assemblages can be distinguished. The oyster-vermetid boundstone is tied to a unique set of environmental conditions and indicates a major environmental change at the sequence boundary. The faunal assemblage in the boundstone shows a weak gradient into the pelitic (deeper and quiet-water) level-bottom assemblage, which in turn is characterized by strong overlaps with the fauna of sandy (shallower and more agitated) habitats. Therefore it is concluded that the benthic assemblages in the studied section belong to the same basic metacommunity, which was not seriously affected by the strong facies changes at the sequence boundary and at the flooding surfaces. Moreover, the species in the studied benthic assemblages reacted to changes in the environment by habitat tracking.