Non-palimpsested crowded Skolithos ichnofabrics in a Carboniferous tidal rhythmite: Disentangling ecological signatures from the spatio-temporal bias of outcrop
Non-palimpsested crowded Skolithos ichnofabrics in a Carboniferous tidal rhythmite: Disentangling ecological signatures from the spatio-temporal bias of outcrop
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DOI：
10.1111/sed.12947
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发表时间：
2021-10-18
期刊：
影响因子：
3.5
通讯作者：
Herron, Sean T.
中科院分区：
文献类型：
--
作者：
Allport, Hamilton A.;Davies, Neil S.;Herron, Sean T.
在英国诺森伯兰郡中石炭世（Serpukhovian）阿尔斯顿组剖面中发现了一个产生小潮束的异石潮坪序列。韵律岩记录的沉积时间间隔至少可以确定为84个太阴日，并证明了密西西比晚期西北欧航道部分地区不可忽略的潮差。值得注意的是，在两个层面和垂直剖面上，潮积岩都存在一个引人注目的拥挤的Skolithos遗迹组构。层面表达的遗迹组构揭示了真正的基板的砂桩挖掘洞穴建设过程中，除了一个明显的显着的平等间距个别洞穴，被证明是真正的通过对相关函数分析。这些特征表明，洞穴层位登记同期的遗迹群落，没有palimpesting洞穴。洞穴视野的不规则垂直分布，尽管近连续的半日沉积记录，建议是一个人工制品的空间斑块的洞穴群落在沉积环境中，不完全注册的垂直剖面与高时间，低空间分辨率。该序列证明，洞穴palimpsesting不是一个不可避免的遗迹学结论的沉积停滞，并证明了间歇性的古生态保真度的地层记录在小的时空尺度上记录在露头。
A heterolithic tidalite succession yielding spring-neap bundles is newly reported from a mid-Carboniferous (Serpukhovian) section of the Alston Formation of Northumberland, England. The rhythmite records deposition over an interval that can be confidently calibrated to at least 84 lunar days, and attests to a non-negligible tidal range in parts of the Northwest European Seaway in the late Mississippian. The tidalite is notable for the presence of a striking crowded Skolithos ichnofabric on both bedding planes and in vertical section. Bedding plane expressions of the ichnofabric reveal true substrates of sand piles excavated during burrow construction, in addition to an apparently remarkable equal spacing between individual burrows that is shown to be genuine through pair correlation function analysis. These characteristics show that the burrowed horizons were registered by contemporaneous ichnocoenoses, with no palimpsesting of burrows. The irregular vertical distribution of burrow horizons, despite a near-continuous semi-diurnal record of sedimentation, is suggested to be an artefact of spatial patchiness of burrowing communities in the depositional environment; imperfectly registered in a vertical profile with high-temporal, low-spatial resolution. The succession proves that burrow palimpsesting is not an inevitable ichnological conclusion of sedimentary stasis, and attests to intermittent palaeoecological fidelity of the stratigraphic record at the small spatio-temporal scales recorded at outcrop.