Large Macaronichnus in modern shoreface sediments : identification of the producer, the mode of formation, and paleoenvironmental implications
Large Macaronichnus in modern shoreface sediments : identification of the producer, the mode of formation, and paleoenvironmental implications
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现代岸面沉积物中的大型 Macaronichnus ：生产者的识别、形成模式和古环境影响
DOI：
10.1016/j.palaeo.2011.08.023
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Seike;K.;Yanagishima;S.;Nara M.;Sasaki;T.
痕迹化石Macaronichnus segregatis是一个层内足迹出现在浅海沉积。先前的研究表明，这种遗迹化石可以作为古海平面、海岸线方向、海滩形态动力学和古海洋学条件的有力指示物。在这里，我们描述了另一种类型的Macaronichnus，一种早期的大型Macaronichnus isp.，其直径为5- 12 mm，来自日本西部现代桑迪海滩的上滨面沉积物。洞穴是由选择性的沙粮喂养的opheliid多毛类Travisia japonica，虽然详细的机制仍不清楚。根据T. japonica和Travisia等种，大Macaronichnus isp.似乎更广泛地分布在潮滩、上下滨面、大陆架，甚至可能分布在深海海底。大潜穴的分布与标准潜穴有很大不同。分离因此，有必要区分洞穴的大小，以使用的遗迹属Macaronichnus作为古环境指标。
The trace fossil Macaronichnus segregatis is an intrastratal trail occurring in shallow marine deposits. Previous studies have shown that this trace fossil can be used as a powerful indicator of ancient sea level, shoreline orientation, beach morphodynamics, and paleoceanographic conditions. Here we describe another type of Macaronichnus, an incipient large Macaronichnus isp., which is 5–12mm in diameter, from upper shoreface deposits of a modern sandy beach in western Japan. The burrow is produced by selective sand-grain feeding of the opheliid polychaete Travisia japonica, although the detailed mechanism remains unclear. Based on the distribution of T. japonica and other Travisia species, large Macaronichnus isp. seems to be more widely distributed across tidal flats, the upper–lower shoreface, the continental shelf, and possibly even the deep-sea floor. The distribution of the large burrow is quite different to that of the standard M. segregatis. It is therefore necessary to distinguish between the sizes of the burrows in order to use the ichnogenus Macaronichnus as a paleoenvironmental indicator.