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.

中文翻译：

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石炭纪潮汐韵律岩中非重印的拥挤 Skolithos ichnofabrics：从露头的时空偏差中解开生态特征

来自英格兰诺森伯兰郡阿尔斯通组的中石炭纪（Serpukhovian）剖面的异质潮汐岩序列产生了春季 - 小节束。韵律石记录的沉积时间间隔可以自信地校准到至少 84 个阴历日，并证明密西西比晚期西北欧洲航道部分地区的潮差不可忽略。潮汐岩以引人注目的拥挤Skolithos的存在而著称床上用品平面和垂直截面上的 ichnofabric。ichnofabric 的层理平面表达式揭示了在洞穴施工期间挖掘出的沙堆的真实基质，此外，通过配对相关函数分析表明，各个洞穴之间明显相等的间距是真实的。这些特征表明，洞穴层位被同时代的 ichnocoenoses 记录，没有洞穴的重印。尽管有近乎连续的半日沉降记录，但洞穴层位的不规则垂直分布被认为是沉积环境中洞穴群落空间不规则性的产物；在具有高时间、低空间分辨率的垂直剖面中不完美地配准。